In today’s society, with the continuous growth of energy demand, Bohai Oilfield, as an important offshore oil resource base in China, is facing increasingly severe challenges while contributing to national energy sec...In today’s society, with the continuous growth of energy demand, Bohai Oilfield, as an important offshore oil resource base in China, is facing increasingly severe challenges while contributing to national energy security. In order to improve the quality of water injection in the oilfield and gradually achieve efficient and stable production, Bohai Oilfield has launched a water injection well pressure optimization project, focusing on improving the efficiency and quality of water injection in the water injection wells, in order to achieve the optimal water injection plan. In practical work, P Oilfield continues to promote the development of water injection well pressure optimization projects, emphasizing practical exploration and continuous optimization of work plans. However, during the project implementation process, there were some problems, one of which was that the statistics of cumulative injection volume were not scientific enough, resulting in a more comprehensive and accurate presentation of the actual results of pressure optimization work. In the context of continuous improvement work, after careful analysis and research, P Oilfield has decided to optimize the cumulative injection rate algorithm to guide the oilfield’s water injection work in a more refined way, ensuring sufficient and good water injection, and enhancing the oilfield’s production efficiency and comprehensive competitiveness.展开更多
Cyclic pressure pulsing with nitrogen is studied for hydraulically fractured wells in depleted reservoirs.A compositional simulation model is constructed to represent the hydraulic fractures through local-grid refinem...Cyclic pressure pulsing with nitrogen is studied for hydraulically fractured wells in depleted reservoirs.A compositional simulation model is constructed to represent the hydraulic fractures through local-grid refinement.The process is analyzed from both operational and reservoir/hydraulic-fracture perspectives.Key sensitivity parameters for the operational component are chosen as the injection rate,lengths of injection and soaking periods and the economic rate limit to shut-in the well.For the reservoir/hydraulic fracturing components,reservoir permeability,hydraulic fracture permeability,effective thickness and half-length are used.These parameters are varied at five levels.A full-factorial experimental design is utilized to run 1250 cases.The study shows that within the ranges studied,the gas-injection process is applied successfully for a 20-year project period with net present values based on the incremental recoveries greater than zero.It is observed that the cycle rate limit,injection and soaking periods must be optimized to maximize the efficiency.The simulation results are used to develop a neural network based proxy model that can be used as a screening tool for the process.The proxy model is validated with blind-cases with a correlation coefficient of 0.96.展开更多
A novel model for dynamic temperature distribution in heavy oil reservoirs is derived from the principle of energy conservation.A difference equation of the model is firstly separated into radial and axial difference ...A novel model for dynamic temperature distribution in heavy oil reservoirs is derived from the principle of energy conservation.A difference equation of the model is firstly separated into radial and axial difference equations and then integrated.Taking into account the coupling of temperature and pressure in the reservoir and wellbore,models for calculating distributions of the reservoir temperature,reservoir pressure,and water saturation are also developed.The steam injected into the wellbore has a more significant effect on reservoir pressure than on reservoir temperature.Calculation results indicate that the reservoir temperature and pressure decrease exponentially with increasing distance from the horizontal wellbore.The radial variation range of the pressure field induced by steam is twice as wide as that of the temperature field,and both variation ranges decrease from the wellbore heel to the toe.Variation of water saturation induced by steam is similar to the temperature and pressure fields.The radial variation ranges of the reservoir temperature and pressure increase with steam injection time,but rate of increase diminishes gradually.展开更多
为了解决高压欠注水井降压增注中面临的难题,以定边油田低渗透油藏的主力区块为研究对象,研究该区块的高压注水井在线酸化增注技术。利用单步法酸液体系可以抑制二次、三次沉淀物和溶解堵塞物的特性,设计在线单步法酸化智能增注系统,通...为了解决高压欠注水井降压增注中面临的难题,以定边油田低渗透油藏的主力区块为研究对象,研究该区块的高压注水井在线酸化增注技术。利用单步法酸液体系可以抑制二次、三次沉淀物和溶解堵塞物的特性,设计在线单步法酸化智能增注系统,通过“监控表皮系数变化情况”判断“是否对目的层段持续酸化”,确保最佳酸化效果。室内实验和现场试验结果表明:G-智能复合酸对氟化钠和氟硅酸盐产生二次沉淀的抑制性最好,单步法酸液体系选择G-智能复合酸可以更好地抑制酸反应时二次沉淀物的产生;堵塞物在酸液+助渗透剂剂T影响下的溶蚀率在73.9%~79%之间,堵塞物溶蚀率高于仅加入酸液的,单步法酸液体系选择酸液+助渗透剂可提升堵塞物溶蚀率;与只注入助渗透剂T相比,注入G-智能复合酸+助渗透剂T的高压注水井的油压下降1.0~3.4 MPa,日注水量增加6.1~9.8 m 3,该技术优势显著。展开更多
文摘In today’s society, with the continuous growth of energy demand, Bohai Oilfield, as an important offshore oil resource base in China, is facing increasingly severe challenges while contributing to national energy security. In order to improve the quality of water injection in the oilfield and gradually achieve efficient and stable production, Bohai Oilfield has launched a water injection well pressure optimization project, focusing on improving the efficiency and quality of water injection in the water injection wells, in order to achieve the optimal water injection plan. In practical work, P Oilfield continues to promote the development of water injection well pressure optimization projects, emphasizing practical exploration and continuous optimization of work plans. However, during the project implementation process, there were some problems, one of which was that the statistics of cumulative injection volume were not scientific enough, resulting in a more comprehensive and accurate presentation of the actual results of pressure optimization work. In the context of continuous improvement work, after careful analysis and research, P Oilfield has decided to optimize the cumulative injection rate algorithm to guide the oilfield’s water injection work in a more refined way, ensuring sufficient and good water injection, and enhancing the oilfield’s production efficiency and comprehensive competitiveness.
文摘Cyclic pressure pulsing with nitrogen is studied for hydraulically fractured wells in depleted reservoirs.A compositional simulation model is constructed to represent the hydraulic fractures through local-grid refinement.The process is analyzed from both operational and reservoir/hydraulic-fracture perspectives.Key sensitivity parameters for the operational component are chosen as the injection rate,lengths of injection and soaking periods and the economic rate limit to shut-in the well.For the reservoir/hydraulic fracturing components,reservoir permeability,hydraulic fracture permeability,effective thickness and half-length are used.These parameters are varied at five levels.A full-factorial experimental design is utilized to run 1250 cases.The study shows that within the ranges studied,the gas-injection process is applied successfully for a 20-year project period with net present values based on the incremental recoveries greater than zero.It is observed that the cycle rate limit,injection and soaking periods must be optimized to maximize the efficiency.The simulation results are used to develop a neural network based proxy model that can be used as a screening tool for the process.The proxy model is validated with blind-cases with a correlation coefficient of 0.96.
文摘A novel model for dynamic temperature distribution in heavy oil reservoirs is derived from the principle of energy conservation.A difference equation of the model is firstly separated into radial and axial difference equations and then integrated.Taking into account the coupling of temperature and pressure in the reservoir and wellbore,models for calculating distributions of the reservoir temperature,reservoir pressure,and water saturation are also developed.The steam injected into the wellbore has a more significant effect on reservoir pressure than on reservoir temperature.Calculation results indicate that the reservoir temperature and pressure decrease exponentially with increasing distance from the horizontal wellbore.The radial variation range of the pressure field induced by steam is twice as wide as that of the temperature field,and both variation ranges decrease from the wellbore heel to the toe.Variation of water saturation induced by steam is similar to the temperature and pressure fields.The radial variation ranges of the reservoir temperature and pressure increase with steam injection time,but rate of increase diminishes gradually.
文摘为了解决高压欠注水井降压增注中面临的难题,以定边油田低渗透油藏的主力区块为研究对象,研究该区块的高压注水井在线酸化增注技术。利用单步法酸液体系可以抑制二次、三次沉淀物和溶解堵塞物的特性,设计在线单步法酸化智能增注系统,通过“监控表皮系数变化情况”判断“是否对目的层段持续酸化”,确保最佳酸化效果。室内实验和现场试验结果表明:G-智能复合酸对氟化钠和氟硅酸盐产生二次沉淀的抑制性最好,单步法酸液体系选择G-智能复合酸可以更好地抑制酸反应时二次沉淀物的产生;堵塞物在酸液+助渗透剂剂T影响下的溶蚀率在73.9%~79%之间,堵塞物溶蚀率高于仅加入酸液的,单步法酸液体系选择酸液+助渗透剂可提升堵塞物溶蚀率;与只注入助渗透剂T相比,注入G-智能复合酸+助渗透剂T的高压注水井的油压下降1.0~3.4 MPa,日注水量增加6.1~9.8 m 3,该技术优势显著。
