In order to help PipeChina smoothly implement the "Five Optimizations and One Innovation" (including normalized design, intensive procurement, mechanized construction, digitized delivery, intelligent operation and innovative leadership), both principal framework and practices were studied for advanced technologies to predict the consumption demand on natural-gas resources in the recent decade by means of literature survey. Results show that (i) at present, the commonly used prediction methods mainly include four kinds of prediction, like empiricism, market investigation, time series, correlation, and combination model; (ii) these methods are available for different project background due to their difference in running mechanisms and data source; and (iii) both empirical and market investigation prediction methods are more suitable for judging rough development trend, while both time series and correlation prediction ones can better reveal coupling laws among model elements. And combination model is able to meet the need of multi-scenario prediction. In conclusion, prediction models have their own advantages and disadvantages, and the combination model is conducive to capturing further input information, reducing prediction errors caused by single modeling, and further improving fitting superiority under the guidance of digital technologies, so as to provide additional reference with rational decision-making and optimal planning.

Natural-gas markets in the United States boast high openness after their evolution and reform for over a century. Meanwhile this country is not only the world’s largest natural-gas consumer and producer at the moment but one of the most advanced countries in pipeline technologies. Thus, some American innovative approaches on the investment recovery mechanisms were analyzed for renovating urban-gas pipelines. Moreover, the financial subsidy plan from the federal government was discussed. In addition, And a lot of renovating successes were summarized in an effort to guide China’s renovation. Results show that (i) considered the particularity of gas industry, it’s recommended to adopt a system of floating rate to set up the reasonable rate according to the seasonal difference in gas consumption; (ii) using the way of the American government for reference, we may set up technological awards or R & D fund to encourage technological application; and (iii) public information about American pipelines may offer experience for our policy formulation, normalization, and examination and supervision in public information, and further standardize and implement this disclosure. In conclusion, learning from American innovation in the cost recovery mechanisms of gas pipelines’ renovation, we shall take their essence and combine practice application while localizing the experience absorbed, and to further find the solution in the investment return of the renovation.

For underground gas storages (UGSs), the value property to make a profit from natural-gas trade through pricing fluctuation is known as the financial value. And this value in storage capability is important for the profit made via UGS business. So, pricing discrepancies among Europe, America and China were analyzed to further discuss assessment models on the financial value in order for UGS's value promotion. Moreover, some assessment ideas about this capability, which are also applicable to different development stages in China's gas market, were put forward, and a historical pricing model was built for this assessment at low degree of marketization. Results show that (i) the pricing modes in Europe and America at high marketization are characterized by high fluctuation and mobility, while the mode in China with low characteristics; (ii) taken these low fluctuation and mobility together with future changes into account, the built historical pricing model may be used to evaluate the financial value at low marketization, and the least square Monte Carlo simulation is regarded as another evaluation model for the improved price marketization; (iii) the historical model has its own features, such as calculation only for a single curve on historical price and functionality at the variable trading cycle. The lower the marketization is, the more credible the model evaluation is; and (iv) this pricing model is able to be applied to the value assessment on China's UGSs under existing pricing mode, capture the optimal working gas capacity at the high- and low-record price, and calculate relevant cash flow.

The gas storage peak-shaving has turned into a universal technology to alleviate consumption summit as the shortage of gas source during peak gas consumption becomes increasingly serious. And rationally selecting the peak-shaving mode is the primary prerequisite for ensuring safe and stable gas supply. In order for better cost sharing in LNG storage and peak shaving projects, one item in Ya'an city of Sichuan province was taken as an example to predict its efficiency after some analysis on the status quo at home and abroad. Moreover, this item was optimized and improved to address the problem on its economic indicators not meeting standards. The affordable price was analyzed for gas enterprises by means of questionnaire over their price in peak-shaving services. Combined the questionnaire with real calculation, the sharing proportion was recommended for the peak-shaving costs. Finally, three cost-sharing schemes were individually made for relevant government departments, gas enterprises and end users based on the calculated results. It is demonstrated that (i) governments should reasonably differentiate between basic and nonbasic demands, fully think over upstream and downstream industries, enterprise development, livelihood security, economic benefits, and social fairness and justice, complete livelihood protection very well, improve policies on subsidy for disadvantaged groups, and ensure the groups' living gas unaffected by price linkage; (ii) gas enterprise should ensure their reasonable profits through reasonable sharing of LNG storage peak-shaving costs with end users, which embodies their responsibility as the main part of supply guarantee and the social attribute which gives priority to ensuring people's livelihoods; and (iii) end users should thoroughly consider the economic burden capability in needy families to eliminate individual spending as possible while keeping the normal production during peak consumption periods and seasons, ultimately to achieve mutual benefits and wins for multiple sides. In conclusion, the recommended sharing proportion may provide reference for similar projects.

Expanding gas-fired electricity in Sichuan Province is an important initiative to achieve the "dual carbon" goal, improve the peak shaving and frequency regulation for electric power, and ensure the safe and smooth power supply. In 2022, Sichuan issued some policy recommendations and guidance on the two-part pricing of gas-fired electricity. It is pointed out that the price of gas electricity capacity shall recover the fixed investment costs according to certain reasonable return, and gas price is linked with electric price for adjustment. So, policies on two-part electricity price in China and some provinces were sorted out. Furthermore, the component of gas-fired electricity costs in Sichuan was investigated. Then, recovery mechanisms of gas electricity investment were discussed, and the capacity price was calculated. Finally, the relevant principles and methods of calculation and regulation paths were suggested for this capacity price. Results show that (i) issued policies on the price of gas-fired electricity according to location conditions is conducive to promoting this sector in the healthy and sustainable development; (ii) the two-part pricing is available for recovering the fixed costs, obtaining reasonable incomes through capacity price, promoting the orderly, healthy and sustainable development of gas-fired electricity industry in Sichuan Province, and achieving the gradual connection with the power market through lower energy price to enhance the market competitiveness; (iii) the capacity-pricing guidance is in light of two principles, namely "who is beneficiary, who is responsible" and "reasonable sharing and dynamic adjustment"; and (iv) for gas-fired electricity, the capacity-pricing standard, which is in accordance with the internal rate of return of capital fund (8%), can be 28 yuan/kw·month for F unit commitment, and the capacity charge is regulated and shared by provincial large industries together with commmon industrial and commercial households.

Sichuan-Chongqing area is not only a major gas production base but a considerable gas consumption area in China. Some problems and schemes about the mechanism reform of loop pipelines were analyzed for this area in order for boosting a reform on price mechanism of pipeline transmission. Moreover, both advantages and disadvantages as well as problems facing in various schemes were summed up. Many solutions were made. Results show that (i) reform thoughts on transmission price of loop pipelines in this area are put forward as follows, namely, it is necessary to implement a unified user price and a unified pricing in this area, to charge transmission fees from users for upstream enterprises at transmission ends and then to settle the receivable fees with other transmission parties. From aspects of the settlement between upstream enterprises and transmission parties, the rules of old way for old pipelines and unified transmission price for new pipelines were implemented for branch pipelines inside Sichuan-Chongqing area; and (ii) there exist some problems in the reform schemes, such as the identification of distribution problem, the acceptance of each main agent and the construction of high-cost pipelines for people's livelihood. And countermeasures are made, such as setting the minimum load rate, maintaining the original user preference, keeping the transmission price rate of old pipelines, and identifying the high-cost pipelines for people's livelihood. Two suggestions are proposed for the next reform and relevant research, at first to analyze controls on the price mechanism reform of pipeline transmission in Sichuan-Chongqing area, including the economic and social benefits to users, transmission parties, upstream enterprises and the government, and to study its effect on the development of natural-gas markets and the optimization of industrial chain; secondly to establish an evaluation system on this mechanism reform in Sichuan-Chongqing area, and formulate relevant indexes and standards, evaluate the implementation effect and problems of this reform periodically, and adjust and perfect the reform schemes and policies in time.

In order to promote the capital optimization of state-owned petroleum enterprises and enhance their industrial creative ability, the state has successively issued numerous reform opinions to open up oil and gas exploration and development domains. Some problems have emerged one after another within three years after implementing the competitive transfer to mining rights, such as fast bidding pace and heavy preparation workload. Therefore, a set of evaluation method has been developed for bidders to solve these urgent problems in the fast and reasonable quotation way, which is better adaptable to complex bidding environment than the conventional economic evaluation. Results show that (i) the investment what has happened in one block shall not be included in the calculation of block value, otherwise the calculated value will be lower than the objective one, resulting in misjudgment; (ii) the bidding price shall not be involved in value calculation on the transferred block, and the evaluation efficiency can be improved greatly by taking the calculated NPV of the project as the highest quotation of its own; and (iii) it is unnecessary to take the influence of financing channel into consideration when evaluating the block value, and all exploration and development investment shall be treated as its own fund. Thus, the calculated results can reflect true value of the block. In conclusion, the optimized economic evaluation method can reduce evaluation workload greatly and improve the response speed to the quotation effectively.

As the accelerating market-oriented natural-gas reform in China, such fair and open infrastructures as pipelines and their connectivity have reinforced the competition in natural-gas upstream and downstream markets after the establishment of PipeChina. However, mechanisms to form previous segmented price is not able to mirror a competitive relation between gas price and source under market conditions. So, changes in China's natural-gas industrial chain and value chain after the pipeline network independence were investigated and the price transmission was examined from the perspectives of industrial chain and value chain. Then, integrating these two chains, a "dual-chain" mode was proposed. Furthermore, both price formula and natural-gas competitiveness analysis model (NGCAM) were constructed. At last, the competition among national and regional natural-gas markets was analyzed by this model. Results show that (i) the newly-constructed model can, to some extent, represent operating mechanisms on these markets after opening the pipeline network, imply the price transmission in the natural-gas industrial chain, and highlight the competition among gas-gas, gas-liquid and liquid-liquid in this chain; (ii) in terms of national market competitiveness, this model presents the competition among gas sources such as domestic gas, imported pipeline gas and LNG, and the distribution of preferential markets, namely, LNG resources in coastal areas gradually infiltrating into inland and unconventional gas like coal gas into mid-eastern China with the help of the pipeline network, resulting in an increasingly prominent collaborative development among gas sources; and (iii) in terms of regional market competitiveness, the model assumes competitive results among various sources and many changes of supply structure in the next markets, indicating that as a sort of flexible regulatory resources, LNG is supportive to pipeline gas each other, and its source has became more competitive than before.

The natural-gas chemical industry in Sichuan-Chongqing region focuses on the production of basic chemicals like methanol, synthetic ammonia and carbamide. To encourage it with the high-quality and sustainable development, some research visits were conducted in relevant enterprises inside this region. Moreover, opportunities and challenges for this industry were discussed according to some analysis on policy orientation as well as domestic and international situations. Results show that (i) the state invests more in natural-gas exploration and development and is stepping up the construction of natural-gas production capacity, causing an increase in resource supply. Meanwhile, the natural-gas consumption in Sichuan-Chongqing region tends to rise evidently following the economic growth together with the support of national and local policies, which may provide guarantee of raw materials for the sustainably industrial development; (ii) the cost gap between natural gas-based and coal-based chemical enterprises is narrowing. In the natural-gas chemical industry, management is optimizing and technologies are improving in addition to complex and ever-changing international situations, which may offer opportunities to this industry with the high-quality development in the region; and (iii) the natural gas-based chemical industry in China only accounts for a smaller share and weaker discourse power of the whole chemical industry, new and expanded chemical projects are limited, and raw gas is short supply in heating seasons, which may also restrict its industrial development. It is concluded that the natural-gas chemical industry in Sichuan-Chongqing region will hold a high growth rate in the 14th Five-Year Plan period.

Insufficient capacity of gas storage and peak shaving is one of the short boards in the construction of domestic natural gas production, transportation, storage and sales system. The construction of underground gas storage (UGS) is characterized by great site selection difficulty and long construction cycle, so in order to meet the need of peak shaving in more areas, single-well UGS emerges as a new mode at the proper time to act as an important supplement to UGS. In order to demonstrate the economics of rebuilding single-well gas reservoir into gas storage facility, this paper establishes the corresponding economic evaluation method by considering recycling cushion gas at the end of the evaluation period based on the technical and economic characteristics of rebuilding single well into UGS. And the following research results are obtained. First, the feasibility of the economic evaluation method considering the recycling of cushion gas is demonstrated with Well WC1 in the northwestern Sichuan Basin as an example. It is shown that the overall internal rate of return (IRR) of the project is 6.78%, which is higher the basic rate of return (6%), which proves the economic feasibility of the scheme from the perspective of financial evaluation. Second, the influences of evaluation methods on scheme benefits are compared. It is indicated that the overall IRR of the scheme without considering the recycling of cushion gas is 6.17%, which is lower that considering the recycling of cushion gas 6.78%. Third, two suggestions are recommended. First, it is recommended to popularize the new UGS construction mode of rebuilding single well into UGS, and especially in the resource areas with great site selection difficulty and peak shaving demand, existing productivity and depleted gas reservoir resources in the areas shall be used sufficiently to explore the rebuilding of single-well gas reservoir into UGS. Second, it is recommended to consider the recycling of cushion gas during economic evaluation, so as to solve the difficulty in the economic demonstration of rebuilding project.

Speeding up the natural gas industrial development and increasing the natural gas proportion in primary energy consumption are essential tools to quicken the construction of clean, low carbon, safe and efficient modern energy system. The next industrial evolvement faces growing uncertainties for China is in an important period of energy transformation. In order to scientifically forecast the consumption demand of natural gas in China, this demand under three different alternative scenarios (baseline, deep emission reduction and low emission reduction) was analyzed by taking the LEAP model as the base. Results show that (1) the domestic gas consumption increases at a high speed under the three scenarios from 2020 to 2030, and the growth will slow down after 2030; (2) in the long run, there is a steady demand increase. Under the three scenarios of low emission reduction, baseline and deep emission reduction, the consumption demand will be stabilized at 4 500×10⁸ m³, 4 700×10⁸ m³ and 5 200×10⁸ m³, and will peak in 2041, 2045 and 2048, respectively; and (3) the demand structure is substantially stable also under these scenarios. In terms of the consumption in various industries, manufacturing is at the top proportion of gas consumption demand, making up around 50% of total demand, among which resource processing, mechanical and electronic manufacturing, and light and textile belong to subdivided ones with the highest demand on natural gas.

Building-distributed energy projects as emerging and comprehensive ones attract more extensive attention. To set a reasonable natural-gas price for these projects, one building-distributed energy project with different energy-supply areas varying from 5×10⁴ m² to 50×10⁴ m² was taken as an example to develop a model on cogeneration cooling, heating, and power installation and equipment operation. Furthermore, an acceptable boundary gas price at the demand side was calculated according to operation cost, and thus the price strategy at the sales side was formulated. Results show that (1) at present, for sake of unsatisfactory gas/power price ratio, all terminal natural-gas companies shall focus on saving energy and reducing emission, seek certain policy support promulgated from local government, strive for fiscal and tax subsidies, and further expand new domain in a natural-gas consumption market; (2) building-distributed energy projects shall be popularized. And these terminal companies may advance participating in and track the gas consumption projects on middle- to large-sized buildings such as commercial complex, concentrate the newly built hospitals as well as commercial and office complexes with the energy-supply area over 10×10⁴ m² and stable energy consumption for cooling, heating, and power, and promote these projects in an orderly way according to differential pricing mechanism.

Natural gas is a kind of green and efficient energy. To accurately predict its demand is of great significance to the policy making, production, and trade of natural gas. However, in some traditional prediction methods of both regression analysis and grey model, only time factor is considered, resulting that the prediction accuracy cannot be guaranteed. In recent years, artificial neural network has been proved to be efficient and accurate in natural-gas prediction, but the current research mainly focuses on algorithm optimization, even less on the influence factors of natural-gas demand. So, BP neural network model was established to qualitatively analyzed these factors. Then, feature selection was done on the influence factors by means of grey correlation degree method (GRA), average influence value method (MIV), and principal component analysis (PCA), so as to simplify and optimize the neural network model to improve the prediction accuracy. Results show that (1) these three methods can significantly reduce the prediction error in neural network, among which MIV method as the best one may decrease the average relative prediction error from 9.077% to 0.983%; and (2) the prediction results of natural-gas demand from 2019 to 2025 by the BP neural network model and feature selection by the three methods are basically accordant, while those by the traditional grey model are larger, indicating that this model has high prediction accuracy and reliable prediction results and can be used for predicting the middle- and long-term natural-gas demand.

Natural gas, as a clean and efficiently quality energy, is of great significance to reduce carbon emission, promote quality development of city ecological environment and economy, and realize the China's goal of "carbon peak and carbon neutrality". Therefore, forecasting the demand of city gas accurately is an important guarantee to city's healthy development. There are mainly two forecasting methods, namely single model and combination model. The combination one can effectively integrate the information in single model, so as to further reduce the errors of single model and improve forecasting accuracy. In order to accurately forecast the demand of city gas, a combination forecasting model on natural gas demand has been established by referring to the Shapley benefit distribution theory of cooperative game theory, considering the difference among gray GM (1,1) model, exponential smoothing model, and gray Verhulst model and their characteristics, and modifying the Shapley value, which may reduce some forecasting errors effectively. Results show that (1) the Shapley value can reduce certain influence caused by the difference among single models, better distribute the average absolute and relative errors among three single models, determine their weight more reasonably, and effectively improve the forecasting accuracy; and (2) the demand of domestic city gas will maintain an increasing trend during the 14th Five-Year Plan and is expected to reach 1995×108 m3 in 2025.

With oil and gas system reform as well policy liberalization, the domestic city gas industry faces with a new round of merger opportunity. So, how to scientifically evaluate the economic benefits in group city gas companies is increasingly important. In order to measure the benefits, some economic evaluation was implemented from the perspective of project, stake, and dividend levels. Then, the main factors influencing the benefits were summarized, including operation factors (such as determination of evaluation period, determination of main business income, and determination of gross profit margin), policy factors, cost estimation, capital expenditure, financing, and dividend rate. Finally, the application of cash flow method was analyzed from the aspect of the selection of evaluation caliber. Results show that (1) a model of cash flow with different perspectives shall be established to provide the basis for the comprehensive judgment of investment decision making; (2) the business forecast shall comply with the principles of comprehensiveness and authenticity, take full consideration of the risks instructed by each due diligence, give consideration to both historical operation logic and operation reality, and ensure the conformity of future forecast to the operation essence and development expectation in these companies; (3) the main influencing factors of business forecast shall be analyzed and determined one by one based on such factors as franchise rights, industry development status and expectation, industrial policies, historical operation data, and due diligence; and (4) another model of consolidated caliber is more accordant with the characteristics of enterprise group companies, i.e., complex organization structure and business mode.

In order to accelerate the development of shale gas in China and improve the safety support capacity of natural gas, a number of supporting policies have been issued successively since 2012 to promote the development of shale gas industry, leading to the great increase in shale gas reserves and production. Due to high development cost and big technological challenge, the healthy development of shale gas industry may be affected greatly by price and fiscal-tax policies. So, an comprehensive analysis was done from four aspects, i.e., interpretation of current domestic shale gas policies, influence of fiscal-tax policies on shale gas industry, development and related fiscal-tax policies on foreign shale gas industry (taking America as an example), and fiscal-tax policies on other emerging energy industries (e.g. photovoltaic industry). Results show that (1) the fiscal subsidy for shale gas represents a decreasing trend; and (2) it is estimated that the production cost of shale gas is about ￥0.17 /m3 higher than that of conventional natural gas, while the latest subsidy from the fiscal-tax policies is about ￥0.10 /m³, which may impact the enthusiasm of shale gas exploration and development companies to increase reserves and production. In conclusion, three suggestions are proposed to enhance the guarantee to national energy security, improve the producing capacity of domestic shale gas resources, and strengthen the resource development of shale gas exploration and development companies, including that (1) the state shall issue the quota in the "total amount of national reward and subsidy for unconventional natural gas in that year" in advance. And shale gas development enterprises shall do the calculation according to the deterministic fiscal subsidy data, so as to achieve the sustainable and benefit development; (2) the total subsidy shall be increased with the increase of development and utilization amount. In view of the development cost of shale gas, it is suggested to increase a provision that the total reward and subsidy shall be increased in a certain degree with the increase of development and utilization amount; and (3) for deep shale gas with burial depth more than 3500 m, finance allowance shall be increased, such as the subsidy of ￥0.40 /m³ and the subsidy period of five years.

There are abundant deepwater natural gas and tight sandstone gas resources in China. In order to speed up their economic and efficient development, both development status and national finance-tax support policy on deepwater natural gas, coalbed methane (CBM), shale gas, and tight sandstone gas in China were studied and comparatively analyzed. In particular, the policy necessity in the development of deepwater and tight sandstone gas was presented. Then, some suggestions on the finance-tax support were made for this development, including, (1) to improve the incentive mechanism of government subsidies for the production of unconventional oil and gas, and introduce the production of deepwater and tight sandstone gas into the list of government subsidies; (2) to establish the market mechanism on different production environmental gas source and different price; (3) to abolish the special oil gain premium of deepwater and tight sandstone gas or raise their threshold, and to establish the national risk exploration fund; (4) to add the deepwater and tight sandstone gas into guidance catalogue of key industry encouraged by the state; (5) to add the engineering equipment, environmental protection equipment, and large- and medium-sized safety energy-saving and water-saving equipment into ”Enterprise Income Tax Preferential Directory of Special Environmental Protection Equipment”, “Enterprise Income Tax Preferential Directory of Special Energy-Saving and Water-Saving Equipment”, and “Enterprise Income Tax Preferential Directory of Special Safety Production Equipment”, respectively; (6) to list the tight sandstone gas as a separate tax item of energy mineral and enjoy the preferential tax rate reduction; (7) to include the offshore (including deepwater) oil and gas resource tax into the central and local shared taxes; (8) to add the exploitation of tight sandstone gas into the resource tax regulations; (9) to reduce the constraint of economic index to the exploration and development of deepwater and tight sandstone gas; and (10) to apply the preferential policy of VAT immediate withdrawal to deepwater and tight sandstone gas by referring to CBM preferential policy.

Setting up National Oil and Natural Gas Pipeline Group Co. Ltd. (PipeChina) implies a reform acceleration and deepening in natural-gas market. After the cancellation of natural-gas gate price, it's crucial to establish another competitive market-oriented transaction price benchmark. Since 2021, a large fluctuation on international natural-gas price also highlights the importance of China's striving for both gas pricing and discourse power via forming an influential price index. There are gas pipelines built in Sichuan-Chongqing area with relatively mature market and more active market-oriented transaction, bringing about basic condition for natural-gas spot pricing. So, in order to establish the spot-price index of pipeline gas in this area scientifically and reasonably, a price-index compilation scheme was put forward adaptive to domestic industrial status and actual market price after systematically analyzing domestic and foreign experience and enlightenment in price index compilation. Results show that (1) a mature price index is surely the organic combination of scale and investability, and its compilation generally adopts relative or absolute number; (2) from the perspective of sample selection and data source, the price formed by centralized bidding in open market is the most basic data for index compilation. In the absence of such data, the data which is evaluated to construct a scientific evaluation system can be used as an effective complement; (3) domestic and foreign gas price indexes mostly adopt the weighted arithmetic average method; and (4) based on current situation of natural-gas market in Sichuan-Chongqing area, the spot price of pipeline gas often adopts the combination of transaction data + evaluation data as the basic data, which also takes transaction data as the primary as well as evaluation data as the auxiliary. In conclusion, in this area, the online transaction scale should be continually increased to lay a solid foundation for competitive spot-price index. Some support from the government should strive for ensuring the index sustainability and authority. What's more, the price-index derivatives should be further studied to continuously improve both price-index influence and credibility.

In order to accurately predict natural-gas demand and determine effective factors to avoid the influence of various dynamic nonlinear factors on this demand, six effective factors were pointed out from eight influencing ones (GDP, industrial structure, population development, total energy consumption, energy consumption structure, environmental regulation, unit energy consumption, and income level) according to an analysis on grey correlation degree model. Then, the multivariate linear regression model and the GM(0,N) model were established. After that, the optimal combination prediction model was also developed for the demand prediction. Results show that (1) the effective driving factors of China's natural-gas demand include GDP, population development, total energy consumption, unit energy consumption, energy consumption structure, and income level; (2) GDP development makes the greatest contribution to the demand increase, and the GDP increase can further promote the demand increase ; (3) the optimal combination model based on multiple factors can greatly reduce the sum of squares of prediction errors and perform well in nonlinear approximation prediction; and (4) it is predicted that, due to the influence of energy revolution, technological progress, and economic environment, the demand growth rate in China will present a decline trend during 2021-2025 and this demand will reach 4548×10⁸ m³ in 2025.

In order to keep pace with new situations and requirements on supply-demand market to continuously deepen reform and realize quality development under the "X+1+X" market-oriented mechanism which is formed gradually in the domestic natural-gas market, PetroChina Southwest Oil & Gasfield Company comprehensively adopted a new mode of natural-gas marketing with customer as the soul and creating value as the core, and implemented a whole-life-cycle management for natural-gas customers. Results show that (1) for natural gas, its whole life cycle can be subdivided into four management stages, i.e., identification and cultivation, growth and development, maturity and consolidation, and decline and termination; (2) there are different characteristics and objectives in these four stages. The objectives achieved in each stage are determined through standardized life-cycle customer management procedure. To realize these objectives is ensured by means of supporting tools; (3) four suggestions are proposed for implementing the whole-life-cycle management, including new customer tapping and development strategy during identification and cultivation stage, customer value promotion strategy in the growth and development stage, customer relationship maintenance strategy in the maturity and consolidation stage, and customer relationship retention and termination strategy in the decline and termination stage.

For China's natural gas, the market reform advances continuously, and the price mechanism is also one of the cores in the system reform of entire natural-gas industry. In recent years, with continuous development of China's offshore natural-gas technologies, the development mode and product form in offshore gasfields present diversified kinds, and the pricing mechanism is relatively complicated. In order to clarify domestic pricing mechanism for offshore natural gas, the reform process of price system was presented on the basis of pricing principles. Then, the latest pricing policies were analyzed. Finally, taking Guangdong Province as an example, the pricing difference and price level of the offshore natural-gas products were summed up based on development projects in offshore gasfield. Results show that (1) according to the latest edition of China's Central Pricing Catalogue, offshore natural gas is included in the category of unregulated gas and its price is oriented by the market; (2) all offshore gasfields that have been put into production are developed in the semi-offshore and semi-onshore mode and the product is in the form of natural gas. In the whole-offshore development mode, however, natural gas is processed and stored by means of FLNG/FCNG, and product form is transformed into liquefied natural gas (LNG)/compressed natural gas (CNG). The pricing mechanism of different product form is something different; (3) the price of offshore natural gas in Guangdong Province (in the semi-offshore and semi-onshore development mode) basically refers to that in the second West-East Gas Pipeline. In the future, however, developed in the whole-offshore development mode, LNG products will be affected by the international trade of LNG and their CIF price will be determined by commercial contract, referring to LNG import sources, while the CNG price will be referred to pipeline gas; and (4) the natural-gas market pattern of "simultaneous development of offshore and onshore, multi-source complementarity, and three-part separation" has been formed in Guangdong Province, and the natural-gas industrial development is typical and representative, which has certain value on the natural-gas pricing in other coastal provinces.

Along the supply-demand pattern of global energy is stepping into one stage of profound adjustment, a new round of energy revolution has already begun and the development of China's energy system is undergoing critical transformation. As the construction of Chengdu-Chongqing economic circle upgrades to a national strategy, the development of its energy system undertakes a more important mission, and the energy transformation and revolution are also a long-term arduous task. In order to solve the problem that energy-consumption growth in this economic circle slows down, improve the status that other problems on energy development quality and efficiency get obvious increasingly, and turn the development of energy system into the new foundation and driving force, the development direction of energy system integrated with five major development concepts was proposed for this economic circle to form some development strategic idea on energy system. Furthermore, their status quo and problems were sorted out, and some development prospect was forecast. Results show that in the Chengdu-Chongqing economic circle, (1) to speed up its energy revolution and to implement the five major development concepts of "innovation, coordination, green, opening, and sharing" are even more important; (2) its energy system overall develops faster and it belongs to a self-sufficient area, but the utilization efficiency of traditional energy is lower and the development of clean energy is slow; and (3) it is urgent to construct a modern energy system of cleanliness, low carbon, safety and high efficiency. As a kind of efficient clean energy, natural gas will step into a period of bright development.

Due to severe supply guarantee in every winter, PetroChina, Sinopec, and CNOOC expand the production of domestic gasfields and make great effort to cope with gas consumption peak in the winter. The production organization is optimized to give full play to productivity, while the supply to interruptible customers is limited and even stopped to ensure residential consumption. However, the customers are not offered with corresponding compensation. To this end, it is urgent for governmental departments and enterprises to establish a set of practical and operable peak-shaving compensation mechanisms for these interruptible customers from the aspects of national policy, supporting measure, and implementation step, so as to ensure their benefit effectively. Results indicate that peak-shaving compensation mechanisms for interruptible customers can be established by some measures as followed, (1) to establish the market-oriented compensation mechanisms and marketize the natural-gas price overall, (2) to establish the market-oriented trade mechanism of interruptible peak-shaving capacity and sell the gas to non-interruptible city customers in heating seasons by means of market-oriented transaction, so as to make profits, and (3) via government’s political compensation, to subsidize the loss of interruptible customers from supply stop, and (4) to offer them a certain discount in non-heating season through gas supply enterprises.

During surface construction in oil and gasfields, some traditional cost management modes cannot well cope with such problems as longer construction period, larger total investment, frequent price change of production factors, and purchasing additional facilities. So, a comprehensive dynamic cost management was presented for surface construction project. Moreover, some advantages were analyzed by comparing it with traditional modes from the aspects of design, procurement, and construction based on actual project and cost data. In addition, many problems in existing cost management were pointed out, and corresponding optimal strategies were made. Results show that (1) the comprehensive dynamic cost management can take the initiative of cost control from the early stage of project construction and ensure actual cost closer to the budget as possible; (2) affected by comprehensive dynamic cost, both capital and resource can be allocated reasonably in this construction process; and (3) the cost management can supervise and control the whole management process and realize a coordinated development of construction quality and cost control. In conclusion, its application can improve the scientific cost management for surface-construction projects in oil and gasfields.

In order to improve an accuracy to forecast a non-linear complex system, a new composite weight (so-called coweight) combination forecast model based on multi-dimensional information was proposed to achieve one goal of decreasing the sum of squared error (SSE) of combination forecast further. Firstly, one gray GM (1, N) model and another multiple linear regression model were combined to constitute three combination models by means of SSE reciprocal method, weighted average method, and entropy value method. Then, these three combination models were integrated to construct the coweight combination forecast model by means of the gray relation analysis method. Finally, it was verified by taking China's urban natural-gas demand forecast as the example. Results show that (1) the combination models can forecast more accurately than single forecast model and avoid some forecast risks in single model; (2) compared with the combination models, the coweight model has lower SSE and higher forecast accuracy; and (3) China's urban natural-gas demand in 2025 will be up to 288.4×109 m3 and the average growth rate is about 10 %. In conclusion, this coweight combination forecast model has good forecast performance in the non-linear complex system, and its forecast results can be used as the basis to formulate urban gas policies. What's more, China's urban natural-gas demand in the future will still present the trend of rapid growth.

In order to satisfy the requirements on sustainable development of underground gas storages (UGSs) in term of economic evaluation technology and to make full use of UGSs in both peak shaving and strategic gas reserves, some methods of economic evaluation on UGS construction projects were verified in their practicability by analyzing discounted cash flow approach, combined with seven evaluation steps, i.e., predict development index→ establish parameter system→ estimate investment→ calculate cost and expense→ estimate operation revenue and tax→ calculate economic evaluation index→ analyze uncertainty. Results show that, (1) the economic evaluation on these projects is to comprehensively analyze their financial feasibility and economic rationality on the basis of many schemes of geological and reservoir engineering, drilling and production, and surface engineering; (2) these evaluation methods are to analyze, calculate, and assess economic benefits according to cash flow in each year of evaluation period taking time value of capital into consideration; and (3) for these methods, their features are focusing on technological and economic comparison, scheme selection, overground-underground integrated analysis, project's ramp up rate, and risk analysis of peak-shaving gas volume.

In recent years, the state and the state-owned enterprises have been vigorously deploying special actions to improve quality and efficiency. However, the enterprises in different industries have various understandings and priorities on this improvement. For tight gas, an kind of indispensable and unconventional natural-gas resources, its exploration and development should deserve active actions to improve the quality and efficiency. So, some thoughts to improve the quality and efficiency of tight-gas development were summarized on the basis of its development strategic cost management, combined with the innovative management of core income and expenditure elements of financial identity. Results show (1) to pay attention to the top-level design of quality and efficiency improvement by taking the core income and expenditure elements as the main thread. (2) to insist on the coordinated development of income and expenditure elements, so as to realize innovative quality and efficiency improvement of element combination, (3) to strengthen integrated evaluation on income and expenditure elements and to promote one system of optimized quality and efficiency improvement, (4) to continuously set up certain concept of technology-economy integrated development and to promote innovation and coordinated development of management and technology, (5) to explore joint venture and cooperation modes and to control investment risk effectively, (6) to handle one supply-demand relationship of gas market and to improve tight-gas market competitiveness, and (7) to strengthen coordinated development of government and enterprise policies and to improve one level of incentive policies for tight-gas exploration and development. In addition, three policies and suggestions on how to accelerate the quality and efficiency improvement of tight-gas development in Sichuan Basin were proposed, including to strengthen strategic planning and arrangement, to actively explore some incentive policies on sharing excess return in market-oriented cooperation, and to further construct smart database and to improve one decision-making level.

Due to an unexpected outbreak of COVID-19 and a continuous impact of low oil price, most oil and gas enterprises are facing with challenges in some domain of quality and efficiency improvement, digital transformation and intelligent development, market competitiveness, risk prevention ability, and innovative profitability. They intend to achieve large-scale development of low cost and high quality by active “distinguishing, replying, and handling the market”. So, in order to satisfy their needs and deal with the main impact of post-outbreak era and continuously low oil price, it is inevitable to provide information-oriented, digital, and intelligent services for the production and operation of enterprises' customers and carry out fast tracking, real-time monitoring, convenient communication, and effective decision making. After analyzing the current traditional manual customer service mode of oil and gas marketing and some characteristics, combined with advanced IT technologies and tools, one kind of customer service APP platform was set up for online oil and gas marketing by concentrating scientific talents, innovative design, and construction, so as to realize movable information communication and customer 24-h service interaction between enterprises and their customers whenever and wherever and to achieve remarkable information construction and application of innovative APP. Results show, for this APP, its application may increase the efficiency and quality of customer service, and achieve the time-sharing customer service.

With a continuous field development, some post evaluation on various oil and gasfield projects is carried out without interruption. In order to ensure the scoring results of post evaluation more scientific and instructive, the weights of post-evaluation indexes were redetermined by means of expert investigation method and analytical hierarchy process (AHP), combined with existing project post-evaluation scoring table. Then, one method of fuzzy comprehensive evaluation was practically applied to PetroChina Dagang Oilfield Company for verification. Finally, a way of reasonable post-evaluation scoring was explored on the basis of related practicability analysis. Results show that (1) the fuzzy comprehensive evaluation method processes scoring data on the basis of original expert's subjective scoring, which makes the post-evaluation scoring of oil and gasfield projects more objective and scientific; (2) it can reflect the scoring data of each project evaluation index directly, which is favorable to comprehensively evaluate project operation from different aspects; (3) it is more flexible and can satisfy the need of post evaluation; and (4) in the future, this method can be combined with digitalization. One more complete evaluation index system can established by using database, so that to select the evaluation index system is more flexible and diverse. Meanwhile, evaluation data is analyzed by using software, so that the evaluation conclusion can be reached while the project is scored. As a result, the evaluation results are more objective in the data level.

Recently, the government has announced a series of measures to supervise city-gas distribution price. In Sichuan-Chongqing area, city-gas development is relatively mature, and there are many city-gas enterprises with uneven development. So, the recent development of these enterprises was analyzed and the main problems about gas distribution price supervision were pointed out, including that, the overall profit level of gas sales business is too low and distributed unevenly; with domestic gas installation business as the soul, the profit growth mode is faced with great challenges; there are most city-gas enterprises only with extremely low effective assets; and the load rate of gas distribution pipeline network is lower. Results show that (1) the basic work to cope with this supervision shall be conducted by making measures, for example, speeding up gas distribution business separating from other businesses, performing independent financial accounting of gas distribution business, and establishing database of gas distribution related cost; (2) it is essential to construct an efficient pipeline system via optimizing the layout of both gas transportation and distribution pipeline network, and increase the load rate by means of information technologies; (3) it is necessary to increase enterprises' effective assets through strengthening infrastructure construction; and (4) it is necessary to strengthen cost control by optimizing cost structure and reducing non-permitted costs. In conclusion, To make policy on the gas distribution price supervision is crucial to China city-gas industrial development. All city-gas enterprises shall actively adapt to the development trend of market-oriented gas reform, and the implementation effects of policy need to be verified in practice, resulting in a healthy and sustainable development.

In order to clarify the cost structure of parameter wells for hydrocarbon geological survey, make the measures on cost reduction and efficiency improvement, and use reasonably the fiscal funds, this study analyzed the cost and expense structures of parameter wells with the implication and classification of parameter wells as the beginning point. Then, there are 43 influencing factors summarized, which can be subdivided into two categories (rigidity and flexibility). Finally, starting from a few flexible factors with controllable space, some suggestions on cost reduction and efficiency improvement were made. Results show that (1) to construct parameter wells for hydrocarbon geological survey, it is necessary to adopt more advanced construction technological scheme and service to control cost and avoid unnecessary expenses; (2) in the cost structure, material expense accounts for over 60 % of direct expense, so it is the key link of cost control. Overhead cost is an important factor to reduce indirection expense. It is necessary to perform real-time cost identification by using big data information platform and remove expense items that shall not be included in the tendering and bidding of public-welfare geological survey; (3) it is necessary to continuously improve the budget standard of geological survey, normalize the pricing bill, reduce the cost, and improve the efficiency scientifically and reasonably. In conclusion, parameter wells are important drilling engineering of basic public-welfare hydrocarbon geological survey. As continuous advancement, it is essential to strengthen the cooperation between financial and project personnel, promote bill-based pricing, and determine each cost quantitatively, so as to realize cost reduction and efficiency improvement continuously and support reasonable use of fiscal funds.

Establishing National Petrleum and Gas Pipeline Network Group, Co., Ltd marks the substantial breakthrough in the reform of national oil and gas system, which pushes this reform into a new stage. In its transitional period, it is quite important to actively and steadily promote the transition of natural-gas industry from "integration" to "releasing both ends and controlling the middle part", and it is necessary to deepen another reform of gas price mechanism coordinately. So, this study comprehensively analyzed the development history, status, and existing problems of price mechanism in all links of industrial chain, and made some suggestions on the mechanism reform to meet the needs in this transitional period. Results show that (1) to implement the new version of the Central Pricing Catalog means that the cancellation of gate price will not be far off. It is suggested to continue using the current management mode of gate price and initiate the sales mode based on gas source in this period, and then liberalize gas source and sales prices appropriately according to reform progress; (2) the current pipeline transportation price is faced with some problems of pricing range and price system design. It is suggested to subdivide the transportation cost into "basic transportation cost" and "node allocation cost" by functional demand, and the cost sum is the permitted one by the corporation; (3) the current gas-storage price is also faced with many problems including difficult recovery of gas storage and peak-shaving cost. It is suggested to apply the service cost method to the pricing in the transitional period, namely "cost + permitted profit"; and (4) domestic energy based on natural-gas metering and pricing has fundamental conditions of technology, infrastructure, and system. It is recommended to speed up formulating a plan to implement the gas energy metering.

According to the new version of Central Pricing Catalog, the gas purchase and sales price in underground gas storages (UGSs) has been liberalized to set by the market since 2020. Under the background of promoting the separation of gas production, supply, storage, and sales, UGSs begin to operate independently, so it is imperative to speed up constructing a price mechanism of storage and transportation fee. Therefore, several methods for calculating this fee were comparatively analyzed and selected after their necessity was studied. Results show that (1) UGSs are one important means to adjust gas supply and demand and optimize pipeline operation. The storage and transportation fee isn't priced independently, which may prevent the direct reflection of UGSs' economic value and isn't beneficial to analyze the profit ability, and impacts the initiative to invest and construct some UGS projects. In 2016, the nation issued many related guidelines, according to which, gas-storage facility fee shall be priced by the market or by both parties through negotiation, but the reform of gas system was lagged, so it hasn't been fully implemented; (2) according to the method for calculating the UGSs' cushion gas volume and the composition of investment and operation cost, it is eventually determined to take these UGSs rebuilt from oil and gas reservoirs as the base to build up the model to calculate the storage and transportation fee and to carry out a sensitivity analysis; and (3) the net present value (NPV) method can be used to calculate the storage and transportation fee for these rebuilt UGSs. By optimizing certain operation to increase the working gas volume, the fee can be reduced the most efficiently and the UGSs' benefits can be maximized. All results may provide the reference for calculating the UGSs' investment return price and are of guiding significance to improve the market-oriented pricing mechanism in the future.

The new version of "Central Pricing Catalog" recently issued by National Development and Reform Commission releases some signals of further speeding up a marketization of gate price. Seeing that an effect of this new provision on the next natural-gas market in Sichuan-Chongqing area, this study analyzed many development experiences from some countries in European and America, and put forward development strategies for gas market in Sichuan-Chongqing area. Results show that (1) in this area, there are good infrastructures and resource markets, and huge potential to form market competition. At present, however, local gas sources are dominant, in which is shortage of enough competition condition, resulting that to form a mature competition situation needs long time; (2) gas produced from Sichuan-Chongqing area has two major markets to supply, including the area and coastal area. To let gate price in the coastal area go may directly lead to market competition in the coastal area and intensify horizontal competition in Sichuan-Chongqing area, so that a competition framework of gas market in Sichuan-Chongqing area will be reshaped; and (3) some suggestions are made for gas supply enterprises in Sichuan-Chongqing area, such as to cooperate with governments and other enterprises to launch incremental markets, to develop LNG industry chain to transport resources out of Sichuan Basin, and to implement low-cost strategies actively to improve their own price and market competitiveness.

At present, China is actively promoting a mechanism reform of natural-gas system. And one of the most important measures is to separate gas pipeline transportation from gas sales, however resulting in some challenges to sales business for oil and gasfields which develop gas market based on their own pipeline for a long time. So, it's necessary to change a new idea of gas marketing and establish a novel mode of gas sales, so as to stabilize and enlarge customer groups as well as increase both sales and market share. Taking PetroChina Southwest Oil & Gasfield Company as an example, this study developed one concept of customer manager system into gas sales and made some suggestions on its application to gas sales. Results show that (1) it's quite essential to implement this system to gas sales business in the company, conducive to promoting its sustainable development benefits, developing customers, optimizing service, consolidating market share, pioneering in market, promoting fair competition and cooperation, and fulfilling an increase in sales and efficiency; (2) according to current three-level marketing management structure adopted by the company, it's proposed to deepen this reform, develop a gas marketization, to construct a system's management structure through three stages (also categories); and (3) it's suggested to move rapidly towards specific job specification for this system and special job responsibility for sales customer manager, and to establish an assessment for this system so as to further construct and implement this customer manager system.

It's to some extent difficult to accurately predict an urban natural-gas demand due to seasonal influence, and temperature and population change. Moreover, it's beneficial to improve this prediction accuracy by different models or methods to adjust and correct prediction results. Based on some results obtained from both gray Verhulst and linear regression models, another compound model of gray regression based on metabolic principle with metabolic functions was developed. By virtue of this model, the urban gas demand was predicted accurately so as to provide many scientifically theoretical data supporting for establishing gas supply-demand balance mechanisms. Then, Hubei Province was taken as an example to carry out gas demand prediction. Results show that (1) this compound model can reduce some prediction risks existing in single model and play a certain role in reducing prediction errors, and its results are more stable and reliable; (2) the metabolism model is modified from the original prediction model and can increase prediction accuracy significantly, and its results can be taken as the reference and basis for relevant enterprise departments and government departments to make decisions scientifically; and (3) the compound prediction model is characterized by good fitting, high accuracy, and stable and reliable results, and it can be used for short-term demand prediction of urban natural gas. Its application is practical.

With an increase of natural-gas utilization scale in recent years, more and more attentions have been paid to constructing gas-storage facilities. In order to intensively and efficiently construct these facilities in Yunnan Province, we propose one idea on this construction by means of using coal gas, biogenic gas, and pipeline gas as a whole. For pipeline gas, one contradiction between sales volume and development quality can be solved by planning different gas source, and intensive and efficient constructing gas-storage facilities in the mode of multi-gas source joint development. And consequently, two aims to increase its value and to realize win-win of multiple gas source in different links among multiple parties can be achieved. Results show that (1) in Yunnan Province, the productivity of both coal gas projects (2×10⁸ m³/a) and biogenic gas projects (1×10⁸ m³/a) can provide an effective guarantee for the supply of natural gas in province, (2) some analysis on consuming characteristics and construction status of gas-storage facilities indicates that both coal and biogenic gas development is operable with good economic benefit; and (3) it's suggested to take this construction as the opportunity to revitalize multiple gas source and increase utilization efficiency of gas-storage facilities, so as to develop the idea of guaranteeing gas supply with pipeline gas as the soul, and with coal and biogenic gas as the supplement, and to effectively fulfill national policies and requirements on strengthening the construction.

Under the background of developing "clean, low-carbon, safe, and efficient" energy, it,s necessary to strength some studies on the application of clean-energy vehicles in order to speed up natural-gas utilization, improve energy security, and promote energy reform. Based on the popularization and application of LNG heavy trucks, we adopted a method of SWOT to analyze the advantages, disadvantages, opportunities, and threats of their popularization and application from four aspects of gas, vehicles, stations, and policy. Then, several suggestions were proposed. Results show that (1) some development-type and adjustment-type strategies for the popularization and application are established, including, grasping opportunities to expand development foundation, making use of existing foundation and advantages to the uttermost to carry out multi-way popularization, and implementing corresponding policy of halving the toll of LNG heavy trucks in a certain period; and (2) based on the integration of advantages with both opportunities and challenges, many change-type and defense-type strategies for the popularization and application are established. And they specifically include formulating the popularization plan dedicated to LNG heavy trucks according to national policies, issuing the policies of government subsidy to purchase LNG heavy trucks, strengthening the completion of standard systems, and improving the construction of vehicle performance and after-sale service system further.

The pipeline business is a key area in deepening the reform of natural gas industry. In recent years, several regulations and policies related to the construction, operation and supervision of natural gas pipeline facilities has been successively issued in China and the government has made some beneficial attempts to reform natural gas pipeline. However, the problems existing in pipeline investment construction, the third party fair entry and government supervision etc. are urgent to be settled. Based on the analysis on the experience of natural gas industry reform in America, EU and Russia and combined with the basic national condition and natural gas operation and management models of China and based on the principles of implementing step by step, relevant suggestions are proposed.

With regard to the third-party access system in natural gas industry proposed to be implemented in China, the paper analyzes the 7 factors about the third-party access, including third-party access services and rate, capacity assignment mechanism, congestion management, rule of equity, capacity transaction and access conditions. For the 7 factors, the paper puts forward following suggestions. The operators can formulate gas transmission pipeline contracts with different contract terms and realize the optimal utilization of pipeline resources through the combination of long-term and short-term contracts. The operators can formulate and publish a calculation method of residual capacity so that a capacity auction platform can be constructed if a third-party user reaches a certain capacity. At the initial stage of market development, the rule that the unused capacity of a user will be regarded as capacity loss can be implemented. At the later stage, the rule that the unused capacity of users should be regarded as capacity loss before a specific date can be implemented. The supervision organization can formulate balance regulations to provide legal guarantee for the smooth implementation of third-party access. At the initial gas transmission pipeline network access stage, the pipeline operators can provide flexible services for third parties and allow 10 % fluctuation of contract gas volume and they can lower floating rate to 5 %（or below）when the market development becomes mature. When the development of gas pipeline network enters a mature stage, a national pipeline network company and national level oil and gas control center can be established to have unified allocation of pipeline network resources.