库车前陆坳陷形成大气区的烃源岩条件

SOURCE ROCKS FOR A GIANT GAS-ACCUMULATING AREA IN THE KUQA FORELAND DEPRESSION

随着勘探的深入 ,库车前陆坳陷逐渐成为我国重要的大气区。本文对其形成大气区的关键条件之一的烃源岩特征进行了深入研究。库车坳陷主要分布中 上三叠统浅湖—半深湖相泥质烃源岩和中 下侏罗统煤系烃源岩 ,具有厚度大、丰度高、类型差和成熟度高的特点。三叠 侏罗系烃源岩具有十分丰富的天然气生成量 ,天然气来源不是制约库车坳陷天然气勘探的因素 ;根据三叠 侏罗系烃源岩的类型特征和成熟度特征认为库车坳陷资源丰富、以气为主 。

The exploration revealed that the Kuqa foreland depression was becoming an important giant gas accumulating area by degrees. The article dealt mainly with source rocks which must have been one of key conditions to form a giant gas accumulating area. The shale source rocks of shallow hypabyssal lacustrine facies in age of Triassic and source rocks of coal measures in age of Jurassic were well developed in the Kuqa depression. Both of the source rocks were characterized with big thickness, high organic abundance, humic organic matter and high maturity, so as to have very huge gas generating amount. In other words, the gas source was not a factor to restrict gas exploration in the Kuqa depression. It was concluded that the resources in the Kuqa depression, mainly being natural gas, was abound and the Jurassic source rocks contributed more than that of the Triassic one in the gas generating amount.