Study On Logging Treatment Method Of Shale Mineral Composition And Brittleness

Oil and gas exploration in the Sichuan Basin and the surrounding shale formations is one of the key areas of current and future exploration.Logging technology plays an important role in shale gas exploration,but logging evaluation of shale reservoirs faces many challenges,such as complex mineral composition,and the mineral content of shale oil and gas reservoirs in different basins varies greatly;traditional conventional surveys well porosity calculation method is not applicable to shale reservoirs;resistivity method is not suitable for calculating shale oil and gas saturation;there are many factors affecting fracturing,and it is difficult to establish continuous and complete shale reservoir fracturing Sexual evaluation methods,etc.At present,the research area has not yet formed a complete,systematic and highly versatile shale gas reservoir logging evaluation technology.For the above problems,data such as logging,core(rock debris)analysis,geochemical and testing are collected.The conventional “six related logging goals” relationship analysis was carried out on shale reservoirs,and the evaluation methods and models of six-parameter parameters in the study target area were established.In the evaluation of the “six related logging goals”,the final utilization logging is performed by analyzing and evaluating the lithology,geochemical characteristics,physical properties,gas-bearing properties,electrical properties and fracture properties of the Wufeng Formation-Longmaxi Formation shale reservoir in the key well.Information processing lays the foundation for evaluating relevant parameters of shale reservoirs.In the calculation of shale reservoir porosity,the traditional conventional logging porosity calculation method is no longer applicable.It mainly uses a large number of core physical property analysis statistics combined with sensitive logging information to establish a regional logging porosity calculation method.In this reserve research area,it is preferred to calculate shale reservoir porosity using acoustic time difference,neutron and density based on empirical statistics with high computational accuracy and good operability.In the calculation of gas saturation of shale reservoirs,the reservoirs have low resistance due to factors such as high bound water content and conductive “graphitization” of pyrite or shale in the reservoir.The three methods of determining the gas saturation of non-resistivity method are compared,and the applicability of the gas saturation calculation method for low-resistance shale gas reservoir is analyzed,and the calculation of Archie formula of low-resistance reservoir is solved.The problem of reduced accuracy of gas saturation is to promote the development of logging interpretation of low-resistance shale gas reservoirs and improve the accuracy of shale gas gas content evaluation.In the evaluation of shale reservoir fractureability,combined with rock mechanics experiments and previous research results,rock mechanics parameters and ground stress analysis of shale gas reservoirs are carried out for shale gas reservoirs,and the study is applicable to the study area.The new model of fourparameter crushability evaluation introduces the shale maturity index,expands the connotation of the compressibility evaluation,and sees good results in practical applications.