Reusable steel rock core for multistage pre-shearing of chromium gel system

Abstract

The invention provides a reusable steel rock core for multistage pre-shearing of a chromium gel system. The reusable steel rock core comprises a first rock core with a central shaft hole, a second rock core with a central shaft hole and N connecting rock cores with central shaft holes; the end surface at one side of the first rock core is provided with a boss structure; the end surface at one sideof the second rock core is provided with a groove structure; the end surface at one side of each of the connecting rock cores is provided with a boss structure, and the end surface at the other sideof each of the connecting rock cores is provided with a groove structure; the first rock core, the connecting rock cores and the second rock core are sequentially butt-jointed and buckled into a wholeby the boss structure and the groove structures, and the butt-jointed and buckled parts are sealed; closed spaces are reserved on butt joint ports between the boss structures and the groove structures after the first rock core, the connecting rock cores and the second rock core are butt-jointed and buckled into a whole; and the closed spaces are internally provided with screens. The problems of nonrepeatability and rock core waste caused when the chromium gel system is pre-sheared indoors by using a man-made sandstone core in the prior art and the problem that the gelling time and gelling strength of the chromium gel system cannot be controlled are solved.

Description

technical field [0001] The invention relates to a rock core used for pre-shearing when evaluating the oil displacement effect of chromium gel. Background technique [0002] When using natural sandstone cores or artificial sandstone cores to evaluate the oil displacement effect of chromium gel in the laboratory, the conventional pre-shearing method is to carry out the oil displacement experiment after the chromium gel system passes through the artificial core with high permeability. The disadvantage is that it is non-repeatable, resulting in waste of core. Secondly, due to the difference in cementation degree and pore structure characteristics inside the artificial sandstone core, the shear rate is different, so that the consistency of the chromium gel after each pre-shearing in terms of apparent viscosity and molecular structure cannot be guaranteed, resulting in chromium The time, strength and depth of the gelation of the gel system are uncontrollable, which will cause pre...

AI Technical Summary

Problems solved by technology

[0003] In view of this, the present invention provides a reusable steel core for multi-stage pre-shearing of the chromium gel system, which solves the problem of unrepeatable pre-shearing of the chromium gel system by using artificial sandstone cores indoors And the problem of core waste, and because of the different pore structure characteristics of artificial cores, resulting in different shear rates, it is impossible to control the gelling time and gelling strength of the chromium gel system, resulting in premature gelation of the chromium gel system and serious problems End face effect, the problem that leads to the failure of the experiment

Images