Geochemical Characteristics And Evaluation Of Shale Oil Resources From The Nenjiang Formation In The Southern Songliao Basin

Shale strata of Nenjiang formation in southern Songliao Basin are important source strata in Daqing Oilfield.In recent years,some of the exploration wells of Nenjiang formation have good oil and gas display.Nenjiang formation is an important formation in JiLin oilfield to increase reserves and production.Therefore,it is of great significance to determine the,amount and favorable area of shale oil resources in mudstone shale series in order to understand the distribution law of shale oil in Nenjiang formation and guide the exploration and development of shale oil in the future.In this paper,we rely on the core observation of samples in the study area and the test data of typical chemical sample analysis,complete the basic map for the study on the geochemical characteristics of shale oil,and then make a judgment on the quality and development characteristics of source rocks in the study area by combining with the organic matter logging evaluation method of source rocks.The sedimentary environment and the source of organic matter in the study area were analyzed by using biomarkers of hydrocarbon source rocks.Based on the numerical simulation results of the temperature field in the electric heating method,the in-situ modification heating simulation of low-ripeness oil in the study area is carried out.Therefore,the amount of recoverable shale oil resources in the study area can be predicted and the next step of exploration and development can be guided.In the process of research,I made the following understanding.The quality of mudstone in the first section of nenjiang formation is better than that in the second section,so it is the main contribution area of oil and gas resources.The type of organic matter in the first section of nenjiang formation is better than that in the second section.A nun is given priority to with?1 type of organic matter,mainly distributed in ChangLing sag.On the whole,the nenjiang formation is in the low mature stage,with only a small part in the mature stage.Combined with the quality evaluation of source rocks,it can be seen that source rocks with high organic matter abundance are mainly developed in the XinBei region and the Da An region,which is one of the favorable areas for shale oil enrichment.According to the characteristics of biomarker compounds,the parent material of the samples in the study area is mainly algae,mixed with a small number of terrestrial plants,the salinity of the sedimentary environment is relatively low,which is freshwater-brackish water deposition,which belongs to the sea-land communication environment.A small number of samples are deposited in transitional phase.It can be inferred from the in situ electric heating simulation that when the heat conduction is used as the heating power of 2kw,the temperature rises rapidly,and the temperature can reach more than 600 C after heating for 4 years.At 1 kw heating power,approximately 8 years will be required.When the heat conduction is used as the heating power of 2kw,the conversion of organic matter can reach about 100% after 4 years of heating,and the amount of resources in the Nen 1 member is about 24.502 billion tons.If the conversion of organic matter is close to 100% under the heating power of 1kw,it takes 8 years to heat the organic matter,and the amount of resources in the Nen 1 member can be 24.881 billion tons.