水下分流河道岔口剩余油富集特征——以濮城油田南区沙二下为例

The enrichment of remaining oils in underwater distributary channel crotches——A case study of the lower Sha 2 reservoir in southern Pucheng oilfield

国内老油田经过长期注水开发后大部分已进入高含水开发后期,大量剩余油受储层强非均质性的影响富集在某些区域,形成的剩余油类型复杂多样。本文主要针对湖泊三角洲前缘水下分流河道岔口这一剩余油富集有利区进行研究,结合濮城油田南区沙二下油藏实践开发效果,研究分析出河道岔口的剩余油富集特征:(1)砂体厚度相对较大,沿分支河道两侧呈"中间薄、两边厚"延伸;(2)河道岔口砂体内发育薄夹层,延展范围较短;(3)河道岔口累积水油比越小,剩余油富集程度相对越高。

Most domestic mature oilfields have stepped into the later development period with super-high water-cut, bringing up complicated and various remaining oil, which were enriched in some potential regions because of strong reservoir heterogeneity. The research focus on remaining oil enrichment characteristic in channel fork, based on distributary channel fork of Lake Delta front, which are the potential regions, combined with development effect of Pucheng oilfield south district Sha 2. The result shows that,(1)Sand thickness is quite big and spread along the sides of distributary channel with characters of thick in the middle and thin in the both sides.(2)Short laps grow in channel fork sand with a short extension.(3)The smaller the cumulative water-oil ratio in channel fork, the higher potential of remaining oil.