幂律流体稠油油藏水平井产能影响因素分析

Analysis on Influence Factors of Horizontal Well Productivity in Heavy Oil Reservoir with Power Law Fluid

随着相关技术的不断发展和成熟,水平井已成为高效开发稠油油藏的重要手段。为了合理开发和评价稠油油藏,有必要弄清楚水平井产能的影响因素。根据水平井稳态条件下的渗流特点和ворисов方法,将水平井在稠油油藏中流动的三维渗流场近似分解为内外两个二维渗流场,推导出考虑启动压力梯度和各向异性的水平井产能公式,并在此基础上研究油层厚度、水平井段长度、各向异性、启动压力梯度及幂律指数对水平井产能的影响。分析结果表明:水平井适合开采油层较薄、垂直渗透率较大的稠油油藏;对于非牛顿性较明显的油藏,降低流体的黏度能更有效地增加水平井产能。

With continuous development and maturation of relevant technologies,horizontal drillingwell has become an important means of efficient development of heavy oil reservoirs.To develop and evaluate heavy oil reservoirs rationally,it is necessary to make clear factors affecting horizontal well productivity.According to the seepage characteristics of horizontal well in steady state conditions,3D seepage field of horizontal well in heavy oil reservoir is approximately decomposed into inner and outer 2D seepage fields and derived is horizontal well productivity formula considering threshold pressure gradient and anisotropy.Studied are effects of oil layer thickness,horizontal section length,anisotropy,threshold pressure gradient and power-law index on productivity of horizontal well.The results show that horizontal drilling well is suitable for the exploitation of heavy oil reservoirs with thinner oil layers and larger vertical permeability.For obvious non-Newtonian reservoirs,decrease offluid viscositycan more effectivelyincrease productivityofhorizontal well.