特低渗透压敏油藏产量递减规律数值模拟

Numerical simulation research on production decline laws in particular pressure sensitive low permeability oil reservoir

对于异常高压特低渗透压敏油藏注水开发比较困难,一般采用人工压裂依靠天然能量开发。开发过程中油井产量受地层能量的衰减、压敏效应以及裂缝导流能力衰减等因素的影响。在充分考虑上述影响因素的基础上,建立了考虑压敏效应和裂缝导流能力动态衰减的流固耦合渗流数学模型,并开发了相应的软件,实现了产量递减规律的快速预测。建立了异常高压特低渗透压敏油藏的概念模型,对其产量递减规律进行了研究,结果表明:井距越小、井底压力保持水平越低、裂缝导流能力衰减得越快,地层压力下降越快,产量递减速度越快;考虑压敏效应时产量递减速度明显快于不考虑压敏效应时的情况。利用该方法对博兴洼陷梁112块产量递减规律进行拟合和预测,取得很好的效果。

Flooding is difficult in abnormal high pressure and pressure sensitive low permeability oil reservoir, so, artificial fracturing is used based on natural depletion development. During the development, the production of producers is affected by many factors, such as the attenuation of formation energy, pressure sensitive effect and the attenuation of fracture flow capacity. Based on the factors mentioned, the fluid-solid coupling mathematical model is established with the consideration of pressure sensitive effect and the dynamic attenuation of fracture flow capacity, and the relative software is developed for the fast prediction of production decline laws. The concept model for abnormal high pressure and pressure sensitive low permeability oil reservoir is built, and its production decline law is studied. The results indicate： shorter well spacing means poorer bottom hole pressure maintenance and faster attenuation of fracture flow capacity, and faster decline of formation pressure means faster production decline rate; when pressure sensitive effect is taken into account, the production decline rate is obviously faster than that without the consideration of pressure sensitive effect. This method is applied to the adaptation and prediction of production decline laws in Block Liang112 in Boxing depression, and good results are achieved.