一种快速评价底水油藏开发潜力方法

Method of the development-potential rapid evaluation for bottom-water oil reservoirs

为落实底水油藏的真实油水界面、油藏规模、剩余开发潜力,提出利用已生产水平井见水时间快速评价思路,以进一步推动开发决策。而已有的底水油藏水平井见水时间计算方法中,未考虑实际水平段的强非均质性和一定油层厚度下的重力作用,计算结果误差较大。针对该问题,以非均质条件下水平井水淹规律为基础,利用镜像反映法、稳定生产流压求得水平井纵向剖面势分布,将流体流动过程微元化并结合重力作用,得到一种较为精确的底水油藏水平井见水时间求取方法。在此基础上,建立了不同生产压差条件下见水时间与油藏厚度的定量判断图版,可以快速评价底水油藏开发潜力。该方法简单实用,计算结果与实际数据、数模计算值较为匹配,具有一定推广价值。

In order to fulfill the real oil-water interface,reservoir scale and remained development potential of bottom-water oil reservoirs,a rapid evaluation of the water breakthrough time of developed horizontal wells was proposed to promote the further development policies.However,for the exiting calculating methods of the well breakthrough time in the bottom-water oil reservoirs,the reservoir strong heterogeneity and gravity action under a certain oil-reservoir thickness in the actual horizontal interval were not considered,a larger calculation error was induced.In the light of the problem stated above,based on the waterflooded laws of the horizontal wells under the heterogeneous condition,with the help of the mirror reflecting method and stable production flow pressure,the longitudinal-profile potential distribution was obtained.Moreover,combined with the action of the gravity,the fluid flow process was made infinitesimal to get a more accurate calculating method of the water breakthrough time of the horizontal wells in the bottom-water oil reservoirs.On this basis,the quantitative judging chart board of the water breakthrough time and reservoir thickness was established under different producing pressure differentials,thus the development potential of the bottom water reservoir can be rapidly evaluated.The method is simple and practical,the calculated results are more matched with both the actual data and numerical calculations,so it possesses a certain value of the generalization.