Source Kitchen And Petroleum Accumulation In Errennaoer Sag,Erlian Basin

Based on a large number of source rock analyses,this paper has carefully evaluated the distribution of source kitchen in Errennaoer Sag,compared with the nature of oil and gas,and discussed the process of oil and gas from foci to reservoirs.The source rock logging geochemical evaluation was carried out on 17 key exploration wells in the Errennaoer Sag.The thickness and distribution of high-quality source rocks in different formations in Errennaoer Sag were analyzed based on logging data and geochemical analysis data,and their spatial distribution was finely characterized.The effective source rocks in Errennaoer Sag are the source rocks in K₁ba₂ and K₁ba₄.The source rocks in K₁ba₂ that contribute more to oil and gas are mainly organaic facies C source rocks,mainly developed in the southern part of the Sag,with a thickness of 20m-110m.The source rocks in K₁ba₄ are mainly organaic facies C and organaic facies D/E,mainly developed in the middle sag,with a thickness of20m-240m.The organic maturity of the source rocks in K₁ba₂ is relatively high and has entered the threshold of oil generation.Oil generation has begun.The organic maturity of K₁ba₄ is generally relatively low.According to the data of proven oil and gas reserved in Errennaoer Sag,the relationship between oil and gas reserved in Errennaoer Sag is analyzed.The effective source rocks in Errennaoer Sag are the organaic facies C source rocks of K₁bt₄ and K₁ba₂.The source rocks control the distribution of conventional oil and gas reservoirs,and most oil and gas reservoirs are distributed near the source rocks of K₁ba₂.The overall oil discharge volume of the K₁ba₂ is relatively large,ranging from 0.5 mmt/km² to 3.5 mmt/km²,and the exhaust volume is from 0.5billion m³/km² to 520 million m³/km².Generally speaking,the hydrocarbon source range of the K₁ba₂ is more important.The geological model of oil and gas migration and accumulation in Errennaoer Sag is established to analyze the oil and gas system,migration and accumulation units and forecast favorable areas.The exploration layer of K₁ba₂ should be the first choice in Errennaoer sag.