RU220168U1 - CORE HOLDER - Google Patents

Abstract

The utility model relates to the oil and gas industry for rapid performance assessment of the sand-holding capacity of samples of downhole well filters. The technical result is to increase the uniformity of filtration of working agents. By etching concentric circles on the inner surface of the plunger, the device makes it possible to increase the uniformity of filtration at the initial stages of experiments.

Description

The utility model relates to the oil and gas industry for rapid performance assessment of the sand-holding capacity of samples of downhole well filters.

A core holder is known (patent RU No. 111664 U1, published on December 20, 2011), containing a hydraulic crimping chamber that creates axial crimping pressure using a rubber cuff; plungers for supplying and discharging working agents with valves, which provides the design possibility of filtering both one agent with one of the valves closed, and the joint filtration of two immiscible liquids with two open valves; a void space within the rubber collar to accommodate at least one core sample.

The disadvantage of this device is the presence of a rubber cuff, which is vulnerable to work in an aggressive sand-saturated environment.

A core holder is known (patent RU No. 2239047 C2, published on October 27, 2004), which includes a core holder body, a system of spring arched petals made with a strictly specified petal width - from 1.4 to 1.6 diameters of the core receiving hole. The device is intended for sampling core material from loose and highly friable rocks, and is thus not suitable for laboratory research.

The disadvantage of the device is the presence of blades for holding the core, which over time can be subject to erosion.

A core holder is known (author's certificate SU No. 1247723 A2, published on July 30, 1986), which includes a cylindrical core holder body, a system of fittings, a rubber cuff placed in a special sleeve, sealing plungers with through holes for fluid supply, sealing cones that prevent corrugation of the cuff surface.

The disadvantage of this device is the only channel for filtration of working agents, which can lead to uneven filtration of fluids when working with highly permeable samples of core material.

There is a known method for sealing a cylindrical core and a method for assembling a seal in a core holder (patent RU No. 2720208, published on April 28, 2020), including a core holder body and two sealing plungers. A special feature of the product is the ability to use thermally expandable graphite to create a comprehensive compression on the core in order to conduct experiments at pressures up to 20 MPa and temperatures up to 400 degrees Celsius.

The disadvantage of the device is the presence of thermally expandable graphite to create the crimping pressure, since the device is designed to conduct experiments at extreme pressures and temperatures.

A core holder is known (patent RU No. 2685466, published on April 18, 2019), which includes a core holder body, pressing upper and lower plungers, equipped with through holes for the supply and removal of working agents, including gaseous ones, as well as a system of 7 fittings located along the length core holder in three sections - 2 sections with three fittings, one section with one fitting - for supplying shielding chemicals used in the oil and gas industry.

The disadvantage of this device is the presence of fittings along the body of the core holder, which can be clogged with sand during experiments.

The technical result is to increase the uniformity of filtration of working agents.

The technical result is achieved by the fact that the ends are rigidly attached to the body at the top and bottom, which are made in the shape of a square, in the center of which there is a hole, the diameter of which corresponds to the internal diameter of the body, while the plungers are installed with the possibility of removal from the top and bottom to the ends, in the center of each a through axial channel is made from the plungers, on the walls of which there is a thread, with the possibility of connecting a pump, which goes into a filtration channel of a smaller diameter, concentric circles are applied to the inner surface of the plungers, and on its corner sections there are holes in which fasteners are removably installed, Inside the lower part of the housing above the lower plunger there is a removable cone installed, the hole in the lower part of which is coaxially connected to the filtration channel and the through axial channel.

The core holder is illustrated by the following figures:

fig. 1 – assembled device;

fig. 2 – 3D model of the device;

fig. 3 – cover, bottom view;

fig. 4 – cover, side view;

1 – body;

2 – cone;

3 – plunger;

4 – sealing rings;

5 – fastening;

6 – through axial channel;

7 – filtration channel;

8 – sand pack;

9 – filter coupon;

10 – end,

11 – concentric circles

The core holder contains a body 1 (Fig. 1, 2) made in the form of a hollow cylinder, for example, made of steel grade steel 10. At the top and bottom of the body 1, ends 10 are rigidly attached, made in the shape of a square, in the center of which there is a hole, the diameter of which corresponds to the inner diameter of the housing 1. At the ends 10, at the top and bottom, plungers 3 are removably installed, in the center of which there is a through axial channel 6 (Fig. 4), on the walls of which there is a thread, with the possibility of connecting a pump. The through axial channel 6 goes into a filtration channel 7 of smaller diameter. Concentric circles 11 are applied to the inner surface of the plungers 3 (Fig. 3). At the corner sections of the plungers 3 there are holes in which fasteners 5 are removably installed. Inside the lower part of the body there is a removably installed cone 2, the hole in the lower part of which is coaxially connected to the filtration channel 7 and the through filtration channel 6.

The core holder works as follows.

Through the lower end, a cone 2 is placed inside the core holder body 1 to collect sand, after which the lower end is closed with one of the plungers 3. A filter coupon 9 is placed through the upper end with the filter surface oriented towards the upper end. A sand pack 8 is placed on the filter coupon 9, which is a placer of reservoir rock with a previously known granulometric composition. The rock to form the sand unit 8 should be mixed in advance with the fluid that will be used during the experiment, in a volume equal to 1.5 pore volumes of the proposed sand unit 8. Next, the sand unit 8 is compacted in the internal space of the core holder. After this, the upper end of the core holder body 1 is closed with a plunger 3 with concentric circles 11 and compacted into a sand pack 8 using fasteners 5. Next, the lower fasteners 5 are secured.

A pump is connected to the upper end of the core holder through a through axial channel 6 and fluid is supplied with a given pressure, as well as the injection pressure is estimated. Through the lower end of the core holder, centralized collection of fluid samples with removed rock occurs. Rock samples are further analyzed.

By etching concentric circles on the inner surface of the plunger, the device makes it possible to increase the uniformity of filtration at the initial stages of experiments.

Claims (1)

A core holder, including a body with plungers located at the top and bottom with through axial channels, characterized in that the ends are rigidly attached to the body at the top and bottom, which are made in the shape of a square, in the center of which there is a hole, the diameter of which corresponds to the inner diameter of the body, while the plungers installed with the possibility of removal from the top and bottom at the ends, in the center of each of the plungers there is a through axial channel, on the walls of which there is a thread with the possibility of connecting a pump that goes into a filtration channel of a smaller diameter, concentric circles are applied on the inner surface of the plungers, and on its angular In areas there are holes in which fasteners are removably installed; inside the lower part of the housing above the lower plunger there is a removably installed cone, the hole in the lower part of which is coaxially connected to the filtration channel and the through axial channel.