LD 10-1油田不同韵律性厚油层剩余油富集规律

Enrichment Law of Remaining Oil in Different Rhythmic Thick Oil Reservoirs in LD10-1 Oilfield

随着LD10-1油田进入高含水和高采出程度的"双高"阶段,剩余油分布日益复杂,韵律性影响尤为突出,本文基于LD10-1油田的实际油藏地质特征,考虑7种不同韵律性建立厚油层模型,通过数值模拟的方法来研究剩余油的富集规律。研究发现对于不同韵律性厚油层,无论是水驱还是早期注聚,剩余油富集规律基本一致,主要富集在厚油层上部、低渗层以及靠近生产井一侧,只是早期注聚后剩余油的含量显著减少。同时,厚油层受重力作用影响较大,在注入水驱替的过程中,模型下部的原油向上运移,使得模型上部地层采收率较大,动用程度较小,再加上原始模型中存在可动水,较原始储量相比,模型上部储量上升。最后,除了复合正反韵律模型,对于其他韵律性的模型,早期注聚均能有效提高采收率,提高采收率的幅度均在10%以上,开发效果较好。

With LD10-1 Oilfield entering the "double high" stage of high water cut and high recovery degree,the distribution of remaining oil is becoming more and more complex,especially influenced by rhythm.Based on the actual geological characteristics of oil reservoirs in LD10-1 Oilfield,thick oil reservoir models are established with seven different rhythms,and the numerical simulation method is applied to study the enrichment law of remaining oil.The study finds that the enrichment law of remaining oil is basically the same for different rhythmic thick oil reservoirs whether water flooding or early polymer flooding is carried out.It is mainly concentrated at the upper part of the thick oil reservoirs,the low permeability layers and the side near the production wells,but the remaining oil after early polymer flooding significantly reduces.At the same time,thick oil reservoirs are greatly affected by gravity.During the process of water flooding,the crude oil at the lower part of the model moves upwards,which makes higher recovery and lower degree of production at the upper layer of the model,and the reserves at the upper part of the model have increased compared to the original reserves for movable water in the original model.Finally,except for the compound positive and reverse rhythmic models,other rhythmic models have higher oil recovery in early polymer flooding.The range of EOR is more than 10%,and the development effect is good.