CN107740680B - A wellbore cleaning functional drill pipe - Google Patents

Abstract

The invention provides a wellbore cleaning functional drill pipe, wherein the pipe body is welded and connected with the inner threaded joint and the outer threaded joint respectively, and there is a welding seam at the welding place between the pipe body and the inner threaded joint and the outer threaded joint; A thickening section is set at the position, the two ends where the thickening section and the pipe body intersect are respectively machined with a conical section, and the middle of the thickening section is a cylindrical section; the internal thread joint and the external thread joint are respectively processed with internal threads and external threads that can cooperate with each other. The advantages are: the rotation of the drill pipe disturbs the drilling fluid, which changes the flow state of the well fluid and improves the rock-carrying ability of the drilling fluid; due to the disturbance of the drill pipe, the cuttings deposited at the bottom of the wellbore are disturbed and enter a turbulent state. The drilling fluid is brought out of the wellbore to clean the wellbore, effectively reduce the problems of sand settling, drill string wear resistance and supporting pressure during the drilling process, and reduce the short trip of the drill string and the mud circulation flushing operation. time and reduce the risk of complex accidents downhole.

Description

A wellbore cleaning functional drill pipe

technical field

The invention relates to the field of wellbore drill pipes, in particular to a wellbore cleaning functional drill pipe.

Background technique

Drill pipe is an important tool in oil and gas exploration and development. A single drill pipe is connected by a drill pipe joint to form a whole drill string. The drill string is the circulation channel of the high-pressure drilling fluid. The high-pressure drilling fluid lubricates and cools the drill bit, and takes away the broken cuttings of the drill bit. The conventional drill string does not have the function of helping the drilling fluid to carry rock. Therefore, in the construction of horizontal wells, especially horizontal wells with long horizontal sections and extended-reach wells, there are often supporting pressure, large drill string wear resistance, and even Due to the instability of the wellbore, a large amount of cuttings will be piled up and moved, and complex downhole accidents such as the blockage of the drill string will occur, and even the drill string will be buried, resulting in drilling failure. The reason is that the cuttings will migrate for a long distance in the water well section. Due to the action of gravity and the limitation of the rock-carrying ability of the drilling fluid, the cuttings will gradually sink during the migration, and finally sink to the bottom of the wellbore, forming For the cuttings bed at the bottom of the wellbore, as the thickness of the cuttings bed increases, the mud channel will become smaller, the mud carrying capacity will further decrease, the thickness of the cuttings bed will further increase, and the supporting pressure and wear resistance of the drill string will increase. The risk of complex downhole accidents such as sticking of the drill string increases.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a wellbore cleaning functional drill pipe in order to solve the deficiencies of the prior art.

The new technical scheme of the present invention is: a wellbore cleaning functional drill pipe, comprising a pipe body, an inner threaded joint and an outer threaded joint, wherein the pipe body is respectively welded and connected with the inner threaded joint and the outer threaded joint, and the pipe body and the inner threaded joint are respectively welded and connected. There is a weld at the welding place with the external threaded joint; a thickened section is set in the middle of the pipe body, the two ends where the thickened section intersects with the pipe body are respectively machined with a tapered section, and the middle of the thickened section is a cylindrical section; the internal threaded joint and the external The threaded joints are respectively processed with internal threads and external threads which can be matched with each other.

The outer diameter of the thickened section is 25.4-50.8 mm smaller than the outer diameter of the inner threaded joint.

The length of the thickened section is 1800-2200m.

The conical surface taper of the conical section on the thickened section is 1:14~1:18.

The length of the cylindrical section of the thickened section is 220-280 mm, and the intersection of the cylindrical section and the thickened section body is processed into a tapered surface, and the taper is 13-18°.

The tapered sections on both sides are respectively machined with 3 equally divided spiral grooves, and the positions and directions of the 3 equally divided spiral grooves on the tapered sections on both sides are specular reflection distribution with the cylindrical section as the center. .

The diameter of the bottom of the spiral groove is 6-10mm larger than the outer diameter of the pipe, and the width of the groove is 1/5-1/7 of the circumference.

Three equally divided axial grooves are machined on the cylindrical section, and the positions of the grooves on the circumference are consistent with the spiral grooves.

The inner threaded joint and the outer threaded joint are respectively machined with 4 wear-resistant strips, and each wear-resistant strip has a width of 19.1-25.4 mm and a hardness greater than HRC56.

The pipe body, the inner threaded joint and the outer threaded joint can be integrally processed.

The beneficial effects of the present invention are: after the present invention is connected to the drill string, the structure design of the thickened section in the middle of the drill pipe is used, so that when the laminar drilling fluid passes through the drill pipe, the drilling is disturbed due to the rotation of the drill pipe. The flow state of the drilling fluid changes from laminar flow to turbulent flow, thereby improving the rock-carrying ability of the drilling fluid. At the same time, due to the disturbance of the drill pipe, the cuttings deposited at the bottom of the wellbore are disturbed, enter the turbulent drilling fluid and are carried out of the wellbore, thereby cleaning the wellbore and effectively reducing the drilling process. It can reduce the problems of sand settling, drill string wear resistance and supporting pressure, reduce the short trip of the drill string, the mud circulation cleaning operation time and reduce the risk of complex downhole accidents. The wellbore cleaning functional drill pipe is suitable for drilling operations under various complex conditions, especially for horizontal wells and extended reach wells with long horizontal sections.

Description of drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a schematic structural diagram of a welded wellbore cleaning functional drill pipe.

FIG. 3 is a schematic structural diagram of the middle section of the wellbore cleaning function drill pipe.

Among them: 1 is internal thread, 2 is internal thread joint, 3 is pipe body, 4 is thickened section, 5 is cylindrical section, 6 is conical section, 7 is external thread joint, 8 is external thread, 9 is wear-resistant Belt, 10 is a weld, 11 is a spiral groove, 12 is a tapered surface, and 13 is an axial groove.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

A wellbore cleaning functional drill pipe, comprising a pipe body 3, an internal threaded joint 2 and an external threaded joint 7, the pipe body 3 is respectively welded and connected with the internal threaded joint 2 and the external threaded joint 7, and the pipe body 3 is connected with the internal threaded joint 2 There is a welding seam 10 at the welding place with the external threaded joint 7; a thickening section 4 is arranged in the middle of the pipe body 3, and the two ends where the thickening section 4 and the pipe body 3 intersect are respectively machined with a conical section 6, and the middle of the thickening section 4 is The cylindrical section 5; the internal thread joint 2 and the external thread joint 7 are respectively machined with an internal thread 1 and an external thread 8 that can cooperate with each other.

The outer diameter of the thickened section 4 is 25.4-50.8 mm smaller than the outer diameter of the female threaded joint 2 .

The length of the thickened section 4 is 1800-2200m.

The taper of the tapered surface 12 of the tapered section 6 on the thickened section 4 is 1:14~1:18.

The length of the cylindrical section 5 of the thickened section 4 is 220-280 mm, and the intersection of the cylindrical section 5 and the main body of the thickened section 4 is processed into a tapered surface 12 with a taper of 13-18°.

The tapered sections 6 on both sides are respectively machined with three equally divided helical grooves 11 , and the position and direction of the three equally divided helical grooves 11 on the tapered sections 6 on both sides are based on the cylindrical section 5 . The center is specularly distributed.

The diameter of the bottom spiral groove 11 is 6-10 mm larger than the outer diameter of the pipe body 3, and the groove width is 1/5-1/7 of the circumference.

Three equally divided axial grooves 13 are machined on the cylindrical section 5 , and the positions of the grooves on the circumference are consistent with the spiral grooves 11 .

The inner threaded joint 2 and the outer threaded joint 7 are respectively machined with four wear-resistant belts 9, and the width of each wear-resistant belt 9 is 19.1-25.4 mm, and the hardness is greater than HRC56.

The pipe body 3, the inner threaded joint 2 and the outer threaded joint 7 can be integrally processed.

Claims (2)

1. A wellbore cleaning functional drill pipe, comprising a pipe body (3), an inner threaded joint (2) and an outer threaded joint (7), characterized in that: the pipe body (3) and the inner threaded joint (2) are respectively It is connected with the external threaded joint (7) by welding, and the pipe body (3) is welded with the internal threaded joint (2) and the external threaded joint (7) with a welding seam (10); 4), the outer diameter of the thickened section (4) is 25.4~50.8mm smaller than the outer diameter of the female threaded joint (2), and the length of the thickened section (4) is 1800~2200mm; (4) A cylindrical section (5) is located in the middle, and two ends where the thickened section (4) intersects with the pipe body (3) are respectively machined with a conical section (6). The cylindrical section (5) and the conical section are Between (6) is the body of the thickened section (4), the tapered section (6) with a smaller outer diameter is close to the cylindrical section (5), and the tapered sections (6) at both ends are machined with three equal sections. The position and direction of the spiral grooves (11) on the tapered section (6) are divided into three equal sections, and the position and direction of the cylindrical section (5) are centered on the mirror reflection distribution. The bottom diameter of the spiral groove (11) is 6~10mm larger than the outer diameter of the pipe body (3), and the width of the spiral groove (11) is 1/5~1/7 of the circumference. The taper of the conical surface of the conical section (6) is 1:14~1:18; the cylindrical section (5) is machined with three equally divided axial grooves (13), and the axial grooves (13) are The position on the circumference is consistent with the spiral groove (11), the length of the cylindrical section (5) of the thickened section (4) is 220~280mm, and the intersection of the cylindrical section (5) and the thickened section (4) body is processed. The taper surface (12) is formed into a tapered surface (12), and the taper is 13°~18°; the internal thread joint (2) and the external thread joint (7) are respectively machined with an internal thread (1) and an external thread (8) that can cooperate with each other. The inner threaded joint (2) and the outer threaded joint (7) are respectively machined with four wear-resistant strips (9), and each wear-resistant strip (9) has a width of 19.1-25.4 mm and a hardness greater than HRC56. 2. A wellbore cleaning functional drill pipe according to claim 1, characterized in that: the pipe body (3), the inner threaded joint (2) and the outer threaded joint (7) can be processed as a whole. to make.

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