应力敏感条件下合理井底流压的判定研究

针对低渗透应力敏感性油藏，生产压差过大后会造成近井地带岩石破碎，从而导致渗透率下降，进而影响油井产能问题，为使低渗透油藏能够得到合理高效开发，本文介绍了渗透率变异系数的计算方法，并推导出考虑应力敏感对储层造成伤害情况下，采油指数和生产压差之间的关系模型，该模型可判定出最大采油指数所对应的流压就是合理井底流压。现场实例计算验证了模型的正确性并分析了渗透率变异系数对合理井底流压影响。指出渗透率变异系数越大，最大采油指数也越低，随井底流压的继续减小而降低的幅度也越大，最大采油指数所对应合理井底流压就越大。

Stydy on reasonable bottom-hole flowing pressure under the condition of stress sensitivity

For stress sensitivity of low-permeability wells, production pressure is too large will result to near wellbore rock breaking, and cause the permeability decreasing, thereby affect the well productivity. The calculation of Permeability variation factors is introduced in this paper , a relational model between productivity index and production pressure in the view of rock stress sensitivity is also derived. The flow pressure corresponded to the maximum productivity index can be determined the reasonable bottomhole pressure by the relational model. Field example shows that full consideration of the stress sensitivity of low permeability reservoir for the determination of reasonable well flowing bottom-hole pressure is important. The greater the permeability variation factor, the lower the maximum productivity index. Continue with the bottom-hole pressure decrease ,there is greater reduction of maximum productivity index. The maximum productivity index corresponding to the greatest reasonable bottom-hole flowing pressure.