Rigid centralizer for measurement-while-drilling instrument

Abstract

The invention relates to the technical field of measurement-while-drilling instruments for petroleum drilling, and discloses a rigid centralizer for a measurement-while-drilling instrument. A first centralizer sub-body and a second centralizer sub-body are sequentially arranged on a mandrel of the measurement-while-drilling instrument in a sleeving mode in the axial direction, one end of the first centralizer sub-body is connected to the second centralizer sub-body, and the other end of the first centralizer sub-body is connected to the second centralizer sub-body; the centering property of the mandrel is effectively ensured, so that the load distribution is more uniform, and the eccentric wear problem can be effectively reduced; the first centralizer sub-body and the second centralizer sub-body are made of metal materials, so that the anti-erosion capacity is higher, and the centralizer can be applied to a high-temperature and high-pressure measurement-while-drilling instrument and meet the production requirement of a high-temperature and high-pressure development well.

Description

Technical Field

[0001] The invention relates to the technical field of measurement while drilling instruments for oil well drilling, in particular to a rigid centralizer used for the measurement while drilling instruments. Background Art

[0002] In the mandrel drill collar structure in the field of measurement while drilling instruments, the stabilizer is generally an indispensable component, and its main function is to keep the mandrel centered and ensure the accuracy of the measurement while drilling parameters. In general, the overall structure is adopted in which the base is rigid metal and the straightening edge is rubber. By arranging multiple straighteners at a certain distance, the centering of the mandrel is achieved, thereby ensuring the accuracy of the measurement while drilling parameters. In practical applications, the rubber straightening edge part often suffers from mud erosion damage, eccentric wear failure and other problems. In particular, in high-temperature and high-pressure wells, the increase in comprehensive loads such as vibration and impact will further aggravate the above problems of the straightener, thereby affecting the accuracy of the measurement while drilling parameters and failing to meet the field application needs of future deep formation development. Therefore, it is necessary to design a rigid straightener for measurement while drilling instruments to meet the needs of field applications in response to the problems of the current straightener and to meet the needs of high-temperature and high-pressure well development. Summary of the invention

[0003] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a rigid stabilizer for a measurement while drilling instrument to solve the technical problems of mud erosion damage, eccentric wear failure and low centering performance of the rubber centralizing edge part in the prior art.

[0004] The present invention is achieved through the following technical solutions:

[0005] A rigid centralizer for a while drilling measurement instrument comprises a first centralizer sub-body and a second centralizer sub-body, wherein the first centralizer sub-body and the second centralizer sub-body are annular structures, and the first centralizer sub-body and the second centralizer sub-body are made of metal. The first centralizer sub-body and the second centralizer sub-body are sequentially sleeved on a core shaft of the while drilling measurement instrument along an axial direction, and one end of the first centralizer sub-body is connected to the second centralizer sub-body.

[0006] Preferably, the first centralizer sub-body and the second centralizer sub-body are perpendicular to the centralizing direction of the mandrel.

[0007] Preferably, the first centralizer sub-body and the second centralizer sub-body are snap-connected at opposite sides, and the other ends of the first centralizer sub-body and the second centralizer sub-body are both chamfered.

[0008] Preferably, the shaft diameter of the core shaft is set corresponding to the ring diameters of the first centralizer sub-body and the second centralizer sub-body.

[0009] Preferably, the first centralizer sub-body and the second centralizer sub-body have the same structure.

[0010] Furthermore, the first centralizer sub-body includes a first centralizer base and a second centralizer base, the first centralizer base and the second centralizer base are relatively buckled to form an annular structure, and the connecting ends of the first centralizer base and the second centralizer base are mutually connected and locked.

[0011] Furthermore, the first centralizer base is provided with a first chamfer at one end along the axial direction, which is used to be tightly attached to the outer wall of the core shaft after being connected to the second centralizer base, and a first clamping groove is provided at the other end, which is used to clamp the second centralizer sub-body after being connected to the second centralizer base. First centralizer base has first centralizing edges arranged opposite to each other on both side edges along the circumferential direction, and first drainage cone surfaces are provided at both ends of the first centralizing edge. A plurality of first countersunk holes are provided on the first centralizing edge, which are used to be fixed by screws after being matched with the connecting end of the second centralizer base.

[0012] Furthermore, the second centralizer base is arranged corresponding to the two ends of the first centralizer base, wherein one end of the second centralizer base along the axial direction is provided with a second chamfer, which is used to be close to the outer wall of the core shaft after being connected to the first centralizer base, and the other end is provided with a second clamping groove; it is used to clamp the second centralizer sub-body after being connected to the first centralizer base, and the second centralizer base is provided with second centralizing edges on both side edges along the circumferential direction, and second drainage cone surfaces are provided on both sides of the second centralizing edge, and a plurality of threaded holes are provided on the second centralizing edge, which are used to be connected with the first centralizing edge by screws after being assembled.

[0013] Furthermore, a locking plate groove is provided on the first straightening edge, and the locking plate groove and a plurality of first countersunk holes are respectively provided on the two side surfaces of the first straightening edge, wherein the two side surfaces are vertically arranged, a locking plate is inserted into the locking plate groove, and the locking plate is clamped on a plurality of screws.

[0014] Furthermore, both ends of the locking plate are interference fit surfaces, and a plurality of disassembly holes are provided on the locking plate, the number of the plurality of disassembly holes corresponds to the number of screws in the first countersunk hole, and the plurality of disassembly holes are correspondingly clamped on the plurality of screws.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] The present invention provides a rigid centralizer for a measurement while drilling instrument. A first centralizer sub-body and a second centralizer sub-body are sequentially inserted into a core shaft of the measurement while drilling instrument along an axial direction, and one end of the first centralizer sub-body is connected to the second centralizer sub-body, thereby effectively ensuring the centering of the core shaft, making the load distribution more uniform, and effectively reducing the problem of eccentric wear. The first centralizer sub-body and the second centralizer sub-body are made of metal material, so that the erosion resistance is stronger, and the instrument can be applied to a high-temperature and high-pressure measurement while drilling instrument to meet the production needs of high-temperature and high-pressure development wells.

[0017] Furthermore, the first centralizer sub-body and the second centralizer sub-body are perpendicular to the centralizing direction of the mandrel, so that the mandrel is centralized up, down, left, and right in the centralizing area, making the load distribution more uniform, effectively reducing the problem of eccentric wear, and ensuring the centrality of the mandrel.

[0018] Furthermore, the first centralizer sub-body and the second centralizer sub-body are snap-connected on opposite sides, and the first centralizer sub-body and the second centralizer sub-body adopt a split structure, which is easy to assemble. The other ends of the first centralizer sub-body and the second centralizer sub-body are both chamfered, so that the first centralizer sub-body and the second centralizer sub-body are tightly fitted to the surface of the core shaft, ensuring the centering of the core shaft.

[0019] Furthermore, the first centralizer sub-body includes a first centralizer base and a second centralizer base, the first centralizer base and the second centralizer base are relatively buckled to form an annular structure, the connecting ends of the first centralizer base and the second centralizer base are mutually connected and locked, the first centralizer sub-body and the second centralizer sub-body are both formed by assembling two groups of centralizer bases, and can be effectively buckled on the surface of the core shaft, thereby ensuring the centering of the core shaft.

[0020] Furthermore, the first centralizing edges on both sides of the first centralizer base and the second centralizing edges on both sides of the second centralizer base are fixed by a plurality of screws, so that the centralizer on the mandrel is more tightly fastened, thereby improving the centralizing effect of the mandrel.

[0021] Furthermore, a locking plate groove is also provided on the first righting edge, and the locking plate groove and a plurality of first countersunk holes are respectively on the two side surfaces of the first righting edge, wherein the two side surfaces are vertically arranged, and a locking plate is inserted into the locking plate groove, and the locking plate is clamped on a plurality of screws. The locking plate can prevent the screws from loosening and falling out, and prevent the drilling fluid from eroding the screws. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a rigid centralizer for a measurement while drilling instrument in the present invention;

[0023] Figure 2 The left side view of a rigid centralizer for a drilling measurement instrument in the present invention

[0024] Figure 3 Schematic diagram of the structure of the first centralizer base in the present invention

[0025] Figure 4 Schematic diagram of the structure of the second centralizer base in the present invention

[0026] Figure 5 Schematic diagram of the locking plate structure in the present invention

[0027] In the figure: 1 is the first centralizer base; 2 is the screw; 3 is the locking plate; 4 is the second centralizer base; 5 is the core shaft; 6-the first centralizer sub-body; 7 is the second centralizer sub-body; 1-1 is the first chamfer; 1-2 is the first drainage cone surface; 1-3 is the first countersunk hole; 1-4 is the locking plate groove; 1-5 is the first centralizing edge; 1-6 is the first clamping groove; 3-1 is the interference fit surface; 3-2 is the disassembly hole; 4-1 is the second chamfer; 4-2 is the second drainage cone surface; 4-3 is the threaded hole; 4-4 is the second centralizing edge; 4-5 is the second clamping groove. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0031] The object of the present invention is to provide a rigid centralizer for a measurement while drilling instrument to solve the technical problems in the prior art that the rubber centralizer edge portion is often damaged by mud erosion, fails due to eccentric wear and has low centering performance.

[0032] See also Figure 1 In one embodiment of the present invention, a rigid centralizer for a while drilling measurement instrument is provided, including a first centralizer sub-body 6 and a second centralizer sub-body 7, wherein the first centralizer sub-body 6 and the second centralizer sub-body 7 are annular structures, and the first centralizer sub-body 6 and the second centralizer sub-body 7 are made of metal. The first centralizer sub-body 6 and the second centralizer sub-body 7 are sequentially sleeved on the core shaft 5 of the while drilling measurement instrument along the axial direction, and one end of the first centralizer sub-body 6 is connected to the second centralizer sub-body 7.

[0033] Specifically, according to Figure 2 As shown, the first centralizer sub-body 6 and the second centralizer sub-body 7 are perpendicular to the centralizing direction of the mandrel 5, so that the mandrel is centralized up, down, left, and right in the centralizing area, making the load distribution more uniform, effectively reducing the problem of eccentric wear, and ensuring the centrality of the mandrel.

[0034] Specifically, the first centralizer sub-body 6 and the second centralizer sub-body 7 are connected by snapping at opposite sides, and the other ends of the first centralizer sub-body 6 and the second centralizer sub-body 7 are both chamfered.

[0035] Specifically, the shaft diameter of the core shaft 5 is set corresponding to the ring diameters of the first centralizer sub-body 6 and the second centralizer sub-body 7 .

[0036] Specifically, the first centralizer sub-body 6 and the second centralizer sub-body 7 have the same structure.

[0037] Among them, the first centralizer sub-body 6 includes a first centralizer base 1 and a second centralizer base 4, the first centralizer base 1 and the second centralizer base 4 are relatively buckled to form a ring structure, and the connecting ends of the first centralizer base 1 and the second centralizer base 4 are mutually connected and locked.

[0038] Among them, according to Figure 3 As shown, the first centralizer base 1 is provided with a first chamfer 1-1 at one end along the axial direction, which is used to be close to the outer wall of the core shaft 5 after being connected with the second centralizer base 4, and a first clamping groove 1-6 is provided at the other end, which is used to clamp the second centralizer sub-body 7 after being connected with the second centralizer base 4. The first centralizer base 1 is provided with first centralizing edges 1-5 on both sides of the edge along the circumferential direction, and first drainage cone surfaces 1-2 are provided at both ends of the first centralizing edge 1-5. A plurality of first countersunk holes 1-3 are provided on the first centralizing edge 1-5, which are used to be fixed by screws 2 after being matched with the connecting end of the second centralizer base 4.

[0039] Among them, according to Figure 4As shown, the second centralizer base 4 is arranged corresponding to the two ends of the first centralizer base 1, wherein one end of the second centralizer base 4 along the axial direction is provided with a second chamfer 4-1, which is used to be closely attached to the outer wall of the core shaft 5 after being connected with the first centralizer base 1, and the other end is provided with a second clamping groove 4-5; used to clamp the second centralizer sub-body 7 after being connected with the first centralizer base 1, the second centralizer base 4 is provided with second centralizing edges 4-4 on both sides of the circumferential direction, and second drainage cone surfaces 4-2 are provided on both sides of the second centralizing edges 4-4, and a plurality of threaded holes 4-3 are provided on the second centralizing edges 4-4, which are used to be connected to the first centralizing edges 1-5 by screws 2 after being assembled.

[0040] Specifically, a locking plate groove 1-4 is also provided on the first straightening edge 1-5, and the locking plate groove 1-4 and a plurality of first countersunk holes 1-3 are respectively on the two side surfaces of the first straightening edge 1-5, wherein the two side surfaces are vertically arranged, and a locking plate 3 is inserted into the locking plate groove 1-4, and the locking plate 3 is clamped on a plurality of screws 2.

[0041] Specifically, according to Figure 5 As shown, both ends of the locking plate 3 are interference fit surfaces, and a plurality of disassembly holes 3-2 are provided on the locking plate 3. The number of the plurality of disassembly holes 3-2 corresponds to the number of screws 2 in the first countersunk hole 1-3, and the plurality of disassembly holes 3-2 are correspondingly clamped on the plurality of screws 2.

[0042] Example

[0043] The present embodiment provides a rigid centralizer for a measurement while drilling instrument, comprising a first centralizer sub-body 6 and a second centralizer sub-body 7 of the same structure, wherein the first centralizer sub-body 6 comprises a first centralizer base 1 and a second centralizer base 4, the first centralizer base 1 and the second centralizer base 4 are connected and fixed using six screws 2; the second centralizer sub-body 7 comprises the first centralizer base 1 and the second centralizer base 4, the first centralizer base 1 and the second centralizer base 4 are connected and fixed using six screws 2; and then the four locking plates 3 are gently knocked into the corresponding grooves.

[0044] The stabilizer has four circumferentially arranged stabilizing edges, which makes the load distribution more uniform and can effectively reduce the problem of eccentric wear. This split structure can simplify the processing technology and improve production efficiency. It also has a simple structure and is easy to disassemble and assemble, which is more conducive to promotion and application. When installing the stabilizer on the drilling measurement instrument, it can generally be arranged at intervals of one meter. A small gap is used with the inner diameter of the drill collar for easy installation, and then it is fixed by pressing at the top to achieve the centering effect of the entire instrument.

[0045] The first centralizer base 1 is made of all metal, with a first chamfer 1-1 at one end and a slot 1-6 at the other end. The first centralizing edges 1-5 are arranged at two locations at 180°. The first centralizing edges 1-5 are provided with first drainage cone surfaces 1-2 at both ends, three first countersunk holes 1-3 for installing screws 2, and locking plate grooves 1-4 for installing locking plates 3.

[0046] The second centralizer base 4 is made of all metal, with a second chamfer 4-1 at one end and a second slot 4-5 at the other end. The second centralizing edges 4-4 are arranged at two locations at 180 degrees, and both ends of the second centralizing edges 4-4 are provided with drainage cones 4-2 and three threaded holes 4-3 for connection.

[0047] The locking piece 3 is interference fit with the locking piece slot 1-4 on the first centralizer base 1, and has interference fit surfaces 3-1 at both ends and three disassembly holes 3-2. The locking piece can prevent the screw 2 from loosening and falling out, and prevent the drilling fluid from eroding the screw 2.

[0048] In summary, the present invention provides a rigid centralizer for a measurement while drilling instrument. By sequentially inserting a first centralizer sub-body and a second centralizer sub-body into the core shaft of the measurement while drilling instrument along the axial direction, one end of the first centralizer sub-body is connected to the second centralizer sub-body, which effectively ensures the centering of the core shaft, makes the load distribution more uniform, and can effectively reduce the problem of eccentric wear; the first centralizer sub-body and the second centralizer sub-body are made of metal material, so that the erosion resistance is stronger, and the measurement while drilling instrument can be applied to high-temperature and high-pressure measurement while drilling to meet the production needs of high-temperature and high-pressure development wells.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A rigid centralizer for a measurement while drilling instrument, It is characterized in that The invention comprises a first centralizer sub-body (6) and a second centralizer sub-body (7), wherein the first centralizer sub-body (6) and the second centralizer sub-body (7) are annular structures, the first centralizer sub-body (6) and the second centralizer sub-body (7) are made of metal, the first centralizer sub-body (6) and the second centralizer sub-body (7) are sequentially sleeved on a core shaft (5) of a while drilling measurement instrument along an axial direction, and one end of the first centralizer sub-body (6) is connected to the second centralizer sub-body (7).

2. A rigid centralizer for a measurement while drilling instrument according to claim 1, It is characterized in that The first centralizer sub-body (6) and the second centralizer sub-body (7) are perpendicular to the centralizing direction of the core shaft (5).

3. A rigid centralizer for a measurement while drilling instrument according to claim 1, It is characterized in that The first centralizer sub-body (6) and the second centralizer sub-body (7) are connected by snapping at opposite sides, and the other ends of the first centralizer sub-body (6) and the second centralizer sub-body (7) are both chamfered.

4. A rigid centralizer for a measurement while drilling instrument according to claim 1, It is characterized in that The shaft diameter of the core shaft (5) is set corresponding to the ring diameters of the first centralizer sub-body (6) and the second centralizer sub-body (7).

5. A rigid centralizer for a measurement while drilling instrument according to claim 1, It is characterized in that The first centralizer sub-body (6) and the second centralizer sub-body (7) have the same structure.

6. A rigid centralizer for a measurement while drilling instrument according to claim 5, It is characterized in that The first centralizer sub-body (6) comprises a first centralizer base (1) and a second centralizer base (4), the first centralizer base (1) and the second centralizer base (4) are relatively buckled to form a ring structure, and the connecting ends of the first centralizer base (1) and the second centralizer base (4) are mutually connected and locked.

7. A rigid centralizer for a measurement while drilling instrument according to claim 6, It is characterized in that The first centralizer base (1) is provided with a first chamfer (1-1) at one end along the axial direction, which is used to be closely attached to the outer wall of the core shaft (5) after being connected to the second centralizer base (4), and a first clamping groove (1-6) is provided at the other end, which is used to clamp the second centralizer sub-body (7) after being connected to the second centralizer base (4). The first centralizer base (1) is provided with first centralizing edges (1-5) on both sides of the edge along the circumferential direction, and first drainage cone surfaces (1-2) are provided at both ends of the first centralizing edge (1-5). A plurality of first countersunk holes (1-3) are provided on the first centralizing edge (1-5), which are used to be fixed by screws (2) after being matched with the connecting end of the second centralizer base (4).

8. A rigid centralizer for a measurement while drilling instrument according to claim 7, It is characterized in that The second centralizer base (4) is arranged at two ends corresponding to the first centralizer base (1), wherein one end of the second centralizer base (4) along the axial direction is provided with a second chamfer (4-1) for being connected to the first centralizer base (1) and closely attached to the outer wall of the core shaft (5), and the other end is provided with a second clamping groove (4-5); and is used for clamping the second centralizer sub-body (7) after being connected to the first centralizer base (1). The second centralizer base (4) is provided with second centralizing edges (4-4) on both sides of the circumferential direction, and second drainage cone surfaces (4-2) are provided on both sides of the second centralizing edge (4-4). The second centralizing edge (4-4) is provided with a plurality of threaded holes (4-3) for being connected to the first centralizing edge (1-5) through screws (2) after being assembled.

9. A rigid centralizer for a measurement while drilling instrument according to claim 7, It is characterized in that The first straightening edge (1-5) is also provided with a locking plate groove (1-4), the locking plate groove (1-4) and a plurality of first countersunk holes (1-3) are respectively located on two side surfaces of the first straightening edge (1-5), wherein the two side surfaces are vertically arranged, a locking plate (3) is inserted into the locking plate groove (1-4), and the locking plate (3) is clamped on a plurality of screws (2).

10. A rigid centralizer for a measurement while drilling instrument according to claim 9, It is characterized in that Both ends of the locking plate (3) are interference fit surfaces. The locking plate (3) is provided with a plurality of disassembly holes (3-2). The number of the plurality of disassembly holes (3-2) corresponds to the number of screws (2) in the first countersunk hole (1-3). The plurality of disassembly holes (3-2) are correspondingly clamped on the plurality of screws (2).

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