RU1803821C - Device for determining filtration properties of rocks - Google Patents

Abstract

Usage: determination of the filtration properties of rocks in the technique of studying the physical properties of porous bodies, namely, the study of the filtration properties of rocks under high pressure conditions. SUMMARY OF THE INVENTION: The power rod that enters the core holder has mutually perpendicular channels, one of which is not axial through, the other through horizontal. Two channels are made between the axial non-through channel and the lateral surface of the power rod, located perpendicular to the axial non-through channel above and below the through horizontal channel at a distance not greater than the internal height of the bushing of the adapter sleeve relative to the axis of the through horizontal channel. The use of two additional channels introduced in the power rod allows experiments on samples of arbitrary sizes (lengths) within 20-40 mm and to expand the range of measured values of deformation of rock samples without disrupting the hydraulic connection with the device’s communications, making the device universal and stable in work. 3 ill.

Description

The invention relates to a technique for studying the physical properties of porous bodies, and in particular, to investigating the filtration properties of rocks under high pressure conditions.

The aim of the invention is the universality of the device and its stability.

This goal is achieved in that a device for determining the filtration properties of rocks, containing mounted on the frame of the housing of the high pressure chamber in the form of a hollow metal cylinder with a side channel with a fitting for connection to the hydraulic crimping system

and the entry of a squeezing fluid into the internal cavity of the high-pressure chamber and a side channel with a shut-off valve for venting gas from the internal cavity of the high-pressure chamber, a metal insert with inlet and outlet fluid channels with fittings for connection to the hydraulic circuit of the installation, a core holder with an elastic sleeve with rock sample, adapter sleeve with a tuck for hydraulic communication with device communications and a power rod with two mutually perpendicular channels, not axial th and - through horizontal canash about

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hydraulic couplings with a turning adapter sleeve, a plunger connected to the lower part of the power rod, a hollow power cylinder with a channel with a fitting for connection to the hydraulic crimping system and to create axial compression pressure on the rock sample and axial channel through the plunger and power rod, b which has a linear displacement indicator with a holder for measuring the linear (axial) deformation of the sample, sealing rings installed for tightness of the device according to the invention between the axial oznym channel and the side surface of the power rod further two horizontal channel administered extending perpendicularly to the axial neskooznomu channel above and below the horizontal through-channel spaced inner tuck height of metallic bushing with respect to the horizontal axis of the through channel.

The inventive device differs from the main one in that between the axial non-through channel and the lateral surface of the power rod, two channels are additionally introduced, which are perpendicular to the axial non-through channel above and below the horizontal through channel at a distance of the inner height of the transition sleeve relative to the through horizontal channel.

The invention is as follows.

The universality and stability of the operation of the device is determined mainly by the behavior and design features of the power rod, which is pressurized through the plunger by a hydraulic crimping system, creating an external axial crimping of the Ros to the rock sample under study. In this case, the force rod, depending on the deformation ability of the sample, rises to the height of the linear deformation of the test sample, fixed by the linear displacement indicator. The presence in the power rod between the non-through axial channel and the lateral surface of the power rod of two additional introduced channels located perpendicular to the axial non-through channel above and below the through horizontal channel at a distance of the internal height of the tuck of the adapter sleeve relative to the axis of the through horizontal channel provides hydraulic communication with communications device channel, versatility and stability of the device. Additionally introduced upper channel over the through horizontal

The power rod channel is used in the operation of the device in laboratory studies of rock samples with low deformation ability and a length in the range of 30-440 mm. The fluid filtered through the sample enters the axial non-through channel of the power rod, from it, with the maximum length of the sample, into the upper horizontal channel, the adapter sleeve, from which it will have access to the communications of the installation through the adapter adapter. The lower horizontal channel, located under the through horizontal channel of the power rod, is used in the operation of the device for laboratory studies of rock samples with high deformation ability and a minimum length of about 20 mm.

A well-known through horizontal channel between them ensures the operation of the device at a height of rock samples equal to 30 mm, or when examining rock samples with high deformation ability, it is an intermediate channel between additionally introduced upper and lower horizontal channels providing hydraulic communication with adapter sleeve, and from it through the tuck of the adapter sleeve with the communications device.

Figure 1 shows the relative positions of the elements of the claimed device for determining the filtration properties of rocks in an operating mode; figure 2 - a separate unit of the device, core holder; in Fig.3 is a separate element of the device; power stock.

The device (Fig. 1) consists of a chamber body 1 in the form of a hollow metal cylinder, the metal insert 2 assembled with the core holder 3 is screwed into the inner cavity. To create the tightness of the insert 2, sealing rings made of bronze 4 and fluoroplastics 5 are used, and also made of stainless steel 6. Insert 2 is made with inlet 7 and outlet 8 fluid channels in which fittings 9, 10 are installed. The core holder 3 is attached to insert 2, for example, by means of bolts. In the side of the housing 1 there is a channel 11 for supplying a squeezing liquid to the inner working cavity 12 of the chamber 1 and a channel 13 for discharging gas from the inner cavity 12 of the chamber 1 as it is filled with the squeezing liquid. The channels 11 and 13 are made with threads in the outer part. A fitting 14 is installed in channel 11, and a shut-off valve 15 is installed in channel 13. A hollow power screwed into the lower part of the housing 1

cylinder 16 with an internal variable diameter assembly with a plunger 17 of variable diameter, made commensurate with the internal diameters of the hollow power cylinder 16. For tightness of the hollow power cylinder 16, o-rings 18 are installed in the chamber 1 body. Channel 19 is horizontally located in the side wall of the hollow power cylinder 16 with a thread in the outer part, in which the fitting 20 is installed for connection in a hydraulic crimping system that creates axial pressure on the plunger 17. Coaxially with the plunger 17 to the power cylinder 16 by holding of the bodies, consisting of the body of the holder 21, the coupling 22, the clamping screw 23, the stationary part 24 of the linear displacement indicator 25 is fixed. The movable part of the linear displacement indicator 26 touches the lower end of the plunger 17. O-rings 27 are used to seal the holder 21. The device is mounted on a frame 28.

Figure 2 shows a separate unit of the device, the core holder 3, in which a rock specimen 30 is enclosed in an elastic cuff 29, a transition sleeve 31 with a tuck 32, a power rod 33. In Fig. 3, a separate element of the device is shown - a power rod 33 with a non-through axial channel 34, a through horizontal channel 35 and two channels 36, 37.

The device operates as follows,

After assembly, the device is connected to the installation to determine the filtration properties of the rocks. When connecting the device to the hydraulic crimping system to create axial pressure and lateral pressure side, which may be unequal to each other, separate pressure sources are used, for example, in the form of a compressor, hydraulic press, pump, etc. Through the channel 11 with the nozzle 14 and the channel 19 with the nozzle 20, uniformly proportional pressures of Ros and Rbock are created, and through the nozzles 9 and 10 with the supplying 7 and the 8th outlet fluid channels, the working agent is filtered through the test rock sample 30. The channels are threaded in the outer part into which the fittings are installed.

The stresses generated on the specimen of the Ros and Rbock rocks cause deformation of the test specimen.

When connecting the device to the system, hydraulic crimping to create axial pressure ROS into the internal cavity of the metal hollow power cylinder 16 through the nozzle 20 and the channel 19 is supplied

working agent. The hollow master cylinder 16 is made with an internal variable diameter, which makes it possible to proportionally place a plunger 17 of variable diameter in it, made in steps with a large diameter in the upper part and a smaller diameter in the lower part. The lower part of the smaller diameter plunger 17 allows through the axial threaded hole in the outer part and the holder 21 installed in it, in the lower part of the hollow ram 16 to coaxially connect the movable part 26 of the linear displacement indicator 25, which serves to measure axial

deformation lines of the test sample 30. O-rings are installed for the tightness of the hollow power cylinder 16 and the housing of the chamber 1.

Metal holder consisting

from the housing of the holder 21, the coupling 22 and the clamping screw 23 reliably holds the stationary part 24 of the linear displacement indicator 25 so that the movable part 26 of the linear displacement indicator 25 touches the end of the lower part of the plunger 17 of variable diameter. O-rings 27 are used to seal the holder 21 in the housing of the hollow ram 16.

The working agent under pressure falls under the upper part of the plunger 17 of a larger diameter and pushes it up. The axial pressure on the sample 30 is created using the power rod 33 coaxially connected to

with the plunger 17, pressing the sample 30 against the fixed insert 2. Under the action of the stress, the sample experiences linear axial deformation, as evidenced by the movement of the power rod 33 and the plunger 17 coaxially connected to it. The movable part 26 of the indicator 25 follows the movement of the plunger 17 and the arrow deviates the indicator 25 shows the linear strain value which is used to calculate the permeability coefficient CPR of the rock sample 30.

fifty

CRC

where Q is the flow rate of the liquid or gas flowing through the sample;

/ g - viscosity of a liquid or gas; 1 - sample length;

AR Pi-Pa - the pressure difference of the liquid or gas at the inlet and outlet of the sample:

F LG2 is the cross-sectional area of the sample with a radius.

For greater reliability and accuracy of determination of CRC, the values of linear axial strain D | and transverse radial deformation A g of rock sample 30.

When creating lateral pressure Rboc on the sample, the squeezing liquid through the nozzle 14, then the channel 11 enters the internal cavity 12 of the metal hollow single-layer high-pressure chamber 1. The pressure of the compressing liquid is transmitted through the core holder 3 to the elastic cuff 29 and then to the side surface of the rock sample 30.

A gas bubble formed as the squeezing liquid fills the internal cavity 12 of the high-pressure chamber is discharged outwardly through the channel 13 with shut-off valve 15. This allows uniform lateral compression of the sample Rboc.

From the ratio AV AF AI

or

DU-Dg2-D

(2)

where AV is the change in sample volume;

A F is the change in the cross-sectional area of the sample;

A g is the transverse radial deformation of the sample;

A is the axial linear deformation of the sample. We determine the transverse radial deformation of the sample.

The transverse radial deformation A g of the sample is directly proportional to the change in the volume of the AV sample under the action of lateral compression pressure Rboc. Moreover, the AV sample is equal to the amount of squeezing fluid fixed on the hydraulic press scale, which entered the internal cavity of the high-pressure chamber 1 to compress the sample 30 from the initial value P side to a predetermined value. The completion of the deformation is established upon the cessation of the movement of the arrow of the linear displacement indicator 25.

The obtained values of Dg and A are used to determine the coefficient of permeability Kpr due to the presence of deformation of the test sample. Through the fittings 9 and 10 and the channels 7 and 8 in the metal insert 2, which is screwed into the internal cavity of the high-pressure chamber 1 and attached to the code holder 3, the device is connected to the hydraulic circuit of the installation. When connecting the device to the hydraulic system of the installation, the necessary pressure values Pi and Pa are set (for example, using pressure reducers).

Then, a pressure differential is created and the working agent is filtered through the rock test sample 30. In this case, filtration through sample 30 can be carried out both in stationary (with constant pressure drop) and in non-stationary (with variable pressure difference) filtration modes.

5 The filter agent under pressure Pi through the nozzle 9, the fluid supply channel 11 in the insert 2 is evenly distributed over the entire surface of the end face of the rock sample 30.

0 The agent (fluid) filtered through the sample enters the axial non-through channel 34 of the power rod 33, from where it enters the horizontal channel 36 of the power rod 33. After that, it is filtered

5, the fluid enters the adapter sleeve 31 with a tuck 32, from where it is supplied through the device’s communications to a measuring device, for example a flow meter. In the study of highly compressible samples

0 with increased deformation ability or samples in the range of 30-20 mm in length, the power rod 33 can rise above the level of the through horizontal channel 35 of the power rod 33 and above, to the level 5 n of the channel 37 relative to the groove 32 of the adapter sleeve 31.

The amount filtered through the sample of the working agent in the same way as the differential pressure P is introduced into the formula (1)

0 to determine the coefficient of permeability CPR of the test rock sample under conditions of the pressure of the hydrocompression pressure Ros and Rbock on the sample.

The use of a power rod with additionally introduced channels between the non-through axial channel and the lateral surface of the power rod perpendicular to the non-through axial channel above and below the through horizontal channel and

0 located at a distance of not more than the tuck height of the adapter sleeve of the core holder relative to the axis of the through horizontal channel of the power rod allows you to save hydraulic communication

5 communications device when measuring the filtration properties of rocks, to experiment on samples of arbitrary sizes (lengths) within. 20-40 mm, different from the constant sample size of 30 mm as in the prototype and

expand the range of measured values of deformations of rock samples. As a result, the device works universally and stably.

Formulas of the invention

Device for determining filter-filtration properties of rocks according to author. No. 1409894, characterized in that, in order to expand the class of studied subjects

of rock samples, two channels are additionally introduced between the axial non-through channel and the lateral surface of the core core power rod located perpendicular to the axial non-through channel above and below the through horizontal channel at a distance not greater than the internal height of the core adapter sleeve tuck relative to the axis of the through horizontal channel. & yu