Abstract:

The western Mahu Slope is located on Mahu Sag in the vicinity of northwest margin fault belt of Jungger Basin and has the favorable hydrocarbon accumulation conditions and rich oil and gas resources.But there are a low degree of exploration and relatively poor reservoir quality in this area.The depth of the prospecting target zones typically exceeds three kilometers.The structural traps are not well-developed there,but the composite traps such as lithological traps and stratigraphical traps are favorably developed. In the light of the geological characteristics of this region,the effective reservoir predication method is mainly favorable to estimate the reserves of the slope area.The total oil and gas resources are 494 million tons and 52.9 billion cubic meters respectively.The analysis of hydrocarbon accumulation conditions shows that the exploration in the Permian and Triassic formations in the western Mahu Slope should aim at the composite areas where unconformable surface and fan were developed,while the exploration in the Jurassic formation is to make a search for the structural slope break.

Key words: Jungger Basin, Mahu Sag, effective reservoir predication method, hydrocarbon resources, lithological and stratigraphical traps, exploration potential

摘要：

玛湖西斜坡位于准噶尔盆地玛湖凹陷内紧邻西北缘断裂带,成藏条件有利,油气资源丰富.但是,其探明程度低,勘探目的层深度一般超过3000m,储层质量相对较差.虽然构造圈闭不发育,但却是岩性、地层等复合圈闭的有利发育区.针对该区的地质特点,主要利用有效储层预测法估算了斜坡区资源量(油、气资源总量分别为4.94×10⁸t和529×10⁸m³).结合成藏条件的分析,指出了下步西斜坡区在二叠系和三叠系的勘探方向是不整合面与扇体发育的复合部位,侏罗系的勘探目标主要是寻找构造坡折带.

关键词: 准噶尔盆地, 玛湖凹陷, 有效储层预测, 油气资源量, 岩性地层圈闭, 勘探潜力