准噶尔盆地西北缘湖湾区侏罗系油藏分布规律及评价

Distribution Regularities and Appraisal of Unproved Reservoirs for the Jurassic in the Northwestern Margin of Junggar Basin

利用研究区835口井资料和8口取心井岩心观察分析,采用测井相分析手段,认为湖湾区齐古组和八道湾组属于辫状河沉积,储集砂体主要为心滩和河道微相,砂体呈北东向宽带状分布,属于中高孔高渗储层;根据两种油层定量识别模型在钻遇齐古组砂体的老井中重新识别出56个油层,描述了湖湾区侏罗系油气藏空间分布规律,认为齐古组油藏主要属于岩性油藏,八道湾组属于地层油藏,为断裂台阶式成藏模式和地层不整合成藏模式;八道湾组地层油气藏具有进一步勘探潜力,齐古组岩性油藏有望实现连片分布。

The Huwan area in the northwestern margin of Junggar basin is a highly prospected area for more than 50 years. Since 1998 several new oil reservoirs have been discovered in this area including KQ-10 and KQ-109 reservoirs. In this paper, 835 old well logging data and observations of crees from 8 wells and microfacies analysis were used to finely study the reservoirs. It is concluded that the Qigu Formation and Badaowan Formation belong to the braided river sedimentation. The high permeable reservoirs mainly belong to the batture and channel sedimentary microfacies. They are distributed in a wide banded shape. By using two quantitative oil identifying models, 56 oil layers were determined from the old drilled wells for Qigu Formation. The types, controlling factors and distribution of hydrocarbon accumulations in the Badaowan Formation and Qigu Formation were summarized. It is shown that the reservoir of Qigu Formation belongs to the lithologic oil pool and the reservoir of Badaowan Formation belongs to the stratigraphic oil pool. The latter reservoir has a further exploration potential and the former reservoir may have a continuous distribution.