流体在特低渗透油藏中的渗流参数分析

Parameter Analysis of Fluid Flows in Low-Permeability Reservoirs

运用实验的方法,对由大量实验结果总结出来的规律性公式——Darcy公式进行改进。Darcy公式本身存在一定的局限性,对于常规油藏来说,用其描述渗流规律具有较好的效果。但是对于低渗、特低渗透油藏来说,其渗流规律与常规油藏有着较大的差异。仅考虑启动压力的影响,对Darcy公式进行改进,改进后的公式仍然不能正确描述流体在低渗、特低渗油藏下的渗流规律。本文通过大量的实验重新探讨了在特低渗透油藏中,渗透率、压力以及流量三者之间的关系,得到了其关系表达式。对特低渗透油藏渗流机理的理论研究具有较大的指导意义。

Pores are underdeveloped in low-permeability reservoirs, so permeability and productivity of low-permeability reservoirs can be quite low, and the pressure transits at a very low speed. When a pressure gradient is established in low-permeability reservoirs, the response of production takes a long time period. The Darcy law is improved through experimental studies in this paper. As an experimental rule, the Darcy law has limitations in its applications. For conventional reservoirs, this law is appropriate. However, in low-permeability reservoirs the fluid flows are quite different from those in the conventional ones. An improvement of the Darcy law, based only on the threshold pressure can not properly describe the fluid flow in low-permeability reservoirs. A new relation between the permeability, pressure and rate of flow has to be considered and it is established through experimental studies in the paper. The relation is in an explicit expression, which can be used to study the fluid flow in low-permeability conditions.