Analysis Of Potential Resources And Identification Of Deep High Quality Source Rocks In Dehui Fault Depression Of South Songliao Basin

This paper is based on the research project of Jilin oil field.The research scope is the deep layer of Dehui fault depression in the south of Songliao basin.The main purpose of the study is to know clearly the distribution of effective hydrocarbon source rocks in the second member of Yingcheng,Shahe,Huoshiling group firstly,then to carry out the evaluation of the hydrocarbon source rock abundance,type and maturity.Meanwhile evaluating the hydrocarbon source rocks is based on the simulation of depositional and burial history,thermal history and combined with the hydrocarbon generation simulation experiment results and the use of chemical kinetics method.Total completion of the work for the study area is as following:analysis of geological chemical indicators,geological chemical evaluation of single well logging,quantitative simulation of hydrocarbon generation from source rocks,gas source correlation and inversion of hydrocarbon source rocks.The main achievements are as follows:1)I have evaluated the abundance,type and maturity of the hydrocarbon source rocks in the deep Dehui fault depression,and qualitatively evaluated the hydrocarbon generating potential.2)Inversed the distribution of source rocks and high quality source rocks in the deep fault depression of Dehui,in the second member of Yingcheng Formation total mudstone area is 680 km~2,high quality source rocks area is about 370 km~2;in the first member of Yingcheng Formation total mudstone area is 850km~2,high quality source rocks area is around 200 km~2;Shahe group total mudstone area is 920 km~2,high quality source rocks area is around 680 km~2;in the third member of Huoshiling Formation total mudstone area is 990 km~2,high quality source rocks area is about 510 km~2;in the second member of Huoshiling Formation total mudstone area is 775 km~2,high quality source rocks area is around 400 km~2;in the first member of Huoshiling Formation total mudstone area is 540 km~2,high quality source rocks area is around195 km~2.3)The establishment of the regional hydrocarbon production rate plate based on the hydrocarbon generation simulation experiment,the simulation of depositional and burial history,thermal history.Then the hydrocarbon generation period of the source rocks is defined by the results of the thermal evolution history of organic matter.4)I calculated the deep hydrocarbon generating quantity of Dehui fault depression in the south of Songliao basin by basin simulation software that is based on the established hydrocarbon producing rate plate,thickness of the sets of source rocks,organic carbon distribution characteristics.The calculation result is 8.8 thousand billion m~3.The resource quantity of each layer in the Dehui fault depression is obtained by the migration and accumulation coefficient and the hydrocarbon generating amount.The resource quantity of Yingcheng group is 28.3 billion m~3;Shahe group is 62.6 billion m~3;Huoshiling group is 59.5 billion m~3.In total,the resource quantity is 150.4 billion m~3.5)Based on the natural gas methane carbon isotope,gas component content and light hydrocarbon fingerprint data of mudstone/gas samples,I finished the comparison between natural gas type and gas source in Dehui fault depression,and defined the main gas source in this area.