A large-scale rock core for relative permeability curve determination and its preparation method

Abstract

The invention discloses a large-size rock core for measuring relative permeability curves and a preparation method thereof. The preparation method comprises the following steps: (1) mixing and stirring quartz sand and cement to obtain a quartz sand mixture; (2) filling the quartz sand mixture into a mold, pressing it with a briquetting block and performing compaction treatment; the mold is in the shape of a cuboid (3) The compacted mold is placed in a constant temperature box for core forming, and the core is obtained by taking out the mold; (4) The core is fixed in the mold again, and epoxy resin is cast to obtain the target core. The present invention has the following advantages: 1. Compared with the existing small-sized rock cores for measuring relative permeability curves, the measurement error of large-sized rock cores is smaller and the result is more accurate; 2. By setting diversion covers at both ends of the rock core, the errors due to end effects.

Description

technical field [0001] The invention relates to a large-size rock core used for measuring relative permeability curves and a preparation method thereof. Background technique [0002] The relative permeability curve is one of the most important data for basic reservoir research. It can predict oil well production, water-oil ratio, oil well water production law, oil displacement efficiency and recovery factor at different development stages. Its accuracy will directly affect people's understanding of reservoir water displacement characteristics and various calculations, so it is very important to correctly obtain the representative oil-water relative permeability curve of the reservoir. At present, for the determination of the relative permeability curve, most of the small cores taken from natural cores are used. For example, the patent application number 201611094637.7 discloses a method for the determination of the gas-water relative permeability curve of tight sandstone ste...

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Problems solved by technology

At present, for the determination of the relative permeability curve, most of the small cores taken from natural cores are used. For example, the patent application number 201611094637.7 discloses a method for the determination of the gas-water relative permeability curve of tight sandstone steady state method, which uses small rocks. In order to overcome the end effect, the literature "Calculation of Relative Permeability Curves at Different Positions in Long Core Flooding" uses multiple small cores spliced ​​into long cores, but the calculation of core permeability is too complicated

At the same time, because the relative permeability curve of the small core test has high requirements for the measurement of the produced fluid, errors are prone to occur, and the use of small cores cannot simulate the conditions of thick oil layers.

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