在分析低渗油田国家分类标准的基础上,基于低渗油田启动压力梯度和岩心应力敏感性实验,形成了我国海上低渗油田分类标准:渗透率在10～50 mD的油田为一般低渗透油田,此类油田储层可忽略启动压力梯度和压敏效应;渗透率在5～10 mD的油田为特低渗透油田,此类油田储层存在启动压力梯度,但压敏效应可忽略;渗透率低于5 mD的油田为超低渗透油田,此类油田储层同时存在启动压力梯度和压敏效应.根据这一分类标准,可以较好地梳理中国近海低渗油田的油气资源,筛选出在目前技术和经济条件下适合开采的低渗油田.%According to an analysis of the national classification for low-permeability oilfields and some experiments of threshold pressure gradient and core stress sensitivity in low-permeability oilfields, a new classification was developed for the low-permeability oilfields offshore China. In this new classification, the oilfields with permeability between 10 ～ 50 mD are considered as GENERAL low-permeability oilfields, in whose reservoirs the effects of threshold pressure gradient and stress sensitivity can be ignored; the oilfields with permeability between 5～10 mD are referred to SPECIAL low-permeability oilfields, in whose reservoirs the stress sensitivity effect can be ignored, but the effect of threshold pressure gradient exists; and the oilfields with permeability below 5 mD are referred to ULTRA low-permeability oilfields, in whose reservoirs both the effects of threshold pressure gradient and stress sensitivity exist. This new classification can be used to classify reasonably the low-permeability hydrocarbon resources offshore China and select the low-permeability oilfields that can be developed effectively under the present technology and economy.
展开▼
