Reservoir Prediction Research Of SJ Block In The Sichuan Basin

At the end of Silurian period,the Caledonian movement uplifts the Yangtze Basinbecoming into a land,which was denuded on a large scale, until the early MiddleCarboniferous breakdown in the earth’s crust, in western hubei province to the westby transgression of the sea,which is a set of semienclosed epilittoral~strand deposit,the late carboniferous rise to a land which is denuded, and the surplus thickness isdifferent.QLX area is located in leshan~longnv temple palaeohigh east tilt slopes,and thesedimentary made repeated above the water,which is suffered from the weatheringworn and eluviating of subaerial fresh water,thus formed a suit of deep ashbrown,taupelimestone,brecciola,dolomite,carneule,solution pores dolostone.The workarea of SJ block is in the structure of QLX tectonic,south east wing hanging out at theend of downdip block. The area has the carboniferous, feixianguan, changxing groupof oil and gas production layer in vertical. Among them, the carboniferous is in thewide distribution, large thickness, which is the main production of SJ gas producingformation.From the statistics of the carboniferous of drilling wells thickness,we canrealize that the carboniferous thickness from the south to the north change little andall of the drilling in carboniferous thickness are more than50m. Reservoirgeophysical characteristics usually appears low impedance,and there is a big waveimpedance differences between seservoir and surrounding rock, we can use velocityinversion which can effectively discriminate reservoir and surrounding rock.Exploration and development practice of gas reservoir in Southeast Sichuanshows that seismic exploration technology plays a great role in gas reservoirdistribution, geometric shape description, reservoir physical parameters inversion,heterogeneity research on sedimentary facies and reservoir,high-yield enrichment zone and gas-bearing identification.The reservoir prediction results are shown: the carboniferous reservoiris widedistribution in the work area,and the reservoir development in the whole region, classI reservoir is mainly distributed in the HJ,SJ structure area and the area high parts ofthe eastern area. According to the work area of the carboniferous main features of thereservoir, with geological, logging and seismic response characteristics, we establishthe prediction ideas of the carboniferous reservoir,and think velocity is the sensitiveparameters of forecasting the carboniferous reservoirs which can use velocityinversion recognize the reservoir,then predict the carboniferous reservoir distributionand reservoir thickness,with the structure of work area,star from the oil and gas sourcerocks,reservoir conditions,migration conditions and storage conditions for analysis,theresults prove that the work area has a good condition of source,reservoir,migrationand storage,accordingly,we can provide the reference to deployed wells.