CN104929579A - Super-borehole-diameter borehole cleaning short section - Google Patents

Abstract

The invention discloses a wellbore cleaning nipple with a super diameter, which belongs to the field of oil and gas field drilling engineering, and comprises a nipple rigid body and a flexible cleaner. The outer middle area of the nipple rigid body is provided with an annular groove, and the surface of the annular groove is There are right-handed threads and left-handed threads respectively; the flexible sweeper is integrally formed on the annular groove, which consists of a flexible sweeper body sleeved on the annular groove and several groups of flexible columns distributed on the outer surface of the flexible sweeper body . The present invention can remove the cuttings deposited in directional wells, extended-reach wells and high-inclination wells, etc. resistance, a kind of over-diameter borehole cleaning nipple is specially proposed.

Description

A Borehole Sweeping Nipple with Super Bore Diameter

technical field

The invention belongs to the field of drilling engineering in oil and gas fields, and relates to a wellbore cleaning nipple for drilling directional wells, extended-reach wells, highly-inclined wells or horizontal wells and exceeding the borehole diameter.

Background technique

Oil and gas drilling and geological exploration drilling After the drilling of a hole of a size, it is necessary to carry out drilling operations to remove the micro-steps on the well wall and the debris deposited in the "big belly" hole, so that during the subsequent wireline logging operations, the logging instrument can It slides into the bottom of the wellbore by gravity, and lifts the cable to complete the logging operation. However, due to the inclination of directional wells, extended-reach wells, and highly-inclined wells, cuttings will accumulate in irregular or enlarged boreholes (such as "big belly" boreholes), which will hinder the entry of logging tools. It will lead to the failure of wireline logging operation, and may cause logging operation accidents, such as the accumulation of cuttings, which will cause the logging instrument to be stuck when it is lifted up and lowered, resulting in an accident.

Commonly used tools for well logging and drilling are helical blade swirling and rigid helical blade tools, the outer diameters of which are significantly smaller than the diameter of the original borehole. The well section with regular diameter can play a certain role, but in the well section with irregular well diameter, especially the "big belly" well section with a large diameter expansion rate, the impact force of drilling fluid is weak and the affected area is small. The outer diameters of the drilling tools are smaller than the diameter of the original borehole, and the blades or blades of the helical blade swirling and rigid helical blade tools cannot directly sweep the cuttings in the "big belly" wellbore, but only affect the surface cuttings , the removal effect of cuttings is poor, and it cannot effectively prevent and avoid the occurrence of complex accidents of logging stuck.

Contents of the invention

The purpose of the present invention is to: in order to remove the cuttings deposited in the "big belly" borehole section with a large diameter expansion rate such as directional wells, extended-reach wells and highly-inclined wells, etc. Lifting and lowering resistance, a special borehole cleaning nipple with super diameter is proposed.

The object of the invention is achieved through the following technical solutions:

A wellbore cleaning nipple with an over-diameter borehole, comprising a nipple rigid body and a flexible cleaner, the outer middle of the nipple rigid body is provided with an annular groove, and the surface of the annular groove is respectively designed with a right-handed thread and a left-handed thread; The flexible sweeper is integrally formed on the annular groove, and it is composed of a flexible sweeper body sleeved on the annular groove and several groups of flexible columns distributed on the outer surface of the flexible sweeper body; the outer diameter of the flexible sweeper body ( That is, the diameter of the root of the flexible column) is 15-40% smaller than the diameter D _H of the original wellbore (4), and the ratio of the diameter D _T of the circumference where the top of the flexible column is located to the diameter D _H of the original wellbore is: 1.2≤D _T /D _H ≤1.3. The shape of the bottom of the flexible column is a circular platform, the top surface of the circular platform is connected to the spherical surface, and the angle between the trapezoidal side DE of the bus bar of the circular platform and the axis OC is ɑ, and the angle is 8 degrees≤ɑ≤12 degrees; The tensile strength is greater than 35MPa (25°C), the compression set is less than 35% (150°C×70h), and the wear index is greater than 150.

The basic principle of the invention is: the material of the flexible sweeper is a flexible material with obvious flexibility, very strong deformability and remarkable elastic deformation. When the flexible cleaner larger than the original borehole diameter is rotated and run into the well section with regular borehole diameter, the deformable rubber column will be bent and deformed, and the borehole will be cleaned directly with pre-pressure. When it runs into the well section with irregular borehole diameter or "big belly", the elastic rubber column will stretch back and touch the well wall, which can directly clean up the debris deposited in the "big belly" wellbore. Under the action of rock, the effective removal of cuttings can be realized.

What is particularly critical is: specific and limited flexible cleaner body size, flexible column size, shape parameters, for example, specific flexible column size, can realize "big belly" wells with irregular well diameter and large diameter expansion rate The rubber cleaner can pass through the wellbore smoothly and can agitate cuttings well; when D _T /D _H > 1.3, the rubber column is too long and flexible, and the agitation effect of cuttings is poor. If the column length D _T is significantly greater than D _H , the deformation of the rubber column in the well will be too large, which will increase the frictional resistance between the rubber cleaner and the well wall and shorten the service life of the rubber column; when D _T /D _H <1.2 When the size of the rubber column is too short, the agitation depth of cuttings is too shallow, and the application range is limited. The combination of the specific flexible cleaner body size, flexible column size, and shape parameters ensures the cleaning speed, smoothness and cleaning efficiency. The combination of effects can be applied to the removal of cuttings deposited in directional wells, extended-reach wells, and highly-inclined wells and other wells with irregular diameters and "big belly" wells with a large diameter expansion rate, which are difficult in the existing technology .

In addition, the design of the annular groove of the present invention can increase the thickness of the base of the flexible sweeper. Due to the complex environment in the well, the wellbore cleaning short joint needs to move up and down and rotate, and the wellbore cleaning short joint suffers from large friction resistance. In order to increase the bonding strength and reliability between the flexible cleaner body and the rigid body of the short joint, this paper The surface of the annular groove of the inventive nipple rigid body is processed with left-handed and right-handed threads. When the flexible cleaner is integrally formed on the rigid body of the nipple, the flexible cleaner and the rigid body of the nipple will form corresponding right-handed and left-handed nesting, which increases the bonding area between the rigid body of the nipple and the flexible cleaner. At the same time, since the left and right helical nesting coupling can form a reliable interlock, it can effectively prevent the relative movement between the rigid body of the nipple and the flexible cleaner (including relative axial movement and rotation). Therefore, the nipple rigid body of the present invention is firmly bonded to the flexible cleaner, has high reliability and long service life. Further, the integral formation of several groups of flexible columns on the outer surface of the flexible cleaner body can reduce the complexity of mold design, simplify the processing technology, and improve the overall strength of the flexible cleaner.

Further, the rubber wear index is greater than 150, the compression set is less than 35% (150°C×70h), and the tensile strength is greater than 35MPa (25°C), which can make the rubber column have better strength under high temperature conditions at the bottom of the well , Elasticity and service life - the parameters in the brackets are the test conditions of the results of the parameters before the brackets; the shape parameters of the flexible column can further reduce the flexibility of the rubber column on the one hand, and on the other hand, it is conducive to the release of the rubber column and reduce the rubber cleaner processing difficulty.

As an option, at least three threads are designed on the surface of the annular groove of the rigid body of the nipple, and the multiple threads are arranged alternately in the manner of right-handed-left-handed-right-handed or left-handed-right-handed-left-handed.

In the above scheme, the interlocking arrangement of multi-segment threads with opposite directions of rotation locally encrypts the reliable interlocking of the left and right spiral nested couplings, which can increase the consolidation strength and reliability between the rigid body of the pup joint and the body of the rubber cleaner, and prevent There is relative motion between the sub rigid body and the rubber cleaner.

As an option, the flexible columns are evenly distributed along the circumference of the flexible cleaner body, and arranged in multiple groups at equal distances in the axial direction.

In the above solution, as a preference, the uniform circumferential arrangement of the rubber columns can make the wellbore cleaning nipples evenly stressed and prevent eccentricity; the axial equidistant multi-group arrangement can enhance the overall cleaning effect of the tool.

As a further option, the flexible material used in the flexible cleaner is a polymer material.

As a further option, the flexible material used in the flexible cleaner is rubber.

The above-mentioned main scheme of the present invention and its further options can be combined freely to form multiple schemes, all of which are applicable and claimed schemes of the present invention: as in the present invention, each selection can be combined with other selections arbitrarily, and those skilled in the art After understanding the solution of the present invention, according to the prior art and common knowledge, it can be understood that there are various combinations, all of which are technical solutions to be protected by the present invention, and are not exhaustive here.

Beneficial effects of the present invention: the borehole cleaning nipple exceeding the size of the original borehole can directly clean the debris deposited in boreholes with irregular borehole diameters and “big belly” boreholes with a large borehole diameter expansion rate, and carry rocks in the drilling fluid circulation Under the action, it can realize the effective removal of cuttings, improve the cleanliness of the wellbore, reduce the resistance of the logging instrument to run in, and avoid the accident of the logging instrument getting stuck during the well operation. Moreover, the nipple rigid body of the present invention is firmly bonded to the rubber cleaner, has strong reliability and long service life.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Fig. 2 is a cross-sectional view of the present invention running into a drilled wellbore.

Fig. 3 is a sectional view of A-A in Fig. 1 .

Fig. 4 is a schematic diagram of right-handed and left-handed two-stage threads in the middle part of the sub rigid body.

Numbers in the figure: 1—Pub rigid body, 1a—Left-handed thread, 1b—Right-handed thread, 2—Rubber cleaner, 2a—Rubber cleaner body, 2b—Rubber column, 3—"Big belly" borehole, 4— The original wellbore.

Detailed ways

The following non-limiting examples illustrate the invention.

The present invention provides a wellbore cleaning nipple with a super diameter, as shown in Figures 1-4, which consists of a nipple rigid body 1 and a rubber cleaner 2 (the flexible cleaner is preferably made of polymer materials, such as this rubber in the embodiment), the outer diameter of the middle part of the nipple rigid body 1 is smaller than the outer diameter of both ends, thereby forming an annular groove surrounding the outer surface of the nipple rigid body 1 in the circumferential direction, and the surface of the annular groove is respectively designed with right-handed threads 1a and Left-hand thread 1b (as shown in Figure 4). The rubber cleaner 2 is integrally vulcanized on the nipple rigid body 1. The rubber cleaner body 2a is integrally formed, and there are several groups of rubber columns 2b (as shown in Figure 2). The diameter D _T of the circle where the top of the rubber column 2b is located is greater than the diameter of the original wellbore 4 D _H , specifically, the ratio of the diameter D _T of the circumference where the top of the rubber column 2b is located to the diameter D _H of the original wellbore 4 is: 1.2≤D _T /D _H ≤1.3. The outer diameter of the rubber cleaner body 2a (that is, the diameter of the root of the rubber column) is 15-40% smaller than the diameter of the original wellbore 4 . The shape of the middle part of the rubber column 2b is a circular platform, and the top surface of the circular platform is connected to the spherical surface (as shown in Figure 1-3). The angle between the trapezoidal side DE of the busbar of the circular platform and the axis OC is ɑ, and the angle is 8 degrees≤ɑ≤12 degrees. The rubber used in the rubber cleaner 2 has a tensile strength greater than 35MPa (25°C), a compression set of less than 35% (150°C×70h), and an abrasion index greater than 150. Preferably, at least three sections of threads are designed on the outer surface of the middle part of the sub rigid body, and the multiple sections of threads are arranged alternately in the manner of right-handed-left-handed-right-handed or left-handed-right-handed-left-handed. The rubber columns 2b are evenly distributed along the circumference of the rubber cleaner body 2a, and are arranged in multiple groups at equal distances in the axial direction (as shown in Figure 1-3).

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (5)

1. the well cleaning pipe nipple of a super hole diameter, it is characterized in that: comprise pipe nipple rigid body (1) and flexible sweeper (2), described pipe nipple rigid body (1) appearance central region is provided with cannelure, and this cannelure surface is designed with right-handed thread (1a) and left hand thread (1b) respectively; Described flexible sweeper (2) entirety is shaped on this cannelure, and it is made up of the flexible sweeper body (2a) be placed on cannelure and the apparent some groups of flexible columns (2b) of flexible sweeper body (2a) that distribute; Described flexible sweeper body (2a) external diameter is less than former well (4) diameter D _h15 ~ 40%, flexible column (2b) capital place circle diameter D _twith former well (4) diameter D _hratio be: 1.2≤D _t/ D _h≤ 1.3, described flexible column (2b) base profile is round platform, and this round platform end face connects with sphere, and round platform bus trapezoidal side DE and its axes O C angle are ɑ, its angle 8 degree≤ɑ≤12 degree; The hot strength of described flexible sweeper (2) flexible material used is greater than 35MPa (25 DEG C), and compression set amount is less than 35% (150 DEG C × 70h), and abrasion index is greater than 150.

2. the well cleaning pipe nipple of super hole diameter as claimed in claim 1, it is characterized in that: 3 sections of screw threads are at least designed on the surface of described pipe nipple rigid body (1) cannelure, and this multistage screw thread is with the alternate layout of mode of d-l-dextrorotation or left-handed-d-l.

3. the well cleaning pipe nipple of super hole diameter as claimed in claim 1, is characterized in that: described flexible column (2b) is uniformly distributed along flexible sweeper body (2a) circumference, axially equidistantly organizes arrangement more.

4. the well cleaning pipe nipple of the super hole diameter as described in claim 1,2 or 3, is characterized in that: described flexible sweeper (2) flexible material used is macromolecular material.

5. the well cleaning pipe nipple of super hole diameter as claimed in claim 4, is characterized in that: described flexible sweeper (2) flexible material used is rubber.