非均质气藏开发难度大,边底水的侵入更增加了气藏开发的复杂程度,因此为了能够深入认清非均质边、底水气藏的水侵规律与开发效果,设计了水侵规律物理模拟装置,开展了不同渗透率级差及不同布井方式对气藏开发效果的影响,实验结果如下:无...非均质气藏开发难度大,边底水的侵入更增加了气藏开发的复杂程度,因此为了能够深入认清非均质边、底水气藏的水侵规律与开发效果,设计了水侵规律物理模拟装置,开展了不同渗透率级差及不同布井方式对气藏开发效果的影响,实验结果如下:无、边底水时,同一气藏不同区域渗透率级差越大,采出程度越高;存在边底水时,气藏采出程度随着渗透率级差的增加先增大后减小;当低渗区域渗透率为0. 01 m D时,同时在高渗区储层与低渗区储层布井,气藏整体采出程度最高,当低渗区域渗透率为0. 1 m D时,仅在低渗区储层布井,能够获得最大的无水采出程度。实验结果对非均质气藏的高效开发具有指导和实践意义。展开更多
Water alternating gas(WAG)injection is a widely used strategy for enhancing oil recovery(EOR)during gas flooding,and the mechanisms,operating parameters,and influencing factors of which have been extensively studied.H...Water alternating gas(WAG)injection is a widely used strategy for enhancing oil recovery(EOR)during gas flooding,and the mechanisms,operating parameters,and influencing factors of which have been extensively studied.However,with respect to its capacity in expanding macroscopic sweep volume under varying heterogeneities,the related results appear inadequate.In this research,three cores with different heterogeneities were used and flooded by the joint water and CO_(2) WAG,then the effects of heterogeneity on oil recovery were determined.More importantly,the cores after CO_(2) WAG injection were investigated using the nuclear magnetic resonance(NMR)technique for remaining oil distribution research,which could help us to understand the capacity of CO_(2) WAG in enlarging sweep volume at different heterogeneities.The results show that the presence of heterogeneity may largely weaken the effectiveness of water flooding,the more severe the heterogeneity,the worse the water flooding.The WAG injection of CO_(2) performs well in EOR after water flooding for all the cores with different heterogeneities;however,it could barely form a complete or full sweep throughout the low-permeability region,and un-swept bypassed regions remain.The homogeneous core is better developed by the injection of the joint water and CO_(2) WAG than the heterogeneous and fractured cases.展开更多
CBM has been recognized as a significant natural gas resource for a long time. Recently, CO_2 sequestration in coalbeds for ECBM has been attracting growing attention because of greater concerns about the effects of g...CBM has been recognized as a significant natural gas resource for a long time. Recently, CO_2 sequestration in coalbeds for ECBM has been attracting growing attention because of greater concerns about the effects of greenhouse gases and the emerging commercial significance of CBM. Reservoir-simulation technology,as a useful tool of reservoir development, has the capability to provide us with an economic means to solve complex reservoir-engineering problems with efficiency. The pore structure of coal is highly heterogeneous, and the heterogeneity of the pores depends on the coal type and rank.展开更多
In this work, the unified fracture design （UFD） is extended for the first time to the fractured horizontal wells in heterogeneous closed box-shaped tight gas reservoirs. Utilizing the direct boundary element method ...In this work, the unified fracture design （UFD） is extended for the first time to the fractured horizontal wells in heterogeneous closed box-shaped tight gas reservoirs. Utilizing the direct boundary element method and influence function, the dimensionless fracture productivity index is obtained and expressed in the function of proppant volume and fracture geometry at the pseu- do-steady state. With the iterative method, the effectively propped permeability, kfe, is corrected using the i^-situ Reynolds number, NRe. The goal of this paper is to present a new UFD extension to design the proppant volume and the optimal fracture geometry. The results show that there exists an optimal proppant volume for a certain reservoir. The small aspect ratio （yJXe） and high permeability reservoirs need short and wide fractures to diminish the non-Darcy effect. On the contrary, long and narrow fractures are required for the large aspect ratio and low permeability reservoirs. A small proppant volame is prone to creating long fractures, while a relatively large proppant volume creates wide fractures. The new extension can be used to evaluate the previous fracture parameters and design the following fracture parameters of the fractured horizontal well in heterogeneous tight gas reservoirs, with the non-Darcy effect taken into account.展开更多
文摘非均质气藏开发难度大,边底水的侵入更增加了气藏开发的复杂程度,因此为了能够深入认清非均质边、底水气藏的水侵规律与开发效果,设计了水侵规律物理模拟装置,开展了不同渗透率级差及不同布井方式对气藏开发效果的影响,实验结果如下:无、边底水时,同一气藏不同区域渗透率级差越大,采出程度越高;存在边底水时,气藏采出程度随着渗透率级差的增加先增大后减小;当低渗区域渗透率为0. 01 m D时,同时在高渗区储层与低渗区储层布井,气藏整体采出程度最高,当低渗区域渗透率为0. 1 m D时,仅在低渗区储层布井,能够获得最大的无水采出程度。实验结果对非均质气藏的高效开发具有指导和实践意义。
基金Project(KFJJ-TZ-2019-3)supported by the Open Project of Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs,ChinaProjects(51504275,51974344)supported by the National Natural Science Foundation of China。
文摘Water alternating gas(WAG)injection is a widely used strategy for enhancing oil recovery(EOR)during gas flooding,and the mechanisms,operating parameters,and influencing factors of which have been extensively studied.However,with respect to its capacity in expanding macroscopic sweep volume under varying heterogeneities,the related results appear inadequate.In this research,three cores with different heterogeneities were used and flooded by the joint water and CO_(2) WAG,then the effects of heterogeneity on oil recovery were determined.More importantly,the cores after CO_(2) WAG injection were investigated using the nuclear magnetic resonance(NMR)technique for remaining oil distribution research,which could help us to understand the capacity of CO_(2) WAG in enlarging sweep volume at different heterogeneities.The results show that the presence of heterogeneity may largely weaken the effectiveness of water flooding,the more severe the heterogeneity,the worse the water flooding.The WAG injection of CO_(2) performs well in EOR after water flooding for all the cores with different heterogeneities;however,it could barely form a complete or full sweep throughout the low-permeability region,and un-swept bypassed regions remain.The homogeneous core is better developed by the injection of the joint water and CO_(2) WAG than the heterogeneous and fractured cases.
文摘CBM has been recognized as a significant natural gas resource for a long time. Recently, CO_2 sequestration in coalbeds for ECBM has been attracting growing attention because of greater concerns about the effects of greenhouse gases and the emerging commercial significance of CBM. Reservoir-simulation technology,as a useful tool of reservoir development, has the capability to provide us with an economic means to solve complex reservoir-engineering problems with efficiency. The pore structure of coal is highly heterogeneous, and the heterogeneity of the pores depends on the coal type and rank.
基金supported by the National Natural Science Foundation of China(Grant Nos.5152540451504203&51374178)+2 种基金Open Fund(Grant No.PLN1515)of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)a special fund from China’s central government for the development of local colleges and universities-the National First-level Discipline in the Oil and Gas Engineering Project(Grant No.20150727)Scientific Research Starting Project of Southwest Petroleum University(Grant No.2014QHZ004)
文摘In this work, the unified fracture design （UFD） is extended for the first time to the fractured horizontal wells in heterogeneous closed box-shaped tight gas reservoirs. Utilizing the direct boundary element method and influence function, the dimensionless fracture productivity index is obtained and expressed in the function of proppant volume and fracture geometry at the pseu- do-steady state. With the iterative method, the effectively propped permeability, kfe, is corrected using the i^-situ Reynolds number, NRe. The goal of this paper is to present a new UFD extension to design the proppant volume and the optimal fracture geometry. The results show that there exists an optimal proppant volume for a certain reservoir. The small aspect ratio （yJXe） and high permeability reservoirs need short and wide fractures to diminish the non-Darcy effect. On the contrary, long and narrow fractures are required for the large aspect ratio and low permeability reservoirs. A small proppant volame is prone to creating long fractures, while a relatively large proppant volume creates wide fractures. The new extension can be used to evaluate the previous fracture parameters and design the following fracture parameters of the fractured horizontal well in heterogeneous tight gas reservoirs, with the non-Darcy effect taken into account.
