Prediction Of Tight Sandstone Gas "Sweet Spots" Reservoir In J72 Well,Hangjinqi Area

In recent years,tight sandstone gas is an important part of the gradual increase in natural gas reserves,and it is the focus and difficulty of gas reservoir exploration.Hangjinqi area has low gas abundance,complicated gas-water relationship,complicated lithology and strong reservoir heterogeneity make it difficult to predict gas.In the thesis,we study the three aspects of sedimentary facies,the relationship between "sweet spots" reservoir and gas reservoirs and seismic prediction of "sweet spots" reservoir in the J72 well in Hangjinqi area based on comprehensive data of well logging,gas testing,seismic data and drilling.The lithofacies division,single-well facies analysis and connect-well profile facies analysis of nine wells were completed in the thesis.Plane facies analysis of first sand group,second sand group,third sand group in the section 1 of Shihezi Formation and Shanxi Formation.By comparing between thin layers and reservoir sections,the J72 wells were determined to be braided river delta deposit.Through researching on reservoirs in the study area,intersection analysis of the relationship between rock electrical properties,rock physical properties and productivity of nine wells were completed in this thesis,the lithology,rock electrical properties and effective reservoir thresholds in the study area were determined(porosity is 8%,permeability is 0.2mD),furthermore,the influence of study area structure and thickness of the cap rock on "sweet spots" reservoir were clarified.The gas-bearing property of the well J72 was evaluated quantitatively in the thesis.Based on the interpretation of the seismic data,the seismic attributes of the target interval was extracted.Prediction of reservoir "sweet spots" in the study area by combining the "four properties" of reservoir,sedimentary facies and post-stack seismic attribute characterization methods.Reservoir "sweet spots" are mainly distributed in the channel bars of the Shihezi Formation and the favorable area is located in ranging of wells of J72P7,J72P16 and J72P1.