南图尔盖盆地基底特征及基岩成藏模式

在对地震、录井、测井、重力资料分析基础上,通过全三维构造精细解释、剩余重力异常综合分析等方法,对哈萨克斯坦南图尔盖盆地基底构造进行了推断解释。研究表明,该盆地具有双重基底,基底起伏十分剧烈,深大断裂发育,自西向东的4个北西—南东向展布的凹陷具有东断西超的特点。基底深度一般在1~5 km之间变化,表现为南部深度大、北部深度小的趋势,在北西向断裂系的作用下,基底局部构造大多呈北西向展布。在此研究基础上,从岩性、储集性能、生储盖配置关系及保存条件等方面进行了古潜山成藏条件分析,建立了南图尔盖盆地基岩油气成藏三种模式,突破了该区仅在古潜山风化壳含油的认识。

Characteristics and Hydrocarbon Accumulation Model of Basement in South Turgay Basin,Kazakhstan

On the basis of seismic, logging, well logging and gravity data, through the full 3D fine structure interpretation and comprehensive analysis of the residual gravity anomaly field, it is shown that South Turgay Basin consists of a double tectonic basement with relatively rolling topography and well-developing deep faults. All of 4 NW-SE trending sags distributing from west to east are characteristic of down-faulting at the eastern boundary and overlapping at the western boundary. The depth of the basement generally changes from 1km to 5km, characterized by being deep in south and shallow in north. By action of north-west fault system, most of basal local structures are in northwestward distribution. By the analysis results of conditions of hydrocarbon accumulation in buried-hills, including lithology, reservoir property, source-reservoir-cap assemblage and preservation, three models of basal hydrocarbon accumulation are established, which break through the knowledge that only the weathering crust in buried-hill is oil-bearing in this area.