Drilling,seismic and logging data were used to evaluate the hydrocarbon accumulation conditions of the mound-shoal complexes in the platform margin of the fourth member of Sinian Dengying Formation in the east side of...Drilling,seismic and logging data were used to evaluate the hydrocarbon accumulation conditions of the mound-shoal complexes in the platform margin of the fourth member of Sinian Dengying Formation in the east side of the Mianzhu-Changning intracratonic rift in the Sichuan Basin.The four understandings are:(1)The platform margin belt of the Deng 4 Member can be divided into three sections,northern,middle and southern;the middle section is at the core of the Gaoshiti-Moxi paleouplift and the structural high now,while the southern and northern sections are at the slope of the paleouplift and the structural lows now;the three sections have similar development characteristics and reservoir features of platform margin mound-shoal complex.(2)In the margin of the east side of the rift,there are several faults nearly perpendicular to the platform margin belt,the faults divide the platform margin belt into rugged paleo-landform,and the high part developed platform margin mound-shoal complexes and the reservoirs are good in physical properties,while the low part developed inter-beach depression and no mound-shoal complexes,where the reservoirs are poor in physical properties.(3)The six groups of faults nearly perpendicular to the platform margin belt divide the platform margin belt into seven large mound-shoal complexes which have similar hydrocarbon accumulation conditions and accumulation evolution process and are rich in petroleum.(4)The inter shoal depressions between the mound-shoal complexes are characterized by tighter lithology,which can block the updip direction of the mounds and shoals at the lower part of the slope of the paleouplift and are favorable for the later preservation of mound-shoal gas reservoirs.This has been proved by Well Jiaotan 1 and Heshen 2 drilled successfully.The mound-shoal complexes on the platform margin of the structural slope area have a good exploration prospect.展开更多
Based on the abundant outcrops and 3 D seismic data in Yuanba and its surrounding areas in northeastern Sichuan Basin,the characteristics,main controlling factors and development regularities of reservoirs in the four...Based on the abundant outcrops and 3 D seismic data in Yuanba and its surrounding areas in northeastern Sichuan Basin,the characteristics,main controlling factors and development regularities of reservoirs in the fourth member of Sinian Dengying Formation(shortened as Deng 4 Member)were analyzed comprehensively.The results show that the reservoirs were mainly developed in microbial dolomite associated with the microbial mound and dolarenite associated with grain beach,and had intergranular dissolution pores,inter-frame dissolution pores and karst caves as main storage space.The reservoirs were large in scale and strong in heterogeneity.The analysis of the reservoir genetic mechanisms shows that the reservoirs in the fourth member of Dengying Formation were the products of karstification on mound-beach facies deposited in the second episode of Tongwan movement.The karstification had the marks of eogenetic karstification such as granophyric karst system and half-dissociation zone.The reservoirs were controlled by the sedimentary facies belt,the mound beach facies was the decisive factor in reservoir development.Further analysis indicates that the Yuanba area had a geological background of well-developed platform margin mound beach facies,so mound beach bodies can be taken as a favorable exploration target.展开更多
基金Supported by the China National Science and Technology Major Project(2016ZX05007-002)
文摘Drilling,seismic and logging data were used to evaluate the hydrocarbon accumulation conditions of the mound-shoal complexes in the platform margin of the fourth member of Sinian Dengying Formation in the east side of the Mianzhu-Changning intracratonic rift in the Sichuan Basin.The four understandings are:(1)The platform margin belt of the Deng 4 Member can be divided into three sections,northern,middle and southern;the middle section is at the core of the Gaoshiti-Moxi paleouplift and the structural high now,while the southern and northern sections are at the slope of the paleouplift and the structural lows now;the three sections have similar development characteristics and reservoir features of platform margin mound-shoal complex.(2)In the margin of the east side of the rift,there are several faults nearly perpendicular to the platform margin belt,the faults divide the platform margin belt into rugged paleo-landform,and the high part developed platform margin mound-shoal complexes and the reservoirs are good in physical properties,while the low part developed inter-beach depression and no mound-shoal complexes,where the reservoirs are poor in physical properties.(3)The six groups of faults nearly perpendicular to the platform margin belt divide the platform margin belt into seven large mound-shoal complexes which have similar hydrocarbon accumulation conditions and accumulation evolution process and are rich in petroleum.(4)The inter shoal depressions between the mound-shoal complexes are characterized by tighter lithology,which can block the updip direction of the mounds and shoals at the lower part of the slope of the paleouplift and are favorable for the later preservation of mound-shoal gas reservoirs.This has been proved by Well Jiaotan 1 and Heshen 2 drilled successfully.The mound-shoal complexes on the platform margin of the structural slope area have a good exploration prospect.
基金Supported by the China National Science and Technology Major Project(2017ZX05005-003-006)
文摘Based on the abundant outcrops and 3 D seismic data in Yuanba and its surrounding areas in northeastern Sichuan Basin,the characteristics,main controlling factors and development regularities of reservoirs in the fourth member of Sinian Dengying Formation(shortened as Deng 4 Member)were analyzed comprehensively.The results show that the reservoirs were mainly developed in microbial dolomite associated with the microbial mound and dolarenite associated with grain beach,and had intergranular dissolution pores,inter-frame dissolution pores and karst caves as main storage space.The reservoirs were large in scale and strong in heterogeneity.The analysis of the reservoir genetic mechanisms shows that the reservoirs in the fourth member of Dengying Formation were the products of karstification on mound-beach facies deposited in the second episode of Tongwan movement.The karstification had the marks of eogenetic karstification such as granophyric karst system and half-dissociation zone.The reservoirs were controlled by the sedimentary facies belt,the mound beach facies was the decisive factor in reservoir development.Further analysis indicates that the Yuanba area had a geological background of well-developed platform margin mound beach facies,so mound beach bodies can be taken as a favorable exploration target.
