A closed coring saturation correction method based on oil-water phase permeability

Abstract

The invention discloses an oil-water relative permeability-based sealing coring saturability correction method. The method comprises the steps of carrying out an oil-water relative permeability experiment through selecting cores with different physical properties of a target layer and measuring oil-water relative permeability under different water saturation degrees through the experiment; determining an oil-water relative permeability calculation model; and correcting the sealing coring saturability by combining a saturation degree correction value and the sealing coring measurement saturation and determining a sealing coring saturability correction value through an oil-water relative permeability curve in the absence of reduced pressure degassing data of a laboratory, so that the corrected sealing coring saturability is more accurate, the correction method is more reasonable than an existing correction method built on the basis of mathematical statistics, and normalization processing does not need to be carried out on the data.

Description

technical field [0001] The invention belongs to the technical field of rock physics experiment data correction in petroleum exploration, and relates to a closed coring saturation correction method based on oil-water phase seepage. Background technique [0002] Due to the influence of measurement environment, volatilization and degassing and other factors on the closed coring saturation, there is a large difference between the actual measured value and the original value of the formation. Apply effects. Therefore, the research on the correction method of airtight coring saturation is the focus of people's long-term attention. [0003] At present, there are two main methods for correcting the oil-water saturation of closed coring. One is based on petrophysical experiments, which measure the loss of water saturation through experiments, and indirectly correct the oil saturation by correcting the water saturation. Take the saturation correction formula as an example to illustr...

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Problems solved by technology

[0008] The accuracy of the airtight coring saturation correction method established by the simulation experiment is greatly affected by the characteristics of the selected samples and the number of samples, and the whole experimental process is carried out under high temperature and high pressure for a long period of time and high cost; the rest of the methods are based on mathematical statistics Correcting the saturation directly often leads to the correction amount of the saturation being greater than the actual change value, which needs to be normalized. At the same time, it does not consider that the relative seepage capacity of oil and water changes gradually during the process of saturation loss, and the amount of oil and water loss is a constant. Due to a nonlinear change process, it is impossible to accurately and effectively determine the correction amount of closed coring saturation

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