Sedimentary Facies And Reservoir Characteristics Of Shaximiao Formation In Gongshanmiao Area,Central Sichuan

The Gongshanmiao structure is located in the northern margin of the Nanchong tectonic group in the middle sloping tectonics of the Guzhong,and the ground structure is an east-west anticline trap.The west of the structure is the slanting saddle of the Huluxi slant and the octagonal field structure.It is separated from the red flower shop,and the south of the structure is also facing the Nanchong structure,and the north is the Xingshan field.The Zhongjiang gas field in the neighboring area and the Bajiaochang area in the Sichuan Basin have obtained good industrial gas production capacity in the Shaximiao Formation.However,the current rolling exploration and development in the Gongshanmiao area has been 20 years,the overall drilling success rate is low,and oil and gas exploration has fallen into a Low valley.In the early stage,the middle and upper channel sandstone reservoirs of the Shaximiao Formation were not the main target layers.The lack of drilling test data and the lack of systematic geological research,therefore,the study of the sedimentary and reservoir characteristics of the Shaximiao Formation in the Gongshanmiao area is It is important.This paper takes the sedimentary and reservoir characteristics of the Shaximiao Formation in the Gongshanmiao area of the central Sichuan Basin as the research object,and adopts new theories and methods such as sequence stratigraphy and sedimentology,using well logging,logging,core and earthquake.Analytical data were used to analyze and study the sedimentary facies of the Shaximiao Formation in the Gongshanmiao area of Chuanzhong.Combining the field profile and logging,the Shaximiao Formation in the central Sichuan Basin was studied in detail using high-resolution sequence stratigraphy.The study shows that the Shaximiao Formation in the Gongshanmiao area of the central Sichuan Basin is characterized by lake-delta facies deposition.The reservoirs can be divided into delta front mat sand,delta front subaqueous distributary channel and delta plain distributary channel sand body.Based on the sedimentary characteristics,the petrological characteristics,physical characteristics and reservoir sand body distribution characteristics of the Shaximiao Formation are studied.The formation and distribution of the Shaximiao Formation reservoirs in the Gongshanmiao area of central Sichuan are generally controlled by lithology,sedimentary microfacies and diagenesis.The porosity of the reservoir decreases with the increase of cement content,which is an important factor affecting the change of physical properties.The underwater distributary channel and the distributary channel microfacies are the sedimentary microfacies most favorable for reservoir development.