不同压力下气层岩样m、n值变化的实验研究

Variation of m and n in gas reservoir under different pressure

胶结指数m和饱和度指数n变化规律的研究一直是岩石物理学家和测井解释分析家关注的问题。压力是影响m、n的重要因素,但迄今为止,仍未取得可使多数人接受的一般性结论。实验开展了低孔隙度低渗透率气层岩样在不同压力条件下的电阻率测量,在考虑孔隙度随压力变化的基础上建立了m、n参数随压力变化的关系,得出结论:某些地区的气层岩样在压力增大时即使考虑孔隙度变化,m值增大,n值减小。

The change of cementation exponent m and the saturation exponent n is always concerned by the rock physicists and the well logging interpretation analysts. The pressure is one of the important factors that affect m and n. But up to now, the general conclusion which can be accepted by most people still has not been obtained. The resistivities of rocks with low permeability and low porosity of the gas reservoir are measured under different pressure in this experiment. With the consideration of porosity varied with pressure, the relations of the parameter m and n under the low porosity and low permeability condition are established and discussed in theory. The conclusion is given that the m value increases and the n value reduces with the consideration of porosity variation when the pressure is increased.