新疆和什托洛盖盆地含油气评价

HYDROCARBON POTENTIAL EVALUATION IN HOXTOLGAY BASIN, XINJIANG

和什托洛盖盆地是一个海西运动期以后经多次构造运动形成的中新生代山间断陷盆地,盆地可划分为四个一级构造单元:白杨河坳陷、风台隆起、亢特能坳陷、北部断褶带.盆地内沉积了上三叠统以上地层,沉积岩厚度达5000m,具有多旋回性.中下侏罗统煤系地层是其主要的烃源层,生油门限约为2100m,于白垩纪末开始大量生烃,形成自生自储型储盖组合.因此,燕山运动中、晚期形成的圈闭将是侏罗系油气最有利的聚集场所.白杨河坳陷的生烃潜力优于亢特能坳陷,应该是该盆地最主要的勘探领域.

Hoxtolgay basin is a Mesozoic-Cenozoic intermontane fault-depression basin undergoing multiple tectonic events after Hercynian orogeny. It can be divided into four structural units : Baiyanghe depression, Fengtai uplift, Kangteneng depression and north fault-fold zone. The multi-cycle strata above the Upper Triassic are deposited, with the thickness of up to 5 000 m. Mid-Lower Jurassic coal-seam as major source rock began to generate a large amount of hydrocarbon at the end of the Cretaceous at the depth of 2 100 m, and accumulated within the sequence. Therefore the traps formed in the mid-later period of Yanshan orogeny are expected to best facilitate hydrocarbon accumulation. Baiyanghe depression should be considered as the most attractive objective of exploration in Hoxtolgay basin because of its better hydrocarbon-generation potential.