Nowadays academic circles are less on exclusive discussion on the "exploration-to-production" system in the context of the latest Mineral Resources Law, especially on the distinctiveness in petroleum industry. There exist problems on this system before the latest law implementation. Therefore, some exploration-to-production factors favorable for enterprises after this implementation were meticulously analyzed by means of literature survey and policy interpretation. Then, the positive driving effects of the "direct express" system of exploration and production on petroleum exploitation enterprises were also figured out. Finally, challenges and suggestions were addressed and made for implementing this "exploration-to-production" system. Results show that (i) after implementing the latest law, the exploration-to-production is conducive to the enterprises, namely direct conversion from exploration to production, optimized auxiliary regulations, and enhanced rights and interests protection; (ii) the system's positive driving effects include defining both rights and interests in mining rights holders, improving development efficiency, reducing rights and interests risks, promoting technological innovation and management optimization, emphasizing mining rights acquisition and protection, and achieving integrated exploration and production of mineral rights; and (iii) four challenges up against these enterprises contain increased compliance costs, intensified market competition, higher requirements to resource reserves, and increased pressure on ecological environment protection. Two suggestions are made for the "exploration-to-production" system: nationally, to construct operational guarantee mechanisms to implement this "direct express" system; and at the enterprise level, to set up a three-dimensional exploration system with overall perspectives.

In this study, both status and challenges on natural-gas cooperation between China and Central Asia were discussed by means of both comparison and method of supply-demand balance analysis in order to ensure the security of imported natural gas transported across pipelines in western China. Moreover, some suggestions were made for this cooperation. Results show that (i) the global proportion of gas resources undiscovered in Central Asia accounts for 12.1%, while Kazakhstan, Turkmenistan and Uzbekistan only around 5% of the global production, indicating greater potential in natural-gas development; (ii) the imported natural gas from Central Asia accounts for 24% of China's total gas imports and 60% of China's total pipeline gas imports, providing essential guarantee for gas consumption in Northern China in winter; (iii) net reserves and net production from China's petroleum companies in Turkmenistan rank the first among other companies in this country, and the gas transmission capacity of the China–Central Asia natural-gas pipeline is equivalent to 60% of that in the Central Asia–Europe pipeline, indicating there is still something to be improved; (iv) the pipe transportation rate for natural gas exported from Central Asia to China is higher than that of other typical transit countries; (v) in Central Asian countries, gas consumption increases, resulting in a trend of prioritizing their demand; (vi) the China–Russia pipeline built in 2022 leads to a decrease of pipeline gas imported from Central Asia by 19.2% compared with that in 2021; and (vii) affected by Tajikistan situation, constructing D sub-line in China–Central Asia gas pipeline has been obstructed. It is suggested to carry out oil and gas survey and cooperative mapping for small- and medium-sized basins in eastern Kazakhstan, and strengthen cooperation in pipeline upstream gas sources and industrial chain, as well as energy diplomacy with Central Asia.

With the Lower Permian Shihezi 1 Member as the major payzone, most gas wells in Da 28 well block suffer from frequent liquid accumulation and water flooding. Popular drainage gas recovery fails to resume effective production. Thus, the process of cyclic gas lifting was analyzed from aspects of technical principles and applicability. Then, two typical frequently-flooded wells, D28-A and DPH-A, were selected from this block for pilot test. Finally, compared with conventional drainage gas recovery, advantages were discussed for cyclic gas lifting in terms of its treatment effectiveness and economic benefits. Results show that (i) this gas lifting achieves remarkable availability. Both D28-A and DPH-A wells recovered to continuous stable production after this treatment. As of October 2025, their production resumed to 0.60 × 10⁴ m³/d and 0.45 × 10⁴ m³/d, and cumulative incremental of 164 × 10⁴ m³ and 542 × 10⁴ m³ and contribution rate of 57.7% and 53.3% to cumulative production, respectively; and (ii) this lifting attains great economic benefits whose incremental in both two wells within three-year evaluation period are predicted to be 6.04 million and 6.65 million yuan, respectively, with the input-to-output ratio of 1:2.66 and 1:2.79, implying its economic validity is greatly superior to that of conventional drainage recovery. In conclusion, for frequently-flooded wells with high water-to-gas ratio and certain formation energy, the process of cyclic gas lifting is a kind of drainage gas recovery that can gain high drainage efficiency, continuous stable productivity and good economic benefits. What's more, its successful application to frequently-flooded wells in Da 28 well block verifies feasibility in technology and economy, and may provide theoretical guidance and practical foundation for the "low-cost and high-efficiency" development of flooded wells in similar tight gas reservoirs.

In S gasfield, there exists imbalanced suction during wellhead pressurization due to the mismatch between surface equipment and formation energy. Thus, some gas wells with sand and water production in this field were taken as objectives to discuss the dynamic relationship among sand control, and liquid and sand accumulation during this pressurization, and to point out multi-factor joint mechanism as a key role in stable operation. Additionally, integrating sand control and fluid drainage, an optimal technology of wellhead pressurization was developed on the basis of the collaborative coupling of both sand production control and liquid accumulation. Results show that (i) the best pressurization timing is determined. For some wells with liquid accumulation, the pressurization should be done when the tubing pressure drops to 1.1-1.3 times the export pressure. For others without liquid accumulation, the pressurization should be implemented when the tubing pressure drops to 1.1 times the export pressure; (ii) the developed system of wellhead pressurization takes the critical sand production flow rate as the upper limit, the greater values of critical liquid and sand accumulation as the lower ones, and the maximum allowable production as the reasonable production rate. Based on this reasonable rate, wellhead pressure can be calculated by means of node analysis. It is used as the benchmark and supplemented with gas lift for collaborative drainage when the critical sand production is insufficient; and (iii) several key calculation models are selected, including PT model to predict critical sand production, Hagedorn-Brown model to calculate wellbore pressure, and Li Min model or Tan Xiaohua model to evaluate critical liquid accumulation based on the water-to-gas ratio. In conclusion, the coincidence rate in field application is 82%, with pressure and production deviates of 10% and 8%, respectively, indicating higher reliability. What' more, the production-increasing impact in water-producing gas wells indicates a decreasing trend with the increase of water production, while others without water are jointly affected by dynamic reserves and permeability. The increase in production per unit of remaining dynamic reserves presents positive correlation to permeability when permeability over 40 mD, but is constrained by permeability when permeability lower than 40 mD. These findings may provide reference for the development of low-pressure wells in similar gasfields.

Adopted for ultra-deep wells in Sichuan Basin, traditional step-by-step wellbore cleaning during well testing features longer cycle, higher cost, and greater operational risk. Additionally, wellbore scaling and iron filling accumulation may lead to higher failure in lowering testing strings. Thus, the integrated drifting-scraping-fishing-flushing strings were applied to PS17 well, an ultra-deep one in this Basin, for on-site verification in an effort to address mentioned-above challenges while breaking through the application limitation of integrated cleaning tools in high-temperature and high-pressure (HTHP) wells. And these integrated strings were analyzed from aspects of technical principles, structural component, and optimizing methods of operating parameters. Results show that (i) the strings not only integrates hole gauge, HRC60 hardness wear-resistant alloy serrated scraping tool, and 5000 Gauss NdFeB strongly magnetic fishing, but also corrects the settling velocity of irregular scrap iron by means of fluid mechanics calculation and Stokes' law, so as to achieve the full-process operation of drifting, scraping, fishing and flushing in one trip. After their application, the single-well operating time is shortened from the traditional 7-10 days to 3 days, and the wellbore scale removal rate reaches 96%, 4.35 kg of sheet scrap iron with the diameter of over 8 mm have been successfully fished, and the fishing efficiency is 40% higher than that of traditional integrated tools; and (ii) this technology is applicable to ultra-deep wells with the well temperature between 0 ℃ and 220℃ and the pressure ranging from 0 MPa to 150 MPa. By replacing hole gauge and scraping tools, they can satisfy size requirements of the mainstream casing in Sichuan Basin, saving single-well costs by 150,000 to 200,000 yuan and increasing the string running success rate from 82% to 99.5%. In conclusion, the integrated drifting-scraping-fishing-flushing strings overcome technical bottlenecks of wellbore cleaning in ultra-deep wells in Sichuan Basin through functional integration and parameter optimization, and they greatly outperform traditional tools in terms of operational efficiency, working condition adaptability and safety reliability. What's more, this technology has economy and promotion value simultaneously, and can be widely applied to wellbore cleaning of ultra-deep wells in complex oil and gasfields in Sichuan-Chongqing area and Tarim Basin, providing technical support for efficient development of deep oil and gas resources in China.

Extra sour gasfields are confronted with extremely high safety risks during their development. And most emergency management modes suffer from bottlenecks, such as information isolation, response lag, and inefficient collaboration. Therefore, taken TSP gasfield with the content of hydrogen sulfide (H₂S) up to 251 g/m³ as an example, and integrated data driven and process reengineering, an intelligent system of emergency prevention and control has been constructed. It combines real-time production data, high-precision spatial data, meteorological and video data, performs multi-source information fusion and spatial analysis based on the GIS platform, and set up a closed-loop management scheme for the entire process of perception, analysis, command, and review. Results show that (i) with standard and intelligent emergency response, this prevention and control system can reduce the time for incident response and preliminary analysis from 10-15 minutes to less than 2 minutes; (ii) the collaborative command platform reduces the time for formulating emergency schemes and resource scheduling decision making from over 20 minutes to less than 5 minutes, resulting in the efficiency increase above 80%; and (iii) depended on full-process data recording, the review mechanism can provide scientific basis for this system in persistent optimization. In conclusion, for the intelligent system of emergency prevention and control, its smooth construction and application may provide a replicable successful mode for similar extra sour gasfields at home and abroad.

For natural gas, its energy pricing must be enforced. And to implement this pricing is accelerating in China, while the implementing difficulty lies in how to handle the interests of all parties. Moreover, the critical issue is to convert the volume price currently applied in each link of industrial chain into the energy price, which directly affects the interests of all parties in the chain and gets concerns of all parties. Thus, some relevant issues were discussed for promoting this pricing, and suggestions and specific methods were made and set up to resolve conflicts of interest among all parties. Results show that (i) it is not essential to convert the existing volume price into the energy price based on a unified reference calorific value, but adopt different calorific values for different situations; (ii) the higher calorific value is recommended, which is consistent with national standard; and (iii) the key solution to the implementation difficulty is to respect the interests of all parties, make suggestions to resolve interest conflicts, and provide specific methods of converting from volume price to energy price for the price complying with government pricing and guidance price, including gas price at gate station, pipeline transportation price, gasification expense at LNG-receiving stations, and urban gas price.

While deepening the "X+1+X" market-oriented natural-gas reform and accelerating the construction of a new pattern of production, transportation, storage and sales in China, all natural-gas supply and use enterprises shall improve their contract awareness and risk management skills. Based on the basic theory of modern contract economy, characteristics were pointed out for medium- and long-term natural-gas purchase and sales contracts, and the significance, principles, terms and measures were discussed for domestic supply and use enterprises to sign and execute medium- and long-term contracts, so as to provide theoretical support and practical reference for promoting China's natural-gas markets in the long-term sustainable development. Results show that (i) these contracts signed by these enterprises are mainly characterized by indefinite terms, openness and inclusiveness, and moderate flexibility; (ii) the main signing and executing principles are to comply with market rules, scientific allocation, supply and use bottom line, unified quantity and price, and voluntary selection; and (iii) the primary signing contents include dynamic workload allocation model, differentiated pricing model, default compensation agreement, and other clause agreement. To promote domestic natural-gas supply and use enterprises to flexibly sign and execute medium- and long-term purchase and sales contracts, it is recommended to ascertain the supply and use pattern, reinforce the publicity and guidance in effect, prepare purchase and sales contracts in a scientific mode, select signing and executing objects thoroughly, and organize the signing and executing in an orderly manner.

As a crucial institutional arrangement, the natural-gas futures market can improve the natural-gas market system, China's influence in the global energy market, and stability and competitiveness in industrial chain. Being a centralized and transparent tool for price discovery and risk management, natural-gas futures can actively diversify price fluctuation risks and optimize resource allocation efficiency through financial derivative mechanisms. Therefore, in combination with the development stage and practical foundation in domestic market, paths to promote this market constructed in China were discussed systematically by analyzing the construction experience from other natural-gas futures markets in the United States, the United Kingdom, Japan, and Singapore, Results show that (i) the development experience from foreign natural-gas futures markets demonstrates that the market construction should be coordinated with the maturity of spots markets and the process of industry system reform; (ii) in view of the resource endowment and supply-demand structure in China, the construction goals in China's market should focus on risk management, safe supply and stable price, rather than competing for international pricing dominance in the short term; and (iii) a mature natural-gas futures market is inseparable from clear supervision boundaries and effective risk prevention and control mechanisms. The selection of futures varieties is directly related to the liquidity and long-term effective operation of futures market, so the China's market construction should be advanced in stage based on domestic spots market maturity and resource structure, and international experience. Four suggestions made on variety selection and launch sequence are as follows: adhere to the basic path of "spots first and then futures"; drawing on the practical experience from Japan and Singapore, prioritize the launch of LNG futures contracts; and improving the variety system gradually with imported gas first and then domestic gas; take regional hubs as the starting point to promote the regional pilot work of pipeline gas futures construction.

Under the promotion of new quality productive forces, professional technical talents have grown into one of core driving forces for petroleum enterprises in the high-quality development. And their cultivation and echelon building are confronted with new opportunities and challenges. Taken enterprise needs into consideration, both path and countermeasures were discussed for the construction of technical talents in petroleum enterprises from numerous perspectives, such as echelon planning, training path design, technical standard system construction, and incentive mechanism optimization. Results show that (i) the system of "conventional oil and gas + unconventional oil and gas + new energy" integrated with "major energy discipline" can break through disciplinary barriers, promote cross-field collaborative innovation, and enhance technical skills and talent cultivation level for such enterprises; (ii) the design and completion of professional technical honor scheme based on job requirements and development stages, and the construction of development channel from "basic talents" to "strategic leaders" can strengthen talent motivation and promotion mechanisms; (iii) not only systematic hierarchical training path but standardized technical performance evaluation system will promote standard and scientific talent selection, promotion, utilization and motivation; and (iv) enhancing the integration of education and training, practical training, and lifelong learning, which combines with enterprise-school cooperation, scientific research innovation, and academic exchange, can setup a diversified talent cultivation ecosystem. In conclusion, these measures will stimulate the innovative potential of talents, promote the driving force of technological innovation, and build up a high-quality talent echelon that meets requirements of new quality productive forces, so as to provide strong support for petroleum enterprises in both technological advancement and core competitiveness enhancement, and solid talent guarantee for national energy security, and industrial transformation and upgrading.

Taken 10 development plans of tight gas in Sichuan Basin as samples, the main factors controlling on the unit full cost for tight gas were analyzed by using radar maps in an effort to improve economic benefits and risk management capability in tight gas fields, and achieve accurate prediction on development costs and scientific optimization on investment decision. Moreover, a probability model of unit full cost was established creatively by means of Monte Carlo method. Results show that (i) owing to joint effects of different resource endowment and high technological complexity, the unit full cost of tight gas is greatly higher than that of conventional gas, and it is 1.2-1.5 times that of conventional gas; (ii) at present, the unit full cost of tight gas is dominated by unit depreciation and depletion (accounting for 49.8%), and the operation cost mainly consists of maintenance and repair, exploitation operation, and downhole operation costs (accounting for 60.7%); (iii) six key cost factors are screened out through the analytic hierarchy process (AHP), and a Monte Carlo simulation objective function for the unit full cost is constructed on the basis of Gaussian, triangular, lognormal, and Gamma distribution to achieve comprehensive fitting analysis of multiple probability density functions; and (iv) from the perspective of fitting accuracy, the lognormal distribution function is greatly superior to other density functions. The P50 fitting result shows that the unit full cost is 1.049 yuan/m3, which is highly consistent with actual cost. In conclusion, these findings may provide reliable basis for benefit risk warning and optimal decision making.