| The YKL gas field with great resource potential is located in the north of Tarim Basin,Xinjiang Uygur autonomous region of China.With the study of the preliminary exploration and development,the paper is based on the theory of high resolution sequence stratigraphy,combined with the core,well logging,seismic and production dynamic data in the study area.The stratigraphic sequence division and correlation,sedimentary facies and sand distribution characteristics of the Cretaceous Aglemu Formaion in the study were studied successively.Finaly,the three-dimensional fine geological model of the gas reservoir in YKL well area was established.The modeling can provide some guidance for improving the recovery factor of gas reservoir development.The main achievements of the paper are as follows:(1)Combined with the core,well logging and seismic data,three intermediate semi-cycles(lower,middle and upper gas layers)and seven short-term cycles were identified from the bottom to the top of the Yagelim Formation in the study area.The stratigraphy sequence cycles of the whole 44 wells were diveded and compared with the principle of isochronous correlation under the guidance of the principle of high resolution sequnence stratigraphy.Finally,the isochronous stratigraphy framework of the YKL well region Agliemu Formation was established.(2)The sedimentary markers of the Yagelim Formation such as lithology,fabric characteristics,sedimentary structure,logging characteristics and sedimentary particles sizes were identified in the study area form micro and macro perspectives.The comprehensive interpertation of sedimentary facies was carried out in the single well,the litho-eletric map was established and the sedimentary environment of the fan delta front was defined in the study area.Six sedimentary facies types including underwater distributary channel,estuary dam,interdistributary bay,sheet sand,floodplain and por-fan delta were divided.Combined with the seismic amplitude map and the sand-to ground ration isoline map,the distribution characteristics of the fan delta in the study area were described,and the model of the fan delta sedimentary facies was established.(3)Sand body deposition accounts for more than 90% of the whloe strata in the study area,and the thickness of each gas fomaion is mainly distributed in the interval of 10-25 m,with the upper gas layer having the largest thickness.The sand body of the main area in the study area is thicker than the east.The partition layer was divided according to GR>90,AC<75,DEN>2.5,POR<8 with the comprehensive analysis.Mezzanine can be divided into physical mezzanine and argillaceous mezzznine.The most mezzanine types in the study area are argillaceous,for more than 80 percent.The thickness of interlayers is mainly between 0 and 3m,which and reach up to 5.5m.(4)The three-dimensional fine geological model of YKL well region Aglium Formation was established based on the prebious geological understanding with the idea of facies-controlled modeling,including structural model,sedimentary facies model,lithofacies model,arribute model,gas-water interface model and so on.The geological reserves were calculated by the reserves calculation module.Compared with the volumetric method,the condensate gas fitting degree was 98.1%,and the condensate oil fitting degree was 89%.The coarsening model was verified by the numerical simulation,the historical gas-producing fitting degree was 99%,and the liquid-producing fitting degree was 87.5%. |
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