准噶尔盆地西北缘二叠系风城组储层发育特征及油气富集因素

Reservoir Characterization and Hydrocarbon Enrichment Factors of the Permian Fengcheng Formation in the Northwestern Margin of Junggar Basin

为了明确准噶尔盆地西北缘二叠系风城组储层的发育特征,分析控制油气富集的主要因素,指导下步勘探开发,通过钻井、岩心、薄片和扫描电镜等资料的观察与分析,对储层的岩石类型、储集空间、物性特征及其对油气富集的控制作用进行了研究。研究表明:研究区内二叠系风城组储层类型主要包括碎屑岩、云质岩和火山岩,储集空间主要为原生孔隙、溶孔和裂缝;碎屑岩储层整体为低—中孔隙度,平均值为7. 32%,粒内溶孔是其主要储集空间类型;云质岩储层孔隙度平均值为4. 62%,溶孔和裂缝是其主要储集空间类型;火山岩储层孔隙度平均值为2. 60%,溶孔和裂缝是其主要储集空间类型;优质储层控制了油气富集成藏,物性较好的储层含油性好。在此基础上,讨论了沉积作用、成岩作用以及构造作用对优质储层的控制作用,并预测了不同类型优质储层的空间展布。该研究对准噶尔盆地西北缘二叠系风城组储层下步勘探部署有较强指导意义。

In order to clarify the reservoir development features, main-controlling factors of hydrocarbon enrichment and the guidance for further exploration and development of the Permian Fengcheng Formation in the northwestern margin of Junggar Basin, the reservoir rock classification, reservoir space, physical properties and their effects on hydrocarbon enrichment are researched based on the drilling, core test, thin-section analysis, scanning electron microscopy and other data. Research indicates that the reservoir of Permian Fengcheng Formation can be classified as clastic, cloud and volcanic rocks, and the reservoir space mainly consists of primary pore, dissolved pore and fracture. The clastic reservoir generally possesses low-medium porosity with an average of 7.32%, and the intragranular dissolved pore dominates the reservoir space. The average porosity of cloud-rock reservoir is 4.62%, and the pore and fracture dominate the reservoir space. The average porosity of volcanic reservoir is 2.60%, and the pore and fracture dominate the reservoir space. Hydrocarbon enrichment and accumulation are dependent on the high-quality reservoir, which shows a high oil-nearing properties. Based on this understanding, the effects of sedimentation, diagenesis and tectonic action on high-quality reservoir are discussed, and the spatial distribution of different high-quality reservoirs is predicted. This research could provide certain guidance for the further hydrocarbon reservoir exploration and deployment of the Lower Permian Fengcheng Formation in the northwestern margin of Junggar Basin.