Oil And Gas Exploration Potential And Target Selection Of Tight Sandstone In The Southern Part Of The Western Depression

The Western Sag of Liaohe Oilfield is a famous oil and gas depression.At present,it has entered a high maturity stage.The conventional oil and gas reservoirs in the middle and shallow layers have been basically explored,deep and tight sandstone oil and gas become the key point of next exploration.In recent years,shuang225、shuang227 wells obtain low yield gas reservoir in deep oil test,we have seen the preliminary achievements in the exploration of tight sandstone.In order to expand the exploration result,we start from three conditions for the formation of tight sandstone oil and gas,through the deep analysis of the quality of source rocks,reservoir characteristics and reservoir forming conditions,we think there is still a large amount of surplus resource.The hydrocarbon source rocks of Es3 in the study area are widely distributed,they have good organic type,high maturity and hydrocarbon generation intensity,they provide a good material basis for the formation of tight sandstone oil and gas.In addition,influenced by the provenance of the east and the west,the sand body of lake bottom fan is widely distributed in Es3.The deep reservoir has poor physical properties,but when sand body moves to the lake,it is directly contacted with hydrocarbon source rocks,forming a deep reservoir favorable combination of reservoirs and cover coat,which is conductive to pool accumulation of oil and gas in tight reservoir.Therefore,the southern part of the western depression has the exploration potential of forming tight sandstone oil and gas.In order to expand the exploration result of the tight sandstone oil and gas,we start from the type analysis of the tight sandstone oil and gas.Through the analysis of the accumulation period and the tight period of reservoir,we have made clear the mechanism and distributionof the accumulation.there are two tpyes of primary and transformation tight sandstone oil and gas.The primary tpyes are distributed in the qingshui depression and the slope area.The transformation tpyes are distributed in the surrounding positive tectonic zone of the qingshui depression.Therefore,we have carried out the evaluationg andprediction of fine reservoir,we have cleared the distributionof the reservoir.