The Upper Paleozoic in the north part of Tianhuan depression in the Ordos Basin,NW China has lower hydrocarbon generation intensity and complex gas-water relationship,the main factors controlling the formation of tigh...The Upper Paleozoic in the north part of Tianhuan depression in the Ordos Basin,NW China has lower hydrocarbon generation intensity and complex gas-water relationship,the main factors controlling the formation of tight sandstone gas and the distribution of tight sandstone gas in the low hydrocarbon generation intensity area are studied.Through two-dimensional physical simulation experiment of hydrocarbon accumulation,analysis of reservoir micro-pore-throat hydrocarbon system and dissection of typical gas reservoirs,the evaluation models of gas injection pressure,reservoir physical property,and gas generation threshold were established to determine the features of tight gas reservoirs in low hydrocarbon intensity area:(1)at the burial depth of less than 3 000 m,the hydrocarbon generation intensity ofis high enough to maintain effective charging;(2)tight sandstone in large scale occurrence is conducive to accumulation of tight gas;(3)differences in reservoir physical property control the distribution of gas pool,for the channel sandstone reservoirs,ones with better physical properties generally concentrate in the middle of sandstone zone and local structural highs;ones with poor physical properties have low gas content generally.Based on the dissection of the gas reservoir in the north Tianhuan depression,the formation of tight gas reservoirs in low hydrocarbon generating intensity area are characterized by"long term continuous charging under hydrocarbon generation pressure,gas accumulation in large scale tight sandstone,pool control by difference in reservoir physical property,and local sweet spot",and the tight gas pools are distributed in discontinuous"sheets"on the plane.This understanding has been proved by expanding exploration of tight sandstone gas in the north Tianhuan depression.展开更多
Based on the latest conventional–unconventional oil and gas databases and relevant reports,the distribution features of global tight oil were analyzed.A classification scheme of tight oil plays is proposed based on d...Based on the latest conventional–unconventional oil and gas databases and relevant reports,the distribution features of global tight oil were analyzed.A classification scheme of tight oil plays is proposed based on developed tight oil fields.Effective tight oil plays are defined by considering the exploiting practices of the past few years.Currently,potential tight oil areas are mainly distributed in 137 sets of shale strata in 84 basins,especially South America,North America,Russia,and North Africa.Foreland,craton,and continental rift basins dominate.In craton basins,tight oil mainly occurs in Paleozoic strata,while in continental rift basins,tight oil occurs in Paleozoic–Cenozoic strata.Tight oil mainly accumulates in the Cretaceous,Early Jurassic,Late Devonian,and Miocene,which correspond very well to six sets of globaldeveloped source rocks.Based on source–reservoir relationship,core data,and well-logging data,tight oil plays can be classified into eight types,above-source play,below-source play,beside-source play,in-source play,between-source play,in-source mud-dominated play,insource mud-subordinated play,and interbedded-source play.Specifically,between-source,interbedded-source,and in-source mud-subordinated plays are major targets for global tight oil development with high production.Incontrast,in-source mud-dominated and in-source plays are less satisfactory.展开更多
基金Supported by the China National Science and Technology Major Project(2016ZX05047)
文摘The Upper Paleozoic in the north part of Tianhuan depression in the Ordos Basin,NW China has lower hydrocarbon generation intensity and complex gas-water relationship,the main factors controlling the formation of tight sandstone gas and the distribution of tight sandstone gas in the low hydrocarbon generation intensity area are studied.Through two-dimensional physical simulation experiment of hydrocarbon accumulation,analysis of reservoir micro-pore-throat hydrocarbon system and dissection of typical gas reservoirs,the evaluation models of gas injection pressure,reservoir physical property,and gas generation threshold were established to determine the features of tight gas reservoirs in low hydrocarbon intensity area:(1)at the burial depth of less than 3 000 m,the hydrocarbon generation intensity ofis high enough to maintain effective charging;(2)tight sandstone in large scale occurrence is conducive to accumulation of tight gas;(3)differences in reservoir physical property control the distribution of gas pool,for the channel sandstone reservoirs,ones with better physical properties generally concentrate in the middle of sandstone zone and local structural highs;ones with poor physical properties have low gas content generally.Based on the dissection of the gas reservoir in the north Tianhuan depression,the formation of tight gas reservoirs in low hydrocarbon generating intensity area are characterized by"long term continuous charging under hydrocarbon generation pressure,gas accumulation in large scale tight sandstone,pool control by difference in reservoir physical property,and local sweet spot",and the tight gas pools are distributed in discontinuous"sheets"on the plane.This understanding has been proved by expanding exploration of tight sandstone gas in the north Tianhuan depression.
文摘Based on the latest conventional–unconventional oil and gas databases and relevant reports,the distribution features of global tight oil were analyzed.A classification scheme of tight oil plays is proposed based on developed tight oil fields.Effective tight oil plays are defined by considering the exploiting practices of the past few years.Currently,potential tight oil areas are mainly distributed in 137 sets of shale strata in 84 basins,especially South America,North America,Russia,and North Africa.Foreland,craton,and continental rift basins dominate.In craton basins,tight oil mainly occurs in Paleozoic strata,while in continental rift basins,tight oil occurs in Paleozoic–Cenozoic strata.Tight oil mainly accumulates in the Cretaceous,Early Jurassic,Late Devonian,and Miocene,which correspond very well to six sets of globaldeveloped source rocks.Based on source–reservoir relationship,core data,and well-logging data,tight oil plays can be classified into eight types,above-source play,below-source play,beside-source play,in-source play,between-source play,in-source mud-dominated play,insource mud-subordinated play,and interbedded-source play.Specifically,between-source,interbedded-source,and in-source mud-subordinated plays are major targets for global tight oil development with high production.Incontrast,in-source mud-dominated and in-source plays are less satisfactory.
