By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and develop...By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins.展开更多
Laboratory experiments,numerical simulations and fracturing technology were combined to address the problems in shale oil recovery by CO_(2)injection.The laboratory experiments were conducted to investigate the displa...Laboratory experiments,numerical simulations and fracturing technology were combined to address the problems in shale oil recovery by CO_(2)injection.The laboratory experiments were conducted to investigate the displacement mechanisms of shale oil extraction by CO_(2)injection,and the influences of CO_(2)pre-pad on shale mechanical properties.Numerical simulations were performed about influences of CO_(2)pre-pad fracturing and puff-n-huff for energy replenishment on the recovery efficiency.The findings obtained were applied to the field tests of CO_(2)pre-pad fracturing and single well puff-n-huff.The results show that the efficiency of CO_(2)puff-n-huff is affected by micro-and nano-scale effect,kerogen,adsorbed oil and so on,and a longer soaking time in a reasonable range leads to a higher exploitation degree of shale oil.In the"injection+soaking"stage,the exploitation degree of heavy hydrocarbons is enhanced by CO_(2)through its effects of solubility-diffusion and mass-transfer.In the"huff"stage,crude oil in large pores is displaced by CO_(2)to surrounding larger pores or bedding fractures and finally flows to the production well.The injection of CO_(2)pre-pad is conducive to keeping the rock brittle and reducing the fracture breakdown pressure,and the CO_(2)is liable to filter along the bedding surface,thereby creating a more complex fracture.Increasing the volume of CO_(2)pre-pad can improve the energizing effect,and enhance the replenishment of formation energy.Moreover,the oil recovery is more enhanced by CO_(2)huff-n-puff with the lower shale matrix permeability,the lower formation pressure,and the larger heavy hydrocarbon content.The field tests demonstrate a good performance with the pressure maintained well after CO_(2)pre-pad fracturing,the formation energy replenished effectively after CO_(2)huff-n-puff in a single well,and the well productivity improved.展开更多
An optimization method of fracturing fluid volume strength was introduced taking well X-1 in Biyang Sag of Nanxiang Basin as an example.The characteristic curves of capillary pressure and relative permeability were ob...An optimization method of fracturing fluid volume strength was introduced taking well X-1 in Biyang Sag of Nanxiang Basin as an example.The characteristic curves of capillary pressure and relative permeability were obtained from history matching between forced imbibition experimental data and core-scale reservoir simulation results and taken into a large scale reservoir model to mimic the forced imbibition behavior during the well shut-in period after fracturing.The optimization of the stimulated reservoir volume(SRV)fracturing fluid volume strength should meet the requirements of estimated ultimate recovery(EUR),increased oil recovery by forced imbibition and enhancement of formation pressure and the fluid volume strength of fracturing fluid should be controlled around a critical value to avoid either insufficiency of imbibition displacement caused by insufficient fluid amount or increase of costs and potential formation damage caused by excessive fluid amount.Reservoir simulation results showed that SRV fracturing fluid volume strength positively correlated with single-well EUR and an optimal fluid volume strength existed,above which the single-well EUR increase rate kept decreasing.An optimized increase of SRV fracturing fluid volume and shut-in time would effectively increase the formation pressure and enhance well production.Field test results of well X-1 proved the practicality of established optimization method of SRV fracturing fluid volume strength on significant enhancement of shale oil well production.展开更多
基金Supported by the Strategic Research and Technical Consultation Project of Sinopec Science and Technology CommissionSinopec Major Science and Technology Project(P22037)。
文摘By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins.
基金Supported by Basic and Forward-Looking Project of the Science and Technology Department of SINOPEC(P22213-4)。
文摘Laboratory experiments,numerical simulations and fracturing technology were combined to address the problems in shale oil recovery by CO_(2)injection.The laboratory experiments were conducted to investigate the displacement mechanisms of shale oil extraction by CO_(2)injection,and the influences of CO_(2)pre-pad on shale mechanical properties.Numerical simulations were performed about influences of CO_(2)pre-pad fracturing and puff-n-huff for energy replenishment on the recovery efficiency.The findings obtained were applied to the field tests of CO_(2)pre-pad fracturing and single well puff-n-huff.The results show that the efficiency of CO_(2)puff-n-huff is affected by micro-and nano-scale effect,kerogen,adsorbed oil and so on,and a longer soaking time in a reasonable range leads to a higher exploitation degree of shale oil.In the"injection+soaking"stage,the exploitation degree of heavy hydrocarbons is enhanced by CO_(2)through its effects of solubility-diffusion and mass-transfer.In the"huff"stage,crude oil in large pores is displaced by CO_(2)to surrounding larger pores or bedding fractures and finally flows to the production well.The injection of CO_(2)pre-pad is conducive to keeping the rock brittle and reducing the fracture breakdown pressure,and the CO_(2)is liable to filter along the bedding surface,thereby creating a more complex fracture.Increasing the volume of CO_(2)pre-pad can improve the energizing effect,and enhance the replenishment of formation energy.Moreover,the oil recovery is more enhanced by CO_(2)huff-n-puff with the lower shale matrix permeability,the lower formation pressure,and the larger heavy hydrocarbon content.The field tests demonstrate a good performance with the pressure maintained well after CO_(2)pre-pad fracturing,the formation energy replenished effectively after CO_(2)huff-n-puff in a single well,and the well productivity improved.
文摘An optimization method of fracturing fluid volume strength was introduced taking well X-1 in Biyang Sag of Nanxiang Basin as an example.The characteristic curves of capillary pressure and relative permeability were obtained from history matching between forced imbibition experimental data and core-scale reservoir simulation results and taken into a large scale reservoir model to mimic the forced imbibition behavior during the well shut-in period after fracturing.The optimization of the stimulated reservoir volume(SRV)fracturing fluid volume strength should meet the requirements of estimated ultimate recovery(EUR),increased oil recovery by forced imbibition and enhancement of formation pressure and the fluid volume strength of fracturing fluid should be controlled around a critical value to avoid either insufficiency of imbibition displacement caused by insufficient fluid amount or increase of costs and potential formation damage caused by excessive fluid amount.Reservoir simulation results showed that SRV fracturing fluid volume strength positively correlated with single-well EUR and an optimal fluid volume strength existed,above which the single-well EUR increase rate kept decreasing.An optimized increase of SRV fracturing fluid volume and shut-in time would effectively increase the formation pressure and enhance well production.Field test results of well X-1 proved the practicality of established optimization method of SRV fracturing fluid volume strength on significant enhancement of shale oil well production.
