An easy-to-process while-drilling electromagnetic wave resistivity instrument

Abstract

The invention discloses an electromagnetic wave resistivity instrument for drilling that is easy to process and realize, comprising an upper transfer drill collar, a frame and a lower transfer drill collar, wherein a square groove for placing a circuit board and a ring groove for placing an antenna coil are opened on the outer circle of the frame, and a wear-resistant belt is welded on the outer circle of the frame, and the wear-resistant belt is in the shape of a long strip and is located in the gaps between the multiple square grooves on the outer circle of the frame. The electromagnetic wave resistivity instrument for drilling that is easy to process and realize disclosed by the invention adopts a shell slotting method based on the consideration of reducing the pressure of circuit design, and the remaining parts are designed with corresponding structures according to the processing means that can be adopted in China, so as to achieve the same effect as foreign advanced instruments.

Description

Technical Field

[0001] The invention belongs to the field of resistivity instruments, and in particular relates to a drilling electromagnetic wave resistivity instrument in the field which is easy to process and realize. Background Art

[0002] At present, most of the mature downhole electromagnetic wave resistivity structures have the circuit and antenna separated. The antenna is on the downhole resistivity shell, and the circuit is placed in the center hole inside the shell. This structure makes the connection between the antenna and the circuit complicated, and the circuit is all installed in a pressure tube, which is not conducive to electromagnetic shielding. The patent "New Downhole Resistivity Shell" disclosed by Fan Cun et al. is of this form; the latest electromagnetic wave resistivity instrument of Baker Hughes Company abroad has grooves on the downhole resistivity shell, and the circuit is placed in the grooves. Each circuit groove is interconnected through slender deep holes. The processing of the slender deep holes in this structure is a difficult problem. It is not known how it is achieved abroad. This structure has not been patented, so further technical details are unknown. That is, the problem with the prior art is that the structure that is easy to process and realize has high requirements for circuit design, while the structure with low requirements for circuit design is difficult to process and realize domestically. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a drilling electromagnetic wave resistivity instrument which is easy to manufacture and realize.

[0004] The present invention adopts the following technical solution:

[0005] The invention discloses an electromagnetic wave resistivity instrument for drilling which is easy to process and realize. The improvement is as follows: the instrument comprises an upper transfer drill collar, a frame and a lower transfer drill collar, wherein a square groove for placing a circuit board and a ring groove for placing an antenna coil are opened on the outer circle of the frame, a wear-resistant belt is welded on the outer circle of the frame, and the wear-resistant belt is in the shape of a long strip and is located in the gap between the multiple square grooves on the outer circle of the frame; the upper and lower parts of the frame are equipped with mud flow channel conversion heads for introducing the wires in the wiring holes on the frame wall into the MWD system located in the middle of the water hole, and a pressure-bearing connector is installed at the interface of the mud flow channel conversion head , connected to the upper mud flow channel conversion head is a seven-core slip ring connector, which is connected to the telescopic short section of the MWD system, connected to the lower mud flow channel conversion head is a ten-core aviation plug, which is connected to the lower azimuth gamma short section, the upper mud flow channel conversion head is fixed to the upper part of the skeleton through the upper adapter drill collar and the lower part of the skeleton, and the lower mud flow channel conversion head is fixed to the lower part of the skeleton through the lower adapter drill collar; in addition, it also includes a pressure sensor installed at the lower part, and a hole retaining ring is installed in the corresponding mounting hole of the pressure sensor to prevent loosening.

[0006] Furthermore, in a non-working state, a thread protection head, a thread protection cap, a rubber protection cap and a protection cap are installed.

[0007] Furthermore, the upper mud flow channel conversion head includes an outwardly protruding conversion short section, on which a conversion drill collar is mounted, the conversion short section and the conversion drill collar are connected via an adjustment ring, the mud flow channel conversion head is connected at the tail of the conversion short section, and the skeleton is connected at the tail of the mud flow channel conversion head, wherein the conversion short section and the mud flow channel conversion head are connected via a screw sleeve, and a large nut is used to fix the screw sleeve to the mud flow channel conversion head.

[0008] Furthermore, the conversion short section includes a seven-core slip ring connector assembly, which is fixed to the inner hole of the main body end by a key and a wire retaining ring, and the wires at the tail of the seven-core slip ring connector assembly are connected to the pressure connector. Before the lead wires of the seven-core slip ring connector assembly are welded to the pressure connector, a polytetrafluoroethylene thin tube is first put on, and after welding, the polytetrafluoroethylene thin tube is put on the tail of the pressure connector and then poured into the epoxy resin that cures at room temperature, and after the epoxy resin is cured, the polytetrafluoroethylene thin tube is cut and then removed; the pressure connector is fixed to the main body by special-shaped parts and screws, and the upper and lower parts of the main body are sealing surfaces, and all sealing links must be strengthened by PEEK retaining rings.

[0009] Furthermore, the main parts of the mud flow channel conversion head are processed from nickel-based alloy 925, the bridge joint is used for wiring connection between the main part and the skeleton drill collar, the adjustment ring is used for error compensation between the main part and the instrument skeleton drill collar, a key is set on the main part, and three sealing surfaces are also set on the main part. All sealing links must be strengthened with PEEK retaining rings.

[0010] Furthermore, there is an inclined special-shaped hole in the mud flow channel conversion head, one end of which is connected to the slip ring, and the other end is connected to the ultra-deep hole in the drilling arm through a bridge plug. In addition, a large sealing ring is used to seal both ends of the special-shaped hole.

[0011] The beneficial effects of the present invention are:

[0012] The electromagnetic wave resistivity instrument for drilling that is easy to process and realize disclosed by the present invention adopts the method of slotting the shell based on the consideration of reducing the pressure of circuit design, and the corresponding structure of the remaining parts is designed according to the processing means that can be adopted in China, so as to achieve the same effect as that of foreign advanced instruments. Compared with the existing structure, it has three advantages: first, this structure is easy to process and realize; second, this structure has excellent electromagnetic isolation performance and is easier to design and realize the circuit; third, this structure is easy to repair. The special-shaped hole adopts the method of sealing with a bridge plug and sealing with large sealing rings at both ends to form a sealed space, so as to prevent mud from entering the special-shaped hole and separate the mud from the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the instrument of the present invention;

[0014] Figure 2 It is a schematic diagram of the structure of the upper mud flow channel conversion head in the instrument of the present invention;

[0015] Figure 3a It is a stereoscopic diagram of a conversion nipple in the instrument of the present invention;

[0016] Figure 3b It is a structural schematic diagram of the conversion short section in the instrument of the present invention;

[0017] Figure 4a It is a stereoscopic diagram of the mud flow channel conversion head in the instrument of the present invention;

[0018] Figure 4b It is a structural schematic diagram of the mud flow channel conversion head in the instrument of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] Example 1. This example discloses an electromagnetic wave resistivity instrument while drilling that is easy to process and implement. It mainly uses the influence of the medium on the propagation of electromagnetic waves to determine the properties of the medium. The electromagnetic waves emitted from the transmitting antenna pass through the stratum to reach the receiving antenna in the middle. Due to the different conductivity of the stratum, the electromagnetic waves have phase differences and amplitude differences when they reach the receiving antenna. Since different strata have different phase differences and amplitude differences, the strata can be distinguished.

[0021] The overall structure of the instrument is as follows Figure 1As shown, the instrument is mainly composed of an upper transfer drill collar 201, a skeleton 202 and a lower transfer drill collar 206, wherein the skeleton 202 is the main part, and a square groove 212 for placing a circuit board and an annular groove 204 for placing an antenna coil are opened on its outer circumference. In order to protect the square groove 212 and the annular groove 204, a wear-resistant belt 203 is welded on the outer circumference of the skeleton 202. The wear-resistant belt 203 is a long strip and is located in the gap between the multiple square grooves 212 on the outer circumference of the skeleton 202; the upper and lower parts of the skeleton 202 are equipped with mud flow channel conversion heads 207. The main function of 207 is to introduce the wires in the wiring holes 211 on the wall of the skeleton 202 into the MWD instrument located in the middle of the water eye, while not blocking the flow area of ​​the water eye. Since the assembly and maintenance of the while drilling resistivity instrument is very complicated, a pressure-bearing connector 209 is installed at the interface of the mud flow channel conversion head 207. , connected to the upper mud flow channel conversion head 207 is a seven-core slip ring connector 208, which is connected to the telescopic short section of the MWD system, and connected to the lower mud flow channel conversion head 207 is a ten-core aviation plug 210, which is connected to the lower azimuth gamma short section in actual work, the upper mud flow channel conversion head 207 is fixed by the upper adapter drill collar 201 and the upper part of the skeleton 202, and the lower mud flow channel conversion head 207 is fixed by the lower adapter drill collar 206 and the lower part of the skeleton 202; the lower part of the instrument is equipped with a pressure sensor 205, which is fixed and sealed by its own threads and sealing surfaces, and the corresponding mounting hole is equipped with a hole retaining ring to prevent loosening; the instrument is equipped with a thread protector 214, a thread protector 213, a rubber protective cap 215 and a protective cap 216 in the non-working state, all of which cannot withstand pressure, and the pressure test must be replaced with a pressure-bearing joint.

[0022] The structure of the upper mud flow channel conversion head is as follows: Figure 2 As shown in the figure (the upper and lower mud channel conversion heads have the same structure except for the electrical connector, so they are not illustrated separately), 301 is the conversion nipple, see Figure 3a , 302 is the conversion drill collar, 303 is the mud flow channel conversion head, see Figure 2 , 304 is a frame, 305 is a threaded sleeve for connecting 301 and 303, 306 is a large nut for fixing the threaded sleeve 305 on the mud flow channel conversion head 303, and 307 is an adjusting ring.

[0023] The structure of the conversion short section 301 is as follows Figure 3a, as shown in Figure 3b, 401 is a seven-core slip ring connector assembly, which is fixed to the inner hole at the end of the main body 402 by a key 404 and a steel wire retaining ring. The wire at the tail of 401 is connected to the pressure connector 410. Before the lead wire of 401 is welded to 410, a polytetrafluoroethylene thin tube is first put on. After welding, the polytetrafluoroethylene thin tube is put on the tail of 410 and then filled with room temperature curing epoxy resin 406. After the epoxy resin is cured, the polytetrafluoroethylene thin tube is cut and then removed; the pressure connector 410 is fixed to the main body 402 by a special-shaped piece 405 and a screw 407. The upper and lower surfaces of 402 are sealing surfaces, and all sealing links must be strengthened by PEEK retaining rings 403. The central wire in the wiring hole enters the telescopic short section of the MWD instrument in the middle of the water hole through the cavity inside the conversion short section through the seven-core slip ring connector assembly.

[0024] Figure 4a , 4b describes in detail Figure 2 The structure of the medium mud flow channel conversion head 303, where 501 is the main part and is planned to be processed with nickel-based alloy 925, 505 is a bridge joint for wiring connection between 501 and the instrument skeleton drill collar, 503 is an adjustment ring for error compensation between 501 and the instrument skeleton drill collar, 507 is a key for positioning, guiding and anti-rotation, and there are three sealing surfaces 502, 504 and 506 on 501. All sealing links must be reinforced with PEEK retaining rings.

[0025] There is an inclined special-shaped hole in the mud flow channel conversion head. One end of the special-shaped hole is connected to the slip ring, and the other end is connected to the ultra-deep hole in the drilling arm through a five-core bridge plug. In addition, a large sealing ring is used to seal the special-shaped hole at both ends. The special-shaped hole is sealed by a five-core bridge plug and a large sealing ring at both ends to form a sealed space to prevent mud from entering the special-shaped hole and separate the mud from the circuit.

Claims

1. An electromagnetic wave resistivity instrument while drilling that is easy to process and realize, characterized in that: The invention comprises an upper transfer drill collar, a frame and a lower transfer drill collar, wherein the outer circle of the frame is provided with a square groove for placing a circuit board and a ring groove for placing an antenna coil, and a wear-resistant belt is welded on the outer circle of the frame, and the wear-resistant belt is in the shape of a long strip and is located in the gap between the multiple square grooves on the outer circle of the frame; the upper and lower parts of the frame are provided with mud flow channel conversion heads for introducing the wires in the wiring holes on the frame wall into the MWD system located in the middle of the water eye, and a pressure-bearing connector is installed at the interface of the mud flow channel conversion head, which is connected to the upper mud flow channel conversion head. It is a seven-core slip ring connector, which is connected to the telescopic short section of the MWD system, and is connected to the lower mud flow channel conversion head with a ten-core aviation plug, which is connected to the lower azimuth gamma short section, the upper mud flow channel conversion head is fixed to the upper part of the skeleton through the upper adapter drill collar, and the lower mud flow channel conversion head is fixed to the lower part of the skeleton through the lower adapter drill collar; in addition, it also includes a pressure sensor installed at the lower part, and a hole retaining ring is installed in the corresponding mounting hole of the pressure sensor to prevent loosening; The upper mud flow channel conversion head comprises an outwardly convex conversion nipple, a conversion drill collar is sleeved on the conversion nipple, the conversion nipple and the conversion drill collar are connected via an adjustment ring, the tail of the conversion nipple is connected to the mud flow channel conversion head, the tail of the mud flow channel conversion head is connected to the skeleton, wherein the conversion nipple and the mud flow channel conversion head are connected via a screw sleeve, and a large nut is used to fix the screw sleeve on the mud flow channel conversion head; The main parts of the mud channel conversion head are made of nickel-based alloy 925. The bridge joint is used for the wiring connection between the main part and the skeleton drill collar. The adjustment ring is used for error compensation between the main part and the instrument skeleton drill collar. A key is set on the main part. In addition, three sealing surfaces are set on the main part. All sealing links are reinforced with PEEK retaining rings. There is an inclined special-shaped hole in the mud flow channel conversion head, one end of which is connected to the slip ring, and the other end is connected to the ultra-deep hole in the drilling arm through a bridge plug. In addition, a large sealing ring is used to seal the two ends of the special-shaped hole; in the non-working state, a thread protector, a thread protector, a rubber protective cap and a protective cap are installed; the conversion short section includes a seven-core slip ring connector assembly, which is fixed to the inner hole at the end of the main body by a key and a wire retaining ring, and the wire at the tail of the seven-core slip ring connector assembly is connected to the pressure-bearing connector. Before the lead wire of the seven-core slip ring connector assembly is welded to the pressure-bearing connector, a polytetrafluoroethylene thin tube is first put on. After welding, the polytetrafluoroethylene thin tube is put on the tail of the pressure-bearing connector and then room-temperature curing epoxy resin is poured into it. After the epoxy resin is cured, the polytetrafluoroethylene thin tube is cut and then removed; the pressure-bearing connector is fixed to the main body by special-shaped parts and screws, and the upper and lower parts of the main body are sealing surfaces. All sealing links must be strengthened by PEEK retaining rings.

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