Study On Reservoir Characteristics And Trial Production Plan Of Shaximiao Formation Gas Reservoir In QL Block

The Shaximiao Formation gas reservoir in QL block of Sichuan Basin is vertically superimposed by multi-stage river channels,which the internal pore structure of the reservoir is complex,and it is difficult to determine the pore throat configuration and fluid seepage mechanism.The production dynamic characteristics of channel sandbodies in different structural positions and different periods are quite different.Therefore,through gas reservoir evaluation,we can find out the reservoir characteristics and reserve scale,carry out the analysis of production performance characteristics and the study of production test scheme,and clarify the performance characteristics of production wells.It is of great significance for the next development to establish a targeted channel sand group classification and evaluation,well design and production allocation method.In this paper,through the study of reservoir characteristics and the evaluation of gas reservoir reserves,the lithology,physical properties,micro pore structure characteristics,sedimentary facies and reservoir characteristics and distribution rules of the study area are defined.The physical property lower limit of tight sandstone reservoir is determined,and the reasonable reserve parameters are selected to calculate the geological reserves.Through the analysis of testing,production situation and dynamic characteristics of the same layer in the similar adjacent area,according to the data of gas reservoir test wells,the reservoir productivity characteristics.main control factors and seepage characteristics are studied,.On the basis of pre production test well analysis and fine interpretation of seismic data,the seismic response mode of high-quality reservoir and the classification and evaluation standard of channel sand body are established;and the deployment mode of horizontal wells is determined through the design of production test wells and the comparative study of different well types.through the production allocation study of production test wells,the geological model of single well production test is established,and the production allocation research of different well types and wells is carried out while the numerical simulation method is used to predict the production.The results obtained in the research process are as follows:(1)the productivity simulation method,the minimum flow throat radius method and the analogy method are used to determine the lower limit of porosity,and the analogy method and the hole saturation method are used to determine the lower limit of saturation;(2)the dynamic characteristics of production test wells are analyzed,the channel sand body is classified and evaluated,and it is clear that the sand fracturing measures,the thickness of class I+II reservoirs and the gas rich degree of reservoirs are the main control factors affecting the productivity;(3)using 3D seismic data to establish high-yield well model of tight sandstone reservoir and track real drilling;(4)establishing the relationship between well trajectory and principal stress direction and putting forward the deployment mode of cluster well group development and horizontal well type.The research results show that: according to the reservoir characteristics analysis and production test scheme research in the production test area,a set of methods for tight sandstone gas reservoir characteristics analysis,gas reservoir reserves and production test evaluation are established,which guides the design and evaluation of production test scheme of Shaximiao Formation gas reservoir in QL block.