A method for on-site butt-jointing and lengthening of continuous pipe

Abstract

The present invention provides a method for on-site docking and lengthening of coiled tubing, which uses two trailers to independently transport the main and auxiliary drums to the well, and utilizes the hydraulic lifting structure of the main drum. When winding the large-diameter coiled tubing, the high point of the wheel rim is adjusted to the minimum height above the ground through the hydraulic lifting structure to ensure that the road transportation requirements are not exceeded when transporting to the well; the high point of the main drum wheel rim is adjusted to the maximum height above the ground at the operation site, and the two drum coiled tubings are all wound back around the main drum after docking, and the length of the coiled tubing meets the well depth requirements for ultra-long horizontal wells / ultra-deep wells. The on-site docking and lengthening method of coiled tubing breaks through the limitation of the capacity of the coiled tubing drums under road transportation conditions, makes up for the short board of the coiled tubing operation process caused by the drum capacity not being able to meet the operating depth of ultra-long horizontal wells / ultra-deep wells, and achieves the goal of transporting ultra-long coiled tubing to the well site and down to the bottom of the well, expanding the scope of implementation of the coiled tubing operation process.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas field development, and in particular relates to a continuous pipe on-site docking and lengthening operation method. Background Art

[0002] The underground operation of ultra-deep wells and ultra-long horizontal wells brings great opportunities for coiled tubing construction. In order to solve the problem of coiled tubing depth in long horizontal well construction, research on the construction technology of coiled tubing for long horizontal wells has been carried out at home and abroad, and a series of coiled tubing underground vibration friction reduction technology and vibration friction reduction tools, coiled tubing straightening technology, and a series of drag reducers have been formed. However, due to the limitations of coiled tubing drum capacity and road transportation conditions, there is currently no mature and reliable method for reference to solve the problem of tube length in ultra-deep and ultra-long horizontal well construction. Summary of the invention

[0003] The object of the present invention is to provide a method for on-site butt-jointing and lengthening of a coiled pipe to overcome the above technical defects.

[0004] In order to solve the above technical problems, the present invention provides a method for on-site butt-jointing and lengthening of a coiled pipe, comprising the following steps:

[0005] S1. Double drums are independently transported to the well, and the double drums include a main drum and a secondary drum;

[0006] S2. Extract the ends of the coiled pipes wound on the two drums respectively and connect them on site to increase the capacity of the main drum;

[0007] S3. All the coiled tubes on the auxiliary drum are transferred to the main drum to start construction;

[0008] S4. After the construction work is completed, the underground continuous pipe is rewound to the main drum and auxiliary drum;

[0009] S5. Two rollers are transported and withdrawn independently.

[0010] Furthermore, the double drum described in S1 is independently transported to the well, and the double drum includes a main drum and a secondary drum, wherein the main drum includes a drum body and an expansion body, and the drum body includes a working shaft for winding the continuous pipe and rims installed at both ends of the working shaft, and the two rims have the same structure, and the edge of each rim is a quasi-circular structure that is symmetrical about the center of the circle by connecting the first arc segment, the first straight segment, the second arc segment and the second straight segment in sequence end to end, and the expansion body can be detachably installed on each straight segment and can be folded and spliced ​​along the straight segment, and the expansion body and the drum body after splicing and assembly are circular as a whole;

[0011] During the transportation of the main drum, the drum body needs to be hydraulically lowered first so that the high point of the wheel rim is adjusted to the minimum height from the ground.

[0012] Furthermore, the continuous pipe ends wound on the two drums are respectively extracted and connected on site to increase the capacity of the main drum, which specifically includes:

[0013] Connect the main drum to the continuous pipe operation machine, unfold the expansion body, make the rim of the main drum a complete circle to achieve capacity increase, hoist the double drums so that the distance between the two drums is greater than or equal to 30m, use a crane to pull out the continuous pipe ends of the two drums and place them on the ground, first use straightening tools to straighten the continuous pipe ends of the main and auxiliary drums respectively, and then use an internal grinder to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively to ensure that there is no rust and oil on the welds, fix the continuous pipe ends of the main and auxiliary drums on the welding operation platform respectively, and weld the continuous pipe ends of the two drums after the joints are aligned.

[0014] Furthermore, in step S3, all the continuous pipes on the auxiliary drum are turned over to the main drum to carry out the construction operation, which specifically includes:

[0015] Open the pipe reverser and reverse the coiled tubing from the auxiliary drum to the main drum until only the bottom coiled tubing is left on the auxiliary drum. Then stop reverse pipe, cut the tubing, and make a windable connector on the end of the bottom coiled tubing left on the auxiliary drum. Use the main drum after capacity expansion and reverse pipe to implement single-drum single-pipe well-entry construction.

[0016] Further, after the construction work in S4 is completed, the underground coiled tubing is rewound to the main drum and the auxiliary drum, which specifically includes:

[0017] After the on-site construction work is completed, the main drum lifts the pipe to the continuous pipe joint, places the continuous pipe at the welding joint on the butt welding operation platform and fixes it, cuts the continuous pipe from the welding point with a cutter, and removes the main drum;

[0018] The continuous pipe end with a retractable connector on the secondary drum is pulled out by a crane, fixed on the butt welding work platform, and the pipes are butt-jointed through the retractable connector;

[0019] Open the pipe reverser and rewind the remaining coiled tubing onto the auxiliary drum until all the coiled tubing is pulled out of the well.

[0020] Further, the coiled tube end is straightened by using a straightening tool, specifically including:

[0021] Use straightening equipment to perform fine straightening of the 5m pipe end to ensure that the straightness within 5m does not exceed 2cm, and then roughly straighten the oil pipe at 5-10m to facilitate placement on the butt welding work platform. After the straightening operation is completed, use a crane to fix the main and auxiliary drum continuous pipe ends on the butt welding work platform in turn and secure them.

[0022] Furthermore, the outer ends and the inner parts of the continuous pipe ends of the main and auxiliary rollers are cleaned by an internal grinding machine to ensure that there is no rust and oil on the welds. The continuous pipe ends of the two rollers are welded, specifically including:

[0023] Grind out the groove required for welding, use the internal grinder to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively, ensure that there is no rust and oil on the weld, and expose the metallic luster; fix the continuous pipe on the welding work platform for assembly, and ensure that the misalignment of the assembly is within the range of 0-0.3mm; fix the assembled continuous pipe by three-point positioning welding, and use the clamping tool to fix the cooling block on the continuous pipe at a distance of about 10mm from the weld, perform base welding and cover welding, and grind the weld with an elastic grinding wheel. First use an 80-mesh elastic grinding wheel for coarse grinding, and then use a 120-mesh elastic grinding wheel for fine grinding to ensure that the weld is smooth and bright after grinding. Remove the welding work platform, and the inspector will conduct non-destructive inspection on the welding joint. If there is no defect, it is qualified, otherwise re-welding is performed.

[0024] The beneficial effects of the present invention are as follows:

[0025] The on-site docking and lengthening method of the coiled tubing breaks through the limitation of road transportation conditions on the capacity of the coiled tubing drum, makes up for the limitation of the coiled tubing operation process due to the drum capacity being unable to meet the operating depth of ultra-long horizontal wells / ultra-deep wells, realizes the goal of transporting ultra-long coiled tubing to the well site and to the bottom of the well, and expands the implementation scope of the coiled tubing operation process.

[0026] In order to make the above contents of the present invention more clearly understood, preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the method for on-site butt joint and lengthening of continuous tubing.

[0028] Figure 2 This is a schematic diagram of the structure before the main drum is expanded.

[0029] Figure 3 It is a schematic diagram of the structure after the main drum is expanded (after the drum body and the expansion body are spliced).

[0030] Description of reference numerals:

[0031] 1. Drum body;

[0032] 2. Expansion body; 201. First arc segment; 202. First straight segment; 203. Second arc segment; 204. Second straight segment. DETAILED DESCRIPTION

[0033] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0034] It should be noted that, in the present invention, the upper, lower, left and right in the figure are regarded as the upper, lower, left and right of the on-site butt joint and lengthening operation method of the coiled tubing described in this specification.

[0035] The exemplary embodiments of the present invention are now described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0036] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0037] This embodiment relates to a method for on-site butt-jointing and lengthening of a coiled pipe, such as Figure 1 As shown, the following steps are included:

[0038] S1. Double drums are independently transported to the well, and the double drums include a main drum and a secondary drum;

[0039] S2. Extract the ends of the coiled pipes wound on the two drums respectively and connect them on site to increase the capacity of the main drum;

[0040] S3. All the coiled tubes on the auxiliary drum are transferred to the main drum to start construction;

[0041] S4. After the construction work is completed, the underground continuous pipe is rewound to the main drum and auxiliary drum;

[0042] S5. Two rollers are transported and withdrawn independently.

[0043] The double drums are transported to the well independently by using two trailers to transport the two drums independently.

[0044] The double drum includes a main drum and a secondary drum, wherein the main drum includes a drum body 1 and an expansion body 2, Figure 2 and Figure 3 The drum body 1 includes a working shaft for winding the continuous pipe, and the drum body 1 also includes rims installed at both ends of the working shaft, and the two rims have the same structure, such as Figure 2As shown, the edge of each wheel rim is a circular structure that is symmetrical about the center of the circle, which is formed by connecting the first arc segment 201, the first straight segment 202, the second arc segment 203 and the second straight segment 204 in sequence. The expansion body 2 can be detachably installed in each straight segment and can be folded and spliced ​​along the straight segment. The expansion body 2 and the drum body 1 after splicing and assembling are circular as a whole. Figure 3 .

[0045] During the transportation of the main drum, the drum body 1 needs to be hydraulically lowered first so that the high point of the wheel rim is adjusted to the minimum height above the ground to ensure that it meets the requirements for road transportation.

[0046] Main drum structure reference before expansion Figure 2 .

[0047] The structural reference of the main drum after expansion Figure 3 .

[0048] That is to say, the main drum is a two-petal expansion structure, the expansion body 2 and the drum body 1 are connected by bolts, steel ear plates are set on both sides of the drum, and round link chains and fasteners (ratchet type tightening slings) are equipped to facilitate the fixation of the drum body 1 during transportation, and a manual locking device for the outer edge of the drum body 1 is configured.

[0049] S2 extracts the ends of the continuous pipes wound on the two drums respectively and connects them on site to increase the capacity of the main drum, specifically including:

[0050] Connect the main drum to the continuous pipe operation machine to provide power, unfold the expansion body 2, make the rim of the main drum a complete circle to achieve capacity increase, hoist the double drums so that the distance between the two drums is greater than or equal to 30m, use a crane to pull out the continuous pipe ends of the two drums and place them on the ground, first use a straightening tool to straighten the continuous pipe ends of the main and auxiliary drums respectively, and then use an internal grinder to clean the outer ends and inner parts of the continuous pipe ends of the main and auxiliary drums respectively to ensure that there is no rust and oil on the welds, fix the continuous pipe ends of the main and auxiliary drums on the welding operation platform respectively, and weld the continuous pipe ends of the two drums after the joints are aligned.

[0051] Before winding the pipe around the main drum, the drum body 1 needs to be hydraulically raised to adjust the high point of the wheel rim to the maximum height above the ground to ensure that the coiled pipe capacity meets the operating length requirements.

[0052] The welding operation process is as follows: use a crane to pull out the main and auxiliary drum continuous pipes and place them on the ground, use straightening tools to straighten the ends of the continuous pipes, and after the straightening operation, follow the welding process of "appearance inspection → oil pipe cutting → groove processing → oil pipe assembly → spot welding fixation → clamping cooling block → oil pipe welding → weld grinding → post-weld inspection" to achieve double pipe butt extension.

[0053] Use straightening tools to straighten the ends of coiled pipes. The specific operations of straightening the ends of pipes are as follows:

[0054] Use straightening equipment to perform fine straightening of the 5m pipe end to ensure that the straightness within 5m does not exceed 2cm, and then roughly straighten the oil pipe at 5-10m to facilitate placement on the butt welding work platform. After the straightening operation is completed, use a crane to fix the main and auxiliary drum continuous pipe ends on the butt welding work platform in turn and secure them.

[0055] Use the internal grinding machine to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively to ensure that there is no rust and oil on the welds. Weld the continuous pipe ends of the two drums, specifically including:

[0056] Grind out the groove required for welding, use the internal grinder to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively, ensure that there is no rust and oil on the weld, and expose the metallic luster; fix the continuous pipe on the welding work platform for assembly, and ensure that the misalignment of the assembly is within the range of 0-0.3mm; fix the assembled continuous pipe by three-point positioning welding, and use the clamping tool to fix the cooling block on the continuous pipe at a distance of about 10mm from the weld, perform base welding and cover welding, and grind the weld with an elastic grinding wheel. First use an 80-mesh elastic grinding wheel for coarse grinding, and then use a 120-mesh elastic grinding wheel for fine grinding to ensure that the weld is smooth and bright after grinding. Remove the welding work platform, and the inspector will conduct non-destructive inspection on the welding joint. If there is no defect, it is qualified, otherwise re-welding is performed.

[0057] S3: All the coiled tubes on the auxiliary drum are turned over to the main drum, and the construction work is carried out, which specifically includes:

[0058] Open the pipe reverser and reverse the coiled tubing from the auxiliary drum to the main drum until only the bottom coiled tubing is left on the auxiliary drum. Stop reverse pipe reverse and then cut the tubing. Make a windable connector on the end of the bottom coiled tubing left on the auxiliary drum and use the main drum after capacity expansion and reverse pipe reverse to implement single-drum single-pipe well-entry construction.

[0059] After the construction work in step S4 is completed, the underground coiled tubing is rewound to the main drum and the auxiliary drum, which specifically includes:

[0060] After the on-site construction work is completed, the main drum lifts the pipe to the continuous pipe joint, places the continuous pipe at the welding joint on the butt welding work platform and fixes it, uses a cutting knife to cut the continuous pipe from the welding point, and removes the main drum; uses a crane to pull out the continuous pipe end with a retractable connector from the auxiliary drum, fixes it on the butt welding work platform, and completes the pipe-to-pipe docking through the retractable connector; opens the pipe reverser, rewinds the remaining continuous pipe onto the auxiliary drum, until all the continuous pipes are pulled out of the well.

[0061] The “pipe-to-pipe docking by means of a reelable connector” mentioned in S4 refers to docking the ends of the coiled pipe remaining on site after pipe cutting with the ends of the bottom coiled pipe remaining on the secondary drum, so that the remaining coiled pipe can be subsequently rewound onto the secondary drum.

[0062] The above can be summarized as follows:

[0063] Before the main drum is expanded, the pipe is wound. Two trailers independently transport the main and auxiliary double drums to the well. The main drum is turned over, the auxiliary drum (transport drum) is placed, the working platform is placed, welding operations and joint inspections are performed, the main drum is turned over to increase the capacity, the pipe is lifted and rewound around the main drum, the continuous pipe is disconnected, the pipe is lifted to the double pipe joint and disconnected, and the remaining pipe is lifted and rewound around the auxiliary drum.

[0064] That is to say, the on-site docking and lengthening method of the coiled tubing includes the independent transportation of double drums to the well, on-site main drum expansion, double-tube docking and lengthening of the tubing, single-drum single-tube downhole operation, tubing lifting and cutting, double-drum withdrawal and other process implementation processes, which are as follows:

[0065] Two trailers are used to independently transport the main and auxiliary drums to the well. The hydraulic lifting structure of the main drum is used to adjust the high point of the wheel rim to the minimum ground clearance when winding the large-diameter coiled tubing, so as to ensure that the road transportation requirements are not exceeded when transporting to the well. At the operation site, the high point of the main drum wheel rim is adjusted to the maximum ground clearance, and the coiled tubing of the two drums is butt-jointed and then wound back around the main drum. The length of the coiled tubing meets the well depth requirements for ultra-long horizontal wells / ultra-deep wells.

[0066] This on-site docking and lengthening method of continuous tubing breaks through the limitation of road transportation conditions on the capacity of continuous tubing drums, makes up for the shortcomings of continuous tubing operation technology caused by the drum capacity being unable to meet the operating depth of ultra-long horizontal wells / ultra-deep wells, realizes the goal of transporting ultra-long continuous tubing to the well site and to the bottom of the well, and expands the implementation scope of the continuous tubing operation technology.

[0067] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A method for on-site butt-jointing and lengthening of coiled tubing, characterized in that: The following steps are involved: S1. The double drum is independently transported to the well, and the double drum includes a main drum and a secondary drum, wherein the main drum includes a drum body and an expansion body, and the drum body includes a working shaft for winding the continuous pipe and rims installed at both ends of the working shaft, and the two rims have the same structure, and the edge of each rim is a quasi-circular structure symmetrical about the center of the circle formed by connecting the first arc segment, the first straight segment, the second arc segment and the second straight segment in sequence end to end, and the expansion body can be detachably installed on each straight segment and can be folded and spliced ​​along the straight segment, and the expansion body and the drum body after splicing and assembly are circular as a whole; During the transportation of the main drum, the drum body needs to be hydraulically lowered first so that the high point of the wheel rim is adjusted to the minimum height from the ground; S2. Extract the ends of the coiled pipes wound on the two drums respectively and connect them on site to increase the capacity of the main drum; S3. All the coiled tubes on the auxiliary drum are transferred to the main drum to start construction; S4. After the construction work is completed, the underground continuous pipe is rewound to the main drum and auxiliary drum; S5. Two rollers are transported and withdrawn independently.

2. The method for on-site butt-jointing and lengthening of coiled tubing according to claim 1, characterized in that: S2 extracts the ends of the continuous pipes wound on the two drums respectively and connects them on site to increase the capacity of the main drum, specifically including: Connect the main drum to the continuous pipe operation machine, unfold the expansion body, make the rim of the main drum a complete circle to achieve capacity increase, hoist the double drums so that the distance between the two drums is greater than or equal to 30m, use a crane to pull out the continuous pipe ends of the two drums and place them on the ground, first use straightening tools to straighten the continuous pipe ends of the main and auxiliary drums respectively, and then use an internal grinder to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively to ensure that there is no rust and oil on the welds, fix the continuous pipe ends of the main and auxiliary drums on the welding operation platform respectively, and weld the continuous pipe ends of the two drums after the joints are aligned.

3. The method for on-site butt-jointing and lengthening of coiled tubing according to claim 1, characterized in that: S3: All the coiled tubes on the auxiliary drum are turned over to the main drum, and the construction work is carried out, which specifically includes: Open the pipe reverser and reverse the coiled pipe from the auxiliary drum to the main drum until only the bottom coiled pipe is left on the auxiliary drum. Stop reverse pipe, cut the pipe, and make a wrap-around connector on the bottom coiled pipe end left on the auxiliary drum. The main drum after capacity expansion and pipe inversion is used to implement single-drum and single-pipe well-entry operations.

4. The method for on-site butt-jointing and lengthening of coiled tubing according to claim 3, characterized in that: After the construction work in step S4 is completed, the underground coiled tubing is rewound to the main drum and the auxiliary drum, which specifically includes: After the on-site construction work is completed, the main drum lifts the pipe to the continuous pipe joint, places the continuous pipe at the welding joint on the butt welding operation platform and fixes it, cuts the continuous pipe from the welding point with a cutter, and removes the main drum; The continuous pipe end with a retractable connector on the secondary drum is pulled out by a crane, fixed on the butt welding work platform, and the pipes are butt-jointed through the retractable connector; Open the pipe reverser and rewind the remaining coiled tubing onto the auxiliary drum until all the coiled tubing is pulled out of the well.

5. The method for on-site butt-jointing and lengthening of coiled tubing according to claim 2, characterized in that: The straightening tool is used to straighten the coiled pipe end, including: Use straightening equipment to perform fine straightening of the 5m pipe end to ensure that the straightness within 5m does not exceed 2cm, and then roughly straighten the continuous pipe at 5-10m to facilitate placement on the butt welding work platform. After the straightening operation is completed, use a crane to fix the main and auxiliary drum continuous pipe ends on the butt welding work platform in turn and secure them.

6. The method for on-site butt-jointing and lengthening of coiled tubing according to claim 2, characterized in that: Use the internal grinding machine to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively to ensure that there is no rust and oil on the welds. Weld the continuous pipe ends of the two drums, specifically including: Grind out the groove required for welding, use the internal grinder to clean the outer and inner ends of the continuous pipe ends of the main and auxiliary drums respectively, ensure that there is no rust and oil on the weld, and expose the metallic luster; fix the continuous pipe on the welding work platform for assembly, and ensure that the misalignment of the assembly is within the range of 0-0.3mm; fix the assembled continuous pipe by three-point positioning welding, and use the clamping tool to fix the cooling block on the continuous pipe at a distance of about 10mm from the weld, perform base welding and cover welding, and grind the weld with an elastic grinding wheel. First use an 80-mesh elastic grinding wheel for coarse grinding, and then use a 120-mesh elastic grinding wheel for fine grinding to ensure that the weld is smooth and bright after grinding. Remove the welding work platform, and the inspector will conduct non-destructive inspection on the welding joint. If there is no defect, it is qualified, otherwise re-welding is performed.

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