压敏效应对低渗透油田开发的影响

认为低渗透油田开发难度大的主要原因之一在于渗透率较低 .为弄清渗透率与压力的关系 ,以实验为基础 ,利用油田天然岩心模拟油田开发过程 ,研究压力的变化对岩心渗透率的影响 ;分析了渗透率的压力敏感性特征以及低渗透油田开发中存在的压敏效应 .指出随着开发过程的进行 ,地层压力逐渐下降 ,进而因油藏压力的降低所诱发的渗透率的压力敏感性伤害将不可避免 ,最终导致的渗透率损失对低渗透油田开发的影响是巨大的 .研究表明因压敏效应的存在 ,在井壁附近地层渗透率值只占供液边界处渗透率值的 45 %左右 ;当地层压力下降 5 MPa时 ,产量下降可达 1 3%左右 .

Effect of Pressure-sensitive Damage on the Development of Low Permeability Reservoirs

Knowing the relationship between permeability and pressure is important to scientific and reasonable development of low permeability reservoirs. On the basis of experimental research, the pressure sensitive characteristics of reservoir permeability are analysed. It is pointed that the damage of pressure sensitivity to formation permeability can not be avoided if reservoir pressure decreases gradually during development. The loss of the permeability has the unfavorable affect on the production performance. The study in the paper shows that if there is a pressure sensitive effect, the permeability near wellbore is only 45% of the permeability in drainage border; when formation pressure decreases by 5 MPa, production rate will decrease by 13%.