含油气泥质砂岩薄膜电位实验研究

Experiments on the Membrane Potential of the Oilbearing Shaly Sands.

泥质砂岩薄膜电位受到岩石阳离子交换容量、含油气饱和度、接触溶液浓度差的影响 ,纯地层条件推导的用于确定地层水电阻率的自然电位理论模型不适合泥质砂岩地层。研究发现 ,岩石阳离子交换容量、含油气饱和度、相接触溶液浓度差增大 ,均造成薄膜电位升高 ,其中含油气的影响相当于平衡离子浓度的升高。

The membrane potential of the shaly sands is influenced by cation exchange capacity, hydrosaturation and concentration differences between the NaCl solutions. The present method of determining the resistivity of formation water with spontaneous potential logs, which is derived from clean sands theory, is not suitable for the shaly sands. The membrane potential of the shaly sands increases with increment of cation exchange capacity, hydrosaturation and differences of the salinity between the solutions; and the influence of hydrocarbon on the membrane equals that of the changes of cation exchange capacity of the core on it. Also, measurements of the experiments agree well with the theoretical results.