准噶尔盆地石炭系烃源岩发育特征及分布规律OA

As oil and gas exploration in China progressively extends to deeper layers,the Carboniferous in the Junggar Basin has become a key exploration target.It has been not only found to contain abundant oil and gas resources but also confirmed as a high-quality source rock.Based on the drilling,seismic and outcrop data,combined with gravity,magnetic,and electrical data,this study investigates the development characteristics and laws of distribution of Carboniferous source rocks in the Junggar Basin,defines the hydrocarbon generation centers,and reveals the main control factors of source rock development based on the analysis of the evolution process of sedimentary paleogeographic environment,in order to deepen the understanding of the source rocks in the basin.The results of the study show that:(1)Three sets of main source rocks are developed in the Carboniferous of the Junggar Basin,including the Dishuiquan Formation(C1d)of the Lower Carboniferous,the b member of the Songkaersu Formation(C1sb)and the Shiqiantan Formation(C2sh)of the Upper Carboniferous.Its lithology is mainly composed of mudstone and tuffaceous mudstone,followed by carbonaceous mudstone,The main type of organic matter in source rocks is type Ⅲ,which is basically in a highly mature evolutionary stage,mainly producing gas.(2)The development of C1d and C2sh source rocks is mainly controlled by the sedimentary environment of marine and continental transitional facies,while the C1sb source rocks are formed during the intermittent period of volcanic eruptions,and the tuff provides favorable conditions for the development of source rocks.(3)Seven hydrocarbon source kitchens are formed in the whole basin,which are mainly distributed in the eastern sag area of the basin.The degree of confirmation of the C1d source rock is lower than that of the source rocks in C1d,C1sb and C2sh.