藏北措勤盆地油气生成特征

Features of Hydrocarbon Sources of Cuoqin Basin in Northern Tibet.

根据藏北措勤盆地的沉积、构造、地球化学特点，分析了不同烃源岩的油气生成特征，综合评价认为：沉积、构造的演化控制了烃源岩的发育与空间展布。上、下古生界主要为碳酸盐烃源岩，热演化程度高，以生气为主；三叠系、侏罗系烃源岩不发育，生烃潜力有限；下白垩统发育碳酸盐烃源岩和泥质烃源岩，热演化程度适中，为措勤盆地的主力烃源岩。生烃潜力较大。措勤盆地东北部为最有利的油气勘探远景区。

According to the sedimentation, structure and geochemistry of Cuoqin basin in northern Tibet, an analy-sis of characteristics of generating oil and gas from varied hydrocarbon source rocks is made. And a comprehensive e- valuation permits to believe that it was sedimentary and structural evolution that controlled the development and spatial distribution of its hydrocarbon source rocks. The carbonate source rock with high thermal evolution and usual generation of gas is mostly located in Upper and Lower Paleozoic systems; undeveloped and limited source potential is found in Tri-assic and Jurassic; whereas in Lower Cretaceous presence of carbonate and muddy source rocks, with moderate thermal evolution and better source potential, provide major hydrocarbon source rocks in Cuoqin basin, the northeastern part of which will be the most favorable prospective area for finding oil and gas.