Device for evaluating efficiency of nozzle designs for cutting pipes in well

Abstract

FIELD: oil and gas industry.SUBSTANCE: device for evaluating the efficiency of cutting pipes in a well using various nozzle designs. The device includes a well, a casing pipe plugged at the bottom, a wellhead flange located on the upper end of the casing pipe, a support flange installed on the wellhead flange, equipped with a spool for draining liquid and a preventer, a flexible pipe (FP) column, a discharge line of a pipeline with a pump unit and a dispenser and a discharge line from the casing column with a trough tank, means for measuring pressure, liquid flow and time. The tubing pipe (TP) lowered into the casing is secured to the support flange and sealed at the bottom with a plug. A FP column, equipped with a nozzle from the bottom up and a screw downhole motor that rotates the nozzle, is lowered through the preventer into the TP, ensuring that the TP is cut off. The trough tank is equipped with a discharge line from the TP column hydraulically connected to the inter-column space of the well. The FP column above the preventer is equipped with a weight made in the form of metal disks. Each disk is rigidly fixed on the outer surface of the FP column. The weight of the load is adjusted depending on the hydraulic pressure created in the device when cutting the casing.EFFECT: increasing the efficiency of pipe cutting, reducing vibration loads on the nozzle during the cutting process, and improving the industrial safety of service personnel performing pipe cutting in the well.1 cl, 2 dwg, 1 tbl, 1 ex

Description

[0001] The invention relates to the field of the oil and gas industry and relates to devices for evaluating the efficiency of cutting pipes in a well with various nozzle designs.

[0002] A hydraulic monitor nozzle for a hydromechanical hammer drill is known (RU patent No. 2338056, published on 10.11.2008), having a channel for forming a liquid jet, which is made with a conical converging nozzle that forms an acceleration chamber and is connected to a cylindrical section of the channel, the angle of entry of the conical nozzle is 13-14°, and the length of the acceleration chamber is 1.3-1.7 times the diameter of the channel.

[0003] Disadvantages of the device:

[0004] - firstly, low cutting efficiency due to the long duration of cutting pipes in the well;

[0005] - secondly, strong vibration of the nozzle during the process of hydromonitor cutting of the casing, due to which the cutting direction is disrupted (an even circle around the perimeter of the cut pipe);

[0006] - thirdly, limited functionality, namely the impossibility of the technological operation associated with cutting pipes in the well;

[0007] - fourthly, low safety of working personnel at the wellhead, since a water-sand mixture is prepared and used during the cutting process at the wellhead.

[0008] The closest device in technical essence and the achieved result is a device for evaluating the efficiency of various designs of nozzles for hydromonitor perforation of a casing string, containing a wellbore, a casing pipe plugged from below, a wellhead flange located on the upper end of the casing pipe, a support flange installed on the wellhead flange, equipped with a spool for draining liquid and a preventer, a flexible pipe column (FPC) equipped with a nozzle at the bottom and a weight at the top, a discharge line of a pipeline with a pumping unit and a dispenser and a discharge line with a trough tank, as well as means for fixing, measuring pressure, liquid flow rate and time (RU patent No. 2851365, published 11 / 24 / 2025). The casing pipe is coaxially cemented in the tank. A string of flexible tubing is lowered through the wellbore preventer into the casing. A pumping unit with a dosing unit, located on the pipeline's discharge line, supplies a water-sand mixture to the jetting nozzle.A hydrocyclone is located on the flow line. The load is a metal cylinder, the diameter and length of which depend on the depth of the gas turbine string, rigidly attached to the body of the gas turbine string above the preventer.

[0009] Disadvantages of the device:

[0010] - firstly, low cutting efficiency, due to the long duration of cutting pipes in the well due to the fact that it is possible to determine a nozzle that allows cutting the casing with a minimum amount of time;

[0011] - Secondly, strong vibration of the nozzle during hydromonitor cutting of the casing string disrupts the cutting direction (a smooth circle around the perimeter of the cut pipe) due to the weight placed on the casing string. The weight of the weight strengthens the casing string and reduces its vibrational movement during hydromonitor cutting;

[0012] - thirdly, limited functionality, namely the impossibility of the technological operation associated with cutting pipes in the well;

[0013] - fourthly, low safety of working personnel at the wellhead, since a water-sand mixture is prepared and used during the cutting process at the wellhead.

[0014] The technical objectives of the invention are to increase the operating efficiency of a device for evaluating the efficiency of nozzle designs for cutting pipes in a well, to reduce vibration loads on the nozzle during the cutting process by installing a load on the GT column, as well as to expand the functional capabilities of the device and to increase the efficiency of pipe cutting and the industrial safety of service personnel performing pipe cutting in a well.

[0015] Technical problems are solved by a device for evaluating the efficiency of nozzle designs for cutting pipe in a well, including a well, a casing pipe plugged at the bottom, a wellhead flange located on the upper end of the casing pipe, a support flange installed on the wellhead flange, equipped with a spool for draining liquid and a preventer, a flexible pipe column (FPC) equipped with a nozzle at the bottom and a weight at the top, a discharge line of a pipeline with a pumping unit and a dispenser and a discharge line from the casing column with a trough tank, as well as means for measuring pressure, liquid flow and time.

[0016] What is new is that the tubing pipe (TP) lowered into the casing pipe is fixed on the support flange, plugged from below with a plug, and the GT string is lowered through the preventer into the tubing, and the GT string is equipped from the bottom up with a nozzle and a screw downhole motor that drives the nozzle into rotation, ensuring the cutting of the tubing, and the trough tank is equipped with a discharge line from the tubing string hydraulically tied to the annular space of the well, and the GT string above the preventer is equipped with a weight, and the weight is made in the form of metal disks, and each disk is rigidly fixed on the outer surface of the GT string, and the weight of the weight installed on the GT string is regulated depending on the hydraulic pressure created in the device during the cutting of the tubing.

[0017] Fig. 1 schematically shows a device for evaluating the effectiveness of various designs of nozzles for cutting pipe in a well.

[0018] Fig. 2 schematically shows a device for evaluating the effectiveness of various nozzle designs after cutting a pipe in a well.

[0019] The device in the figures is designated by the following positions: 1 - casing string; 2 - plug; 3 - wellhead flange; 4 - support flange; 5 - pipe, such as tubing; 6 - tubing plug; 7 - spool; 8 - preventer; 9 - annular space of GT - tubing; 10 - flexible tubing string (CT); 11 - downhole motor; 12'; 12''; 12''' - nozzle; 13 - lifting beam; 14 - elbow; 15 - load; 16 - pump unit; 17 - flow meter; 18 - feed pressure gauge; 19 - flow line pressure gauge; 20 - trough tank; 21 – flow line from the casing; 22 – flow line from the tubing; 23 – inter-column space of the tubing – casing.

[0020] A device for evaluating the efficiency of various designs of nozzles 12'; 12''; 12''' (Fig. 1-2) for cutting a pipe - tubing 5, includes a well, wherein a casing pipe 1 is placed in the well, plugged at the bottom with a plug 2.

[0021] At the upper end of the casing pipe 1, a wellhead flange 3 is located, and a support flange 4, equipped with a spool 7 and a preventer 8, is mounted on the wellhead flange. Spool 7 allows waste fluid to be diverted from the annular space 9 into a trough tank. Pump unit 16 is located on the discharge line of the pipeline (Fig. 1).

[0022] A tubing 5 lowered into a casing pipe 1 is fixed to the support flange 4 and sealed at the bottom with a plug 6 (Fig. 1).

[0023] A string of flexible pipes 10 is lowered through the preventer 8 into the tubing 5 (Fig. 1-2).

[0024] The GT 10 column is equipped from the bottom up with a 12'; 12''; 12''' nozzle and a screw downhole motor 11, which drives the 12'; 12''; 12''' nozzle to cut off the tubing 5.

[0025] Pumping liquid by a pumping unit through a flexible pipe string 10 under pressure, for example, 8.0 MPa, to convert the pressure of the injected liquid into rotational movement of the output shaft of the downhole motor 11, which drives the nozzle 12'; 12''; 12''' to cut off the tubing 5 with the release of the spent liquid through the annular space 9 between the GT and the tubing and through the first discharge line 21 into the trough tank 20 (Fig. 1).

[0026] The device for evaluating the efficiency of various designs of nozzles for cutting pipes in a well is equipped with time recording and pressure measurement devices - a pressure gauge on the feed 18 (Fig. 1), a pressure gauge on the discharge line 19, and a liquid flow meter 17.

[0027] To evaluate the performance of different designs of 12'; 12''; 12''' nozzles for cutting pipes: in NKT 5, studies were conducted, for example, for three different designs of 12'; 12''; 12''' nozzles under equal conditions.

[0028] For a reliable comparison, three tubing columns (NKT 5) of equal diameters were prepared, for example, 73 mm with a wall thickness of 5.5 mm according to GOST 633-80. A liquid, for example, wastewater with a density of 1100 kg / m3, was pumped through a GT 10 column (for example, with a diameter of 31.75 mm) using a pump unit (16), for example, a CA-320 pump unit. 3 with the same flow rate, and cutting was carried out for a time sufficient for the liquid to exit the annular space 22 between the casing pipe and the tubing.

[0029] Example of pipe cutting efficiency evaluation.

[0030] The design of the device used a well into which a casing string 1 with a depth of 6 m was lowered with a plug 2 installed at the bottom and a wellhead flange 3 at the top. The wellhead flange 3 of the casing string 1 was secured

[0031] A support flange 4 is installed on the wellhead flange, equipped with a coil 7 for draining liquid and a preventer 8; a pumping unit with a dispenser is placed on the discharge line of the pipeline.

[0032] Then they secured the tubing 5 with a diameter of 73 mm and a wall thickness of 5.5 mm to the support flange 4, plugged from below, and lowered it into the casing string 1, for example, with a diameter of 146 mm and a wall thickness of 7 mm, secured to the wellhead flange 3.

[0033] A spool 7 for draining liquid and a preventer 8 for sealing the annular space 9 between the tubing 5 and the flexible pipe 10 were installed on top of the support flange 4.

[0034] Before lowering the flexible pipe 10, the downhole motor 11 and the nozzle 12' (12'' or 12''') were screwed on to cut the pipe onto the lower end of the GT 10 with a diameter of 31.75 mm. Using the mast of the lifting beam 13 (Fig. 1), the GT string 10 was lowered through the preventer 8 and the spool 7 by the elbow 14 to the point where the tubing pipe 5 was cut, after which the load 15 was installed (Fig. 1).

[0035] The GT column 10 above the preventer 8 is equipped with a weight 15. The weight 15 (Fig. 1 and 2) is made in the form of metal disks 15'; 15''…15 n Each metal disk is 15'; 15''…15 n is rigidly fixed, for example, with the help of a ring clamp (shown conditionally in Fig. 1) on the outer surface of the GT 10 column. The weight of the load 15 installed on the GT 10 column is adjusted depending on the hydraulic pressure created in the device when cutting the casing column and is selected empirically from Table 1 below.

[0036] Table 1 Determination of the load weight depending on the pressure created in the device.

[0037] Item No. Pressure in the device, MPa Load weight, kN 1 up to 15.0 MPa 1,0 2 15.0 - 20.0 MPa 1,5 3 20.0 - 25.0 MPa 2,0 4 25.0 – 30.0 MPa 2,5 5 More than 30.0 MPa 3,0

[0038] Load 15 creates additional weight for the GT 10 column, which reduces vibration loads when cutting tubing 5 with 12'; 12''; 12''' nozzles, due to which the cutting direction is not disturbed and an even circle is obtained around the perimeter of the cut pipe.

[0039] The rams of the preventer 8 on the GT column 10 were sealed. The stand was tied up as shown in Fig. 1.

[0040] To pump through the stand, we used technical water in a volume sufficient for the stand operation and cutting off the tubing pipe.

[0041] Pump unit 16 (Fig. 1) was started and GT 10 was filled with fluid. The fluid flow rate was then adjusted according to the manufacturer's recommendations for downhole motor 11, which was monitored using flow meter 17 (Fig. 1). Pressure was monitored using pressure gauges 18 and 19.

[0042] Technical water was pumped through the GT 10 column and then through the annular space 9 of the GT 10 and the tubing 5, into the trough tank 20 for a time sufficient to cut the tubing 5 pipe. The shutdown time of the rig was recorded by the presence of technical liquid in the flow line 21 (Fig. 1), since the annular spaces 9 and 22 begin to communicate after the tubing pipe is cut. (See Fig. 2). The testing time with the 12' packing took 43 minutes; a smooth cut perpendicular to the pipe axis was obtained.

[0043] Pumped out process water from casing pipe 1 and removed the cut section of the tubing for further examination.

[0044] Next, similar tests were conducted with 12" and 12" nozzles. The cutting depth and time were determined to be 68 minutes with the 12" nozzle and 75 minutes with the 12" nozzle. The results were uneven cuts, 5 degrees off-axis, and burred and outward-bent edges.

[0045] Based on the research results, it was found that the 12' nozzle for cutting NKT 5 pipes is the most effective of the considered designs of 12'; 12''; 12''' nozzles, as it ensures minimal cutting time and high quality of the cut edge.

[0046] The functionality of the device is expanded, namely, the device allows for the technological operation associated with cutting pipes in a well.

[0047] The proposed device allows you to increase the efficiency of cutting pipes, since it allows you to determine the nozzle with which the minimum time is spent on cutting pipes, as well as to determine the nozzle with the lowest vibration load during the cutting process in order to obtain a smooth cut of the pipe without deviations from the central axis, without burrs and bending.

[0048] Industrial safety of service personnel is increased during the cutting process, since a water-sand mixture is not prepared at the wellhead and is not used during the pipe cutting process.

[0049] The proposed device for evaluating the efficiency of pipe cutting nozzle designs allows:

[0050] - improve the efficiency of pipe cutting;

[0051] - reduce vibration loads on the nozzle during the cutting process;

[0052] - improve industrial safety of service personnel performing pipe cutting in a well.

Claims

A device for evaluating the effectiveness of pipe cutting nozzle designs in a well, comprising a well, a casing pipe plugged at the bottom, a wellhead flange located on the upper end of the casing pipe, a support flange mounted on the wellhead flange, equipped with a spool for draining liquid and a preventer, a flexible tubing (CT) column equipped with a nozzle at the bottom and a weight at the top, a discharge line of a pipeline with a pump unit and a dispenser and a discharge line from the casing column with a trough tank, as well as means for measuring pressure, fluid flow and time, characterized in that a tubing pipe (TU) lowered into the casing pipe, plugged at the bottom with a plug, is fixed on the support flange, and a CT column is lowered through the preventer into the CT, wherein the CT column is equipped from the bottom up with a nozzle and a screw downhole motor that drives the nozzle, providing cutting of the tubing, while the trough tank is equipped with a discharge line from the tubing column,hydraulically connected to the annular space of the well, while the GT column above the preventer is equipped with a load, and the load is made in the form of metal disks, and each disk is rigidly fixed on the outer surface of the GT column, and the weight of the load installed on the GT column is adjusted depending on the hydraulic pressure created in the device when cutting the tubing.

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