Petroleum Geology Evaluation Of J₃-K₁ Layers In Sanjiang Basin

Sanjiang basin is located in heilongjiang province in northeast China,covers an area of about 33730 km2,including two depressions Suibin depression and Qianjin depression.The early stage of the sanjiang basin exploration degree is low,as oil and gas exploration prospect area,exploration significance is still significant.This topic using existing data,combining with the field reconnaissance and new drilling well data,the comprehensive contrast east sanjiang and west sanjiang in strata,sedimentary and geochemical characteristics,it is of great significanceto further reveal the oil and gas distribution of sanjiang area.Based on the theories of sedimentology oil and gas geochemical and oil and gas geology,this paper combine the existing data,The thesis use of oil and gas geology,sedimentology,geochemistry of oil and gas and other knowledge,a comprehensive analysis of the test data,combined with the indoor and outdoor research exploration,multi dimension,and from the combination of multi-disciplinary methods,well logging,seismic,geological and geochemical theories;Focus ongeochemical methods to analyze the geochemical characteristics of the study area,oil product condition of the hydrocarbon source rock,comparison and analysis of different groups and different areas in the hydrocarbon generation ability of sanjiang region;Based on the analysis of single well sedimentary facies,the facies and seismic facies,differentiate the types of sedimentary facies of the Sanjiang region,based on the well profile,research the surface distribution law of sedimentary facies in Sanjiang area.Comprehensive evaluation of the reservoir characteristics of the Sanjiang area,and puts forward the favorable exploration areas.Comprehensive result display:The J3-K1 layer of Sanjiang area mainly developed delta facies,lacustrine facies,marine-terrigenous facies and Marine facies.Depositional setting of Dongrong Formation,Chengzihe Formation,Muling Formation transition from lake delta sedimentary environment to shore and shallow lake sedimentaryenvironment and tomarine-terrigenous sedimentary environment,develop half deep lake sedimentary facies in some area.Uper Jurassic-lower cretaceous in Sanjiang basin,the organic geochemical index of rich organic matter dark mud is better.About Organic abundance,the sample TOC average in Suibin depression is 1.68%,up Jurassic TOC average was 1.96%,lower cretaceous samples of all the TOC average of 1.61%.And about Organic matter types,the result show that the source rock of Chengzihe Formation,Muling Formation is typeⅡ.To maturity of organic matter,the Ro of Chengzihe Formation,Muling Formation is generally greater than 0.7%,hydrocarbon source rocks has reached its mature stage,Comprehensive think the lower cretaceous in Suibin depression have possess the condition to generated oil and gas.The main reservoir of Suibin depression are Muling Formation,Chengzihe Formation of lower cretaceous,sandstone and volcanic clastic rock of Dongrong Formation of upper Jurassic.Sandstone reservoir belong to the low permeability sandstone reservoir,the cover layer is well developed in Suibin depression,maily about argillaceous rock.Through high-quality hydrocarbon source rocks and favorable reservoir development zone of composite,select the advantageous target zone of Suibin depression.