考虑径向流的多层油藏开发指标计算方法

Calculation method of development index of multilayer reservoir considering radial flow

海上多层非均质油藏初期多采用五点井网合注合采的方式开发,高含水期层间矛盾突出,开发指标预测难度大。针对这一问题,基于Buckley—Leverett水驱油理论,建立了考虑平面径向流的多层油藏水驱油模型,通过该模型可对各开发指标进行计算。研究结果表明:通过数值模型验证,该模型可近似反映五点井网下各油层的水驱开发动态,且与数值模拟相比,该方法计算速度更快;多层非均质油藏水驱过程中随着高渗层见水,各油层间渗流阻力的差异增大,加剧了层间矛盾,可通过采取分注分采等措施改善油藏开发效果。该研究成果对海上油田的后续高效开发与调整具有指导作用。

The five-point well pattern combined injection and production is commonly employed for development in the early stages of offshore multi-layer heterogeneous reservoirs,and the interlayer contradiction is prominent in the high water cut stage,making it difficult to predict the development index. In order to solve this problem,a multi-layer reservoir waterflooding model with the plane radial flow is established,from which the development indexes can be calculated,based on Buckley-Leverett theory. The results show that: through numerical model verification,the model can approximately reflect the water drive development performance of each reservoir under the five-point well pattern,and the calculation speed of this method is faster than that of numerical simulation;with the water breakthrough of the high permeability layer in multi-layer heterogeneous reservoirs,the difference in seepage resistance between each oil layer increases,intensifying the contradiction between layers,and the development effect of oil reservoirs can be improved by measures such as separate injection and production,etc. The research results will serve as a guide for the effective development and adjustment of offshore oilfields in the future.