A device and method for measuring total volumetric density of rock samples

Abstract

The invention provides a rock sample total volume variable density measuring device and method, belonging to the field of oil and gas geological exploration and development. The rock sample total volumetric density measuring device comprises a magnetic pole (1), a magnetic fluid tank (2) and a sample disk (4); the magnetic pole (1) includes an N pole and an S pole; the magnetic fluid tank (2) It is arranged between the N pole and the S pole of the magnetic pole (1); a magnetic fluid (3) is housed in the magnetic fluid tank (2), and the apparent density of the magnetic fluid (3) can be controlled and adjusted by the action of an external electromagnetic field; The sample disk (4) is arranged in the magnetic fluid tank (2), and is connected with a rock sample weighing instrument (6) arranged outside the magnetic fluid tank (2). The invention utilizes the variable density of the magnetic fluid to realize the rapid measurement of the total volume of the rock sample, optimizes the method for measuring the porosity of the rock sample, shortens the analysis period, and improves the work efficiency.

Description

technical field [0001] The invention belongs to the field of oil and gas geological exploration and development, and in particular relates to a measuring device and method for total volumetric density of rock samples. Background technique [0002] The determination of the total volume of the rock sample is an important link in the determination of the porosity of the rock sample. The existing methods for measuring the total volume of rock samples mainly include the following types. [0003] (1) Buoyancy method [0004] On the basis of drying the rock sample, soak the rock sample to be tested in water (or kerosene). In the weight, and determine the specific gravity of water (or kerosene). Take the rock sample out of the water (or kerosene), wipe off the water (or kerosene) on the surface of the rock sample, weigh the weight of the rock sample in the air after soaking, the weight of the rock sample in the air and in the water (or kerosene) The difference, that is, the buoy...

AI Technical Summary

Problems solved by technology

[0011] ① It is difficult to obtain regular cylindrical rock samples, which limits the application of the measurement method;

At the same time, there are many operating links and the disadvantages of cumbersome operation process

[0013] ③ As far as the gas method is concerned, in the total volume measurement method proposed by Huang Futang et al., due to the complex surface shape of the rock sample, there is a risk that the rubber bushing in the core holder will not be able to stick to the rock sample due to dead angles, and the total volume of the rock sample will be reduced. The volume is too large, which reduces the accuracy of porosity measurement, and is not suitable for clastic rock sample testing

[0015] ⑤ In the method proposed by Shen Yaguang, the key is to control the liquid titration with a liquid level sensor. The size of the "droplet" has a certain impact on the measurement accuracy. At the same time, it does not consider that the rock cuttings are porous materials, and some water will enter the pore system , resulting in an error

[0016] ⑥ The total volume measurement error of the existing clastic rock samples is relatively large, and the accuracy is difficult to control

[0017] In addition, in the field of unconventional oil and gas exploration, especially in the process of shale oil and gas exploration and development, the number of cores taken during the drilling process is small, and it is often difficult to obtain massive core samples, and a large number of cuttings samples cannot be used to measure the porosity of rock samples. test, can not meet the needs of research evaluation work

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