基于枚举法的断块油藏层系重组优化设计

高含水期多油层断块油藏,纵向非均质性严重,层间动用程度差异明显,层系重组是减小层间干扰、提高中低渗储层动用程度的有效手段。文中采用枚举法,穷举出可能方案,综合考虑技术、经济两方面,筛选出采收率和经济效益都较高的重组方案。技术方面以累计产油量为评价指标,建立了多油层非活塞水驱油模型,根据B-L水驱油理论,预测各划分方案累计产油量。同时,考虑经济效益约束,采用净现值法,进行动态经济评价。以某断块油藏为例,计算结果表明:14个小层划分为2套层系,共有8 191种重组方案,采用渗流阻力级差约束后筛选,保留64种,经开发指标预测和经济效益评价,第63种为最优方案。其钻井数为2,油价3 500元/t时,其净现值为430万元。

Optimization design of strata series recombination for fault-block reservoirs based on enumeration method

In high water-cut stage,the vertical heterogeneity of the reservoirs is serious,and interlayer producing degrees are different significantly.Optimization of strata series recombination is an effeetive way to reduce interlayer interference and improve the producing degree of low permeability layers.Based on the enumeration method,all the possible strata series recombination programs were enumerated.To select the optical programs,both technical and economic aspects were considered.Based on the theory of Buckley-Leveret displacement,the cumulative oil productions of various schemes were obtained.The more the oil is produced,the more highly the program is regarded.But it's also affected by economic benefits,which were evaluated by using the net present value method.The results show that there are 8 191 programs when 14 Layers are divided into 2 strata series,and there are 64 programs left after preliminary selection by using flow resistance contrast.The left ones were evaluated with the consideration of development indices and economic benefits.With the oil price at 3 500 yuan per tonne and two drilling wells,the 63rd is the optimal program with net present value of 430×104 yuan.