波斯湾盆地烃源岩特征及对油气成藏的控制

波斯湾盆地油气地质条件优越，发育古生界志留系、中生界侏罗系、白垩系3套主力烃源岩，均沉积于海侵时期的陆架内盆地相闭塞环境。志留系烃源岩为Qusaiba段热页岩，具有高GR、高有机质含量的特点，整个中东均有发育，但非连续分布，整体处于高成熟—过成熟阶段。侏罗系烃源岩为中—上侏罗统沥青质灰岩与黑色页岩，有机质丰度高，发育3个烃源灶，目前主要处于生油阶段，局部生气。白垩系烃源岩为Kazhdumi组、Balambo组及Sulaiy组泥岩，有机质丰度高，主要发育于扎格罗斯褶皱带及波斯湾西北部，处于生油阶段。烃源岩对盆地的油气成藏具有显著的控制作用，主力烃源灶的发育范围决定了其对应含油气系统内油气藏的平面分布规律，热演化程度决定了油气藏的类型。

SOURCE ROCKS IN THE PERSIAN GULF BASIN AND THEIR CONTROL OVER OIL AND GAS ACCUMULATION

Favorable oil and gas geological conditions occur in the Persian Gulf Basin. There are three main source rocks, i.e. the Silurian, Jurassic and Cretaceous. All the three sets of source rocks are deposited in an intra-shelf basin during the time of transgression. The Silurian source rock is the hot shale of the Qusaiba Member with very high GR and TOC. This hot shale, which is highly matured and/or over matured, is distributed in the whole region of Mid-East discontinuously. The Jurassic source rock is bituminous limestone and black shale of mid-upper Jurassic with high TOC. Three source kitchens are developed in Jurassic. The Jurassic source rock is still remained in oil window, with a few in gas window locally. Cretaceous source rock is the mudstone in the Kazhdumi, Balambo, and Sulaiy Formations with high TOC. It is developed mainly in the Zagros fold belt and the NW Persian Gulf, and is oil matured. According to the research made previously, source rocks have notable control on oil and gas accumulations. The distribution of source kitchens controls the spatial distribution of oil and gas accumulation in each petroleum system. The maturity of source rocks controls the type of liquid, either oil or gas.