Control Effect Of Faults On Oil And Gas Transport And Storage Of The Es3 Formation In Daliuquan Area,langgu Depression

The central-north part of the Daliuquan area is the key area for oil and gas exploration in the Langgu Sag,Jizhong Depression,Bohai Bay Basin.The Es3~z and Es3~x Formations are the main target layers.The oil and gas accumulation and distribution are obviously controlled by faults.This paper is comprehensively collecting On the basis of drilling,logging,seismic and various analysis and testing data,according to seismic data,the development and activity characteristics of faults in the Es3~z and Es3~x Formations in the central-north part of the Daliuquan area are determined,the fault systems are divided,and the oil-source faults are determined.Based on the fault activity rate,the source rock formation pressure coefficient,the thickness of the sand body within the source and the section convex ridge scale index in the Es3~z and Es3~x Formations in the central-north part of the Daliuquan area,the oil and gas transport capacity of the oil source fault is evaluated.Based on drilling and seismic data,the vertical sealing of faults is evaluated by determining the thickness of mudstone cap on the top of the Es3~z and Es3~x Formations in the central-north part of the Daliuquan area.Use drilling and seismic data to determine the shale content of the fault rocks in the Es3~z and Es3~xFormations in the central-north part of the Daliuquan area,evaluate the lateral sealability of the faults.Finally,combined with the types and distribution rules of oil and gas reservoirs in the Es3~z and Es3~x Formation in the central-north part of the Daliuquan area,the controlling effect of faults on oil and gas transport and storage in the Es3~z and Es3~x Formation in the central-north part of the Daliuquan area is studied.The specific research results are as follows:(1)The oil source faults in the Es3~z and Es3~x Formation in the central-north part of the Daliuquan area are mainly type IV and type V faults,which are mainly distributed in the central area,with a small amount in the northeastern area.The oil source faults in the central and southern regions have relatively strong oil and gas transport capacity,while the oil source faults in the west,northeast and northern areas have relatively weak oil and gas transport capacity.(2)The vertical sealing area of fault in the top of the Es3~x Formation mudstone caprock are mainly distributed in the southern and northern regions of the central-north part of the Daliuquan area.The vertical sealing areas of fault in the mudstone caprock at the top of the Es3~z Formation are mainly distributed in the northern part and some parts of the northeast of the central-north part of the Daliuquan area.(3)The lateral sealing area of faults in the Es3~z Formation are mainly distributed in the eastern part of the central-north part of the Daliuquan area,and a little in the southwestern part.The lateral sealing area of faults in the Es3~x Formation are mainly distributed in the eastern part,and a little in the middle part.(4)The oil and gas reservoirs in the Es3~z and Es3~x Formations in the central-north part of the Daliuquan area are mainly fault reservoirs.The oil and gas distribution in the Es3z Formation is more than that in the Es3~x Formation,and the oil and gas in the plane are mainly distributed in the middle,southwest and northeast areas.(5)The transport and storage of oil and gas in the Es3~z and Es3~x Formations are mainly affected by faults in the north of the central-north part of Daliuquan area in the following three aspects:(1)The vertical sealing distribution of faults controls the distribution of oil and gas transport and storage;(2)The lateral sealing distribution of faults controls the plane distribution of hydrocarbon transport and storage;(3)Oil-source faults and oil-transport capacity control the location of oil-gas transport and storage and the degree of oil-gas storage.The above-mentioned research results have important reference value for guiding oil and gas exploration in the Es3~z and Es3~x Formations are mainly affected by faults in the north of the central-north part of Daliuquan area.