RU187392U1 - The arrangement of underground equipment for hydraulic fracturing - Google Patents

Abstract

The utility model relates to the oil industry, and can be used in the development of oil fields using hydraulic fracturing. An arrangement of underground equipment for perforating and hydraulic fracturing, containing an elevator for tubing, a packer, has a circulation valve and a single-blade perforated milled at the end surface, while the area of the holes of the circulation valve communicating the internal cavity of the tubing with the annulus ohm, and the fracture fluid passage area between the production casing and the single-hole perforator is greater than or equal to the internal area of the tubing, while the fracture fluid does not pass through the perforator. Thus, the hydraulic resistance of underground equipment is reduced, the time for pumping the fracture fluid is reduced, energy costs are reduced, the cost of the process as a whole is reduced.

Description

The inventive utility model relates to the oil industry, and can be used in the development of oil fields using hydraulic fracturing.

A known method of hydraulic fracturing and a device for its implementation (patent RU No.2007552, IPC ЕВВ 43/26, application No. 915015826, convention priority. 12/06/1991) containing a tubing string with a perforator having perforations located in one plane conducting slotted perforation, flushing the well, followed by lifting the tubing string with a perforator, lowering it with a packer and injecting fracturing and sand-bearing fluids under pressure, and before conducting slotted perforation, azimuth total orientation of the tubing string with a perforator, stabilize the tubing string from rotation, and slotted hole perforation is carried out in an azimuthally oriented and rotational position of the tubing string, while it is equipped with a tubing located on top of the perforator pipes anchor made in the form of a cylindrical body and installed in it perpendicular to its axis of the pistons with elongated along the axis of the body thrust elements on ends, and the tubing string is made with a mark on the inner surface above the anchor unit, located in the same plane with the perforation holes of the perforator.

The disadvantage of this technical solution is:

firstly, slotted perforation cuts the production string into strips along the axis of the well. The production string does not work for compression. Mountain pressure crushes the production casing during development, or the creation of depression on the formation;

secondly, carrying out work after slotted perforation is extremely dangerous if the work is carried out by lowering the equipment below the perforation zone;

thirdly, in this method, the work is carried out in two stages. The first stage is the lowering of the tubing, perforator and perforation of the formation. Then the equipment is lifted. And the second stage is lowering the tubing, the packer. After the packer is planted, hydraulic fracturing is performed. As can be seen from the above, the time for carrying out the work is increased due to two descents and lifting of the equipment, and accordingly, the costs increase.

There is also known a method of hydraulic fracturing (patent RU No. 2592582, IPC ЕВВ 43/267, publ. 07/27/2016, bull. No. 21), including opening the formation with a vertical well, lowering the pipe string into the well to the interval of the formation and conducting hydraulic fracturing formation - hydraulic fracturing by injection of fracturing fluid along the pipe string; at the wellhead, the lower end of the pipe string is equipped with a slotted perforator with a check valve from below and lowered into the well in the formation interval, backwash in a half times the volume of the well, then through the slotted a drill with orientation in the azimuth of maximum stress cuts the production casing of the well and creates in the interval of the sole and roof of the formation two opposed slots with a diameter of up to 1.5 m and a slot height of 0.2-0.25 of the diameter of the well, and then in the formation between the slots through the slot the perforator by pumping the fracture fluid along the pipe string performs hydraulic fracturing with the formation of fracture cracks, after the formation of the fracture cracks, the cracks are fixed with an ultralight proppant with a density of 1200-1250 kg / m ³ , while the fracture fluid is pumped through the pipe string through the slit perforator is continued and at the same time ultralight proppant is injected into the annulus of the well under pressure not exceeding the allowable on the well walls; upon completion of the crack attachment, the pipe string with the slotted perforator and non-return valve is removed from the well.

The disadvantages of the method are:

firstly, opening the formation with a slotted perforator, cutting through the vertical strips of the casing string, which reduces the strength of the production string;

secondly, the low quality of the opening of the formation due to its secondary mudding during the formation of caverns in the formation by jet nozzles of a slotted punch;

thirdly, it is impossible to pump the appropriate amount of proppant through the hydraulic nozzles due to the large hydraulic resistance;

fourthly, the above equipment is dangerous because of the long equipment after the packer. Slotted perforators have a large length (more than 2500 mm). A single-hole punch has a length of 450 mm. Upon receipt of “stop” - the remains of proppant in the tubing and annulus, a large length of underground equipment remains in the production string with proppant (not all proppant is pumped into the reservoir). Underground equipment is difficult, and in some cases impossible to extract from the well.

The closest technical solution selected by the applicant as a prototype is a device for hydraulic fracturing (patent for utility model RU No. 17980, IPC ЕВВ 43/26, ЕВВ 43/114, publ. March 19, 2018, Bull. No. 8), containing a tubing string equipped with a sandblasting perforator, a check valve is installed at the bottom of which allows proppant to pass through the sandblasting perforator from the annulus, and on the tubing string in front of the sandblasting ohm fixed fiducial gidroyakor pipe and connected to each other fixedly, wherein the sleeve is fixed to fiducial gidroyakorem, as well as on a column of tubing further disposed autonomous unit gauges mounted between gidroyakorem and hydrosandblast perforator.

The disadvantage of this device is:

firstly, the sandblasting hammer has nozzles with a small cross section. The diameter of the nozzles is about 6 mm. When fluid flows through the nozzles, a large hydraulic resistance arises. During hydraulic fracturing, a gel with a high viscosity is used, and it is impossible to pump this fluid (gel) in a short period of time. In this case, time is limited, since after hydraulic fracturing, the gel must decompose and leave the proppant present in the gel in the fracture formed during hydraulic fracturing;

secondly, the fluid used for hydraulic fracturing is a complex chemical compound, and must have certain properties. Namely, hydraulic fracturing fluid is a gel-like product that contains proppant and has a specific structure and decomposes after a certain time. Passing through small openings of jetting nozzles of a sandblasting perforator destroys the gel structure and degrades the quality of hydraulic fracturing as a whole;

thirdly, the sandblasting hammer has a small resource, it is possible to form up to 5 holes, which is very small;

fourthly, when using a sandblasting punch, it is impossible to use a packer. Full hydraulic fracturing is not possible without a packer due to high pressures during hydraulic fracturing, up to 100 MPa. Already at 10 MPa and more, packer systems are used to protect the well as a whole.

The objective of the claimed utility model is to create a reliable, cost-effective device that reduces time and costs for hydraulic fracturing, improves the quality of hydraulic fractures, and improves the reliability of underground equipment.

The technical task is solved by:

reduce the number of trips;

reducing hydraulic fracturing time by increasing flow rate and increasing the cross-sectional area of the hydraulic fracturing fluid flow through underground equipment;

the use of more effective hydromechanical perforation: there is no shock load and high explosive effect - the cement stone behind the production casing is not broken. Close-lying water (interlayers) do not pull up. The production string breaks through to the desired size and does not lose strength characteristics;

the use of cheaper perforation, since a single-blade perforator, milled on the end surface, is the simplest and cheapest to manufacture, among perforators for production casing;

there is no passage of hydraulic fracturing fluid through the perforator (passage of hydraulic fracturing fluid can lead to breakage (due to the presence of proppant - abrasive) equipment).

The claimed technical result is achieved by the fact that the claimed arrangement of underground equipment for perforating and hydraulic fracturing (hydraulic fracturing), containing an elevator for tubing, a packer, has a circulation valve and a single-blade perforator, milled on the end surface, while the area of the holes the circulation valve communicating the internal cavity of the tubing with the annulus and the area of the hydraulic fluid passage between the production string and the single-blade perforator is greater than or equal to the internal area of the tubing, while the fracturing fluid does not pass through the perforator.

What is new is that a circulation valve is used, and the area of the openings of the circulation valve communicating the internal tubing cavity with the annulus is greater than or equal to the internal area of the tubing.

What is new is that the single-blade perforator has milled end surfaces to achieve the required area of fluid passage between the production string and the perforator to reduce the hydraulic resistance of the fluid during hydraulic fracturing.

New is that fracturing fluid does not pass through a hammer drill.

In FIG. 1 shows a diagram of the overall layout of equipment for perforation and hydraulic fracturing.

In FIG. 2 shows a detailed layout of equipment lowered below the packer.

In FIG. 3 shows a section aa. In FIG. 4 shows a section BB.

The general layout includes tubing 1 (see Fig. 1), packer 2, circulation valve 3, single-blade perforator, milled on the end surface 4.

A detailed arrangement of equipment lowering below the packer includes a circulation valve 3 (see Fig. 2) and a single-blade perforator milled along the end surface 4. The area of the holes of the circulation valve for the flow of fluid from the tubing into the annulus (see Fig. 3). The area of the hydraulic fluid passage between the production string and the single-blade perforator (see Fig. 4).

The device operates as follows. Underground equipment for perforation and hydraulic fracturing is lowered into the well in the following sequence (see Fig. 1): a single-blade perforator milled along the end surface 4, a circulation valve 3 communicating the internal cavity of the tubing with the annulus, packer 2, tubing 1. Using geophysical equipment single-hole punch, milled on the end surface, set in the middle of the treated formation. With the annular valve open, and the packer not planted, perforation is performed according to the work plan, creating pressure inside the tubing with the perforation process fluid. When pressure is created, the punch wedge pierces the production string and communicates with the reservoir with the internal cavity of the production string. At the same time, there is no shock load and high explosive effect - the cement stone behind the production casing is not broken. Close-lying water (interlayers) does not pull up. The production string breaks through the right size and does not lose strength characteristics. In view of this, high-quality perforation is obtained. After completion of the perforation, the openings of the circulation valve 3 are opened and the packer 2 is planted. When the packer is seated, hydraulic fracturing fluid (gel with proppant) is pumped into the formation according to the work plan. Hydraulic fracturing fluid (see Fig. 2) passes through the internal cavity of the tubing 1 to the circulation valve 3, then through the openings of the circulation valve into the annular space formed by the outer surface of the circulation valve and the inner surface of the production string, then the space between the production string and one-hole perforator, then through the inner surface of the production casing into the treated area. The cross-sectional areas of the hydraulic fracturing fluid duct from the tubing to the treated zone are equal to, or greater than, the internal tubing area and the fracturing fluid does not pass through the perforator. After the completion of hydraulic fracturing, underground equipment is lifted and the well is mastered.

Thus, the hydraulic resistance of underground equipment is reduced, the time for pumping hydraulic fracturing fluid is reduced, energy costs are reduced, and the cost of the technological process as a whole is reduced.

Claims (1)

A device for arranging underground equipment for perforating and hydraulic fracturing, comprising an elevator for tubing, a packer, characterized in that after the packer there is a circulation valve and a single-blade perforator milled along the end surface, while the area of the openings of the circulation valve communicating the tubing internal cavity with annular space, and the area of the passage of hydraulic fracturing between the production string and single-hole punch is greater than or equal to the inner area di tubing, while hydraulic fracturing does not pass through the perforator.

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