METHOD FOR DETERMINING COEFFICIENT OF EFFECTIVE POROSITY ON CORE SAMPLES Russian patent published in 2013 - IPC G01N15/00 

FIELD: oil and gas industry.

SUBSTANCE: core sample after extraction with solvents, or after extraction with non-aggressive agent, of a flushed non-extracted core sample is dried till constant weight and saturated under vacuum with a formation water model. The sample that is fully saturated with formation water model is suspended in the formation water model and in the displacement fluid. Residual water saturation is created in the sample by displacement of water with displacement fluid (air, gas, kerosene, oil model) till the water escape is stopped, due to centrifugation at maximum revolutions or due to creating maximum pressure in a capillarimeter with a semi-permeable membrane. After residual water saturation is created, the sample is weighted in displacement fluid. Coefficient of effective porosity is determined as per the ratio of difference of weight of the sample fully saturated with formation water model in displacement fluid and weight of the sample saturated with displacement fluid and residual water to difference of weight of fully saturated sample in displacement fluid and weight of fully saturated sample in formation water.

EFFECT: improving reliability of laboratory determination of coefficient of effective porosity of a manifold on core samples, including manifolds with high content of swelling clay component and non-extracted core samples or extracted core samples using non-corrosive agents.