准噶尔盆地阜康凹陷阜东斜坡齐古组储层控制因素及有利区预测

Favorable accumulation region prediction and controlling factors of hydrocarbon accumulation of the Qigu Formation in the Fudong slope,Fukang Sag,Junggar Basin

准噶尔盆地阜康凹陷阜东斜坡上侏罗统齐古组一段是主要的勘探目的层。利用多种室内分析手段,对其岩石学、储集空间以及物性特征进行分析,并总结优质储集层控制因素。在优质储集层研究的基础上,通过分析已出油钻井资料,对齐一段成藏控制因素进行研究,最终进行有利成藏区域的预测。研究表明,齐古组一段以细粒岩屑砂岩为主,成分成熟度低但结构成熟度高,储集空间主要为原生粒间孔,属于中孔中高渗型储集层。物源为储集层的发育提供物质基础,沉积相及古地貌控制了储集层的分布,压实作用和异常压力共同控制储集层的物性,胶结作用和溶蚀作用对于储集层物性影响有限。成藏控制因素主要为油气运移通道及动力,前者涉及到不整合以及断裂发育,后者主要为异常压力差,综合研究认为阜东斜坡区齐一段发育4个成藏有利区域。

As the main exploration target in the Fudong slope of the Junggar Basin,the first member of the Upper Jurassic Qigu Formation was investigated. Its lithology,reservoir pore space and physical property were analyzed in lab,and controlling factors of reservoir quality were summarized. Starting from high-quality reservoir analysis,we studied the controlling factors of hydrocarbon accumulation for the Qigu 1 Member based on oil-producing well data,which ultimately enable us to predict hydrocarbon accumulation areas. And the result shows that（ 1） lithology of the Qigu 1 Member is mainly finegrained clastic sandstone with high structural maturity and low compositional maturity,and reservoir space is mainly primary intergranular pores,forming a medium porosity reservoir with medium-high permeability;（ 2） source provenances supply materials for reservoir deposition,while sedimentary facies and palaeogeomorphology control reservoir quality distribution; both compaction and abnormal pressure determine physical properties of reservoirs,while cementation and dissolution have limited impact on reservoir property;（ 3） the controlling factors of hydrocarbon accumulation are mainly oil and gas migration channels and driven power,with the former involving unconformity and fault development and the latter mainly caused by abnormal pressure difference. In conclusion,we predict four favorable accumulation regions in the Qigu1 Member of the study area.