低渗透油藏压裂定向井非线性渗流模型产能计算

为了精确计算压裂定向井产能,针对压裂定向井采用拟启动压力梯度模型不能准确计算产能的问题,开展了根据启动压力梯度实验和边界层实验,得到非线性渗流模型,再通过保角变换建立压裂定向井达西模型、拟启动压力梯度模型、非线性渗流模型产能公式,计算压裂定向井达西、拟启动压力梯度、非线性渗流模型产能并与真实油井产能进行对比及产能敏感性...

Productivity calculation of nonlinear seepage model for fractured directional wells in low permeability reservoirs

In order to accurately calculate the productivity of fractured directional wells,aiming at the problem that the pseudo start-up pressure gradient model can not accurately calculate the productivity of fractured directional wells,the nonlinear seepage model is obtained according to the start-up pressure gradient experiment and boundary layer experiment,and then the productivity formulas of Darcy model,pseudo start-up pressure gradient model and nonlinear seepage model of fractured directional wells are established by conformal transformation.The research work of calculating Darcy,pseudo start-up pressure gradient,nonlinear percolation model productivity of fractured directional well and comparing with real oil well productivity and productivity sensitivity analysis.The results show that:under the same production pressure difference,the average error between Darcy model,pseudo start-up pressure gradient model and nonlinear seepage model and actual production capacity is 56.14%,13.72%and 5.11%respectively,and the nonlinear seepage model is more accurate;The fracture half length and well deviation angle are directly proportional to productivity,and the stress sensitivity coefficient is inversely proportional to productivity.The above results have certain guiding significance for productivity calculation of fractured directional wells in low permeability reservoirs.