Study On The Shale Oil Enrichment Law In Xinbei Area,Southern Songliao Basin

The research firstly based on existing geological,seismic,well logging and analytical test data,using mud shale analysis methods,seismic sedimentology methods,petroleum geology methods,geochemical methods,etc.,to analyze the distribution characteristics of mudstone facies and the distribution of mudstone space.The organic geochemical characteristics of the source rocks,the characteristics of the reservoir system,the fracture and micro-fracture systems,and the systematic analysis of the shale oil accumulation conditions in the New North area.The main controlling factors of hydrocarbon accumulation are analyzed from the following aspects:organic matter abundance of source rock and Ro,effective thickness of high-quality shale,abnormal pressure,and crack characteristic system.Then determine the key evaluation parameters,conduct resource evaluation,and summarize the law of rich accumulation of mud shale oil.According to the research of this project and the previous research results,the shale with organic carbon content>2.0%and maturity of 0.5%<Ro<1.2%was defined as high quality shale.It reveals the spatial distribution and organic matter abundance of high-quality shale in Qing 1 section and Qing 2 section.Two sets of high-quality shale sections are developed in the longitudinal section of the Qing 1 section.They are located in the III and IV sand groups,the I sand group and the Qing 2 section high quality shale located in the lower V sand group.On the plane,all the high-quality shale in Qing 1 section and Qing 2 section are distributed.The high values of TOC and S1 are located in the southeastern margin of the New North.The maximum thickness of high-quality shale is also located in the southern margin of the New North.The shale pore types of the Qing 1 and Qing 2 shale have inorganic intergranular pores,intercrystalline pores,dissolved pores,organic pores and micro-cracks.The shale reservoir types are classified into 4 types,from 1 to 4,and microporous throats.The content gradually increased,the content of large pore throat gradually decreased,the content of small pore throat and mesoporous throat increased first and then decreased,the average pore throat radius and permeability gradually decreased.However,the change of porosity is more complicated,there is a certain overlap,the porosity of the four types of reservoirs is the lowest,and the porosity of the two types of reservoirs is the highest.The Qing 1 section and the Qing 2 section are mainly type 2 and type 3 reservoirs.The shale oil reservoirs can be divided into four grades according to the average pore throat radius of 10,70 and 150 nm,respectively:Grade ?,Grade ?,Grade? and Grade IV.Class ?,Class ?.The spatial distribution law of brittleness index of high quality shale in Qing 1 section and Qing 2 section is revealed.The longitudinal section of Qing 2 is higher than the section of Qing 1,and the high value on the plane is located on the west side of the study area.According to the rock composition,organic matter abundance and sedimentary structure,the shale rock facies are divided and the classification of rock facies is established.The organic-rich shale facies are mainly distributed on the east and west sides of the study area.The storage conditions,fractures and hydrocarbon generation basis are the three main controlling factors for shale oil enrichment,based on total organic carbon,vitrinite reflectance,effective thickness of high quality shale,brittleness index,porosity and shale oil.Six parameters,such as sex,constructed a preferred standard for the favorable area of mud shale oil.