Long rock core holder

Abstract

The invention provides a long rock-core holder comprising a holder cylinder (1) and a high-pressure-resistant rubber sleeve cylinder (2) sleeved in the holder cylinder (1). The high-pressure-resistant rubber sleeve cylinder (2) comprises a cylinder wall (21), an inner cavity (23) positioned in the cylinder wall (21), and cylinder ports positioned on two ends of the inner cavity (23). The inner cavity (23) is in a shape of a straight cylinder. The inner diameter at the cylinder ports on the two ends equals the inner cylinder at the middle of the inner cavity (23). With the holder provided by the invention, long rock core axial multi-oressure-measuring-point detection can be carried out. The method has the advantages of low end face effect, small dead volume, high static confining pressure, and low measurement error.

Description

technical field [0001] The invention relates to the field of petroleum exploration and detection, in particular to a long rock core holder. Background technique [0002] At present, the commonly used core simulation water injection devices are mainly divided into short core and long core systems. Although the use of conventional short cores can quickly evaluate the sensitive characteristics of reservoirs, and can effectively carry out the optimization and research of reservoir protection technology during water injection, but due to the The length of conventional short cores is too short to accurately reflect the process and characteristics of clay hydration expansion and migration during reservoir water injection. In order to further study the reservoir damage mechanism during water injection, on the basis of the conventional short core dynamic anti-swelling experiment, a long core simulation device and an experimental method for long core water injection simulation were es...

AI Technical Summary

Problems solved by technology

However, the conventional multi-point pressure measuring long core device has the following defects: 1. The net confining pressure is low. The core size of the commonly used long core device is Φ25mm*300mm, and double pressure measuring holes can be used for testing

For core holders that can add confining pressure in the axial and radial directions, the sealing form between the rubber tube and the core end face is generally a convex structure (that is, the diameter of both ends of the rubber tube is larger than that of the middle section, or both ends are flared) The main disadvantages of this sealing method are: ①Due to the requirements of the structure and processing technology, the two ends of the rubber sleeve must protrude outward, and the protruding part of the rubber sleeve increases the dead volume of the front and rear ends of the holder, which affects the accuracy of oil-water measurement and the system in the experiment. response speed

②Because there is an inflection point on the protruding part of the rubber sleeve, when the pressure difference between the displacement pressure and the confining pressure is large, the rubber sleeve will be squeezed and deformed from the inflection point inward, and it is easy to leak, so the experimental pressure difference is not high

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