CN107816344B - While-drilling lateral electrode system main-screen integrated electrode structure and preparation method thereof - Google Patents
While-drilling lateral electrode system main-screen integrated electrode structure and preparation method thereof Download PDFInfo
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- CN107816344B CN107816344B CN201710855412.7A CN201710855412A CN107816344B CN 107816344 B CN107816344 B CN 107816344B CN 201710855412 A CN201710855412 A CN 201710855412A CN 107816344 B CN107816344 B CN 107816344B
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/16—Drill collars
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
Abstract
The invention discloses a main-screen integrated electrode structure of a lateral electrode system while drilling and a preparation method thereof. The invention can overcome the high requirements of the traditional lateral resistivity logging instrument on the insulating property of an electrode system and the manufacturing process, improve the measurement performance of the depth lateral resistivity and meet the requirement of long-time stable and reliable work in an oil-gas drilling environment.
Description
Technical Field
The invention belongs to the field of logging of oil and gas fields, and particularly relates to a main-screen integrated electrode structure of a lateral electrode system while drilling and a preparation method thereof.
Background
Lateral resistivity logging while drilling is the earliest method for logging while drilling to be realized and applied, and a circuit directly supplies current to a drill collar and an electrode for focusing. The current type of the electrode while drilling (not powered by induction current of a coil) has strong focusing capability and large resistivity measurement range, but is limited by the technology and the process level, so far, the electrode current type of the electrode while drilling cannot be mature and widely applied commercially, and the main reasons are that: the insulation between the electrodes of the instrument, the insulation between the electrodes and the drill collar and the wear resistance of the insulating belts of the electrode systems can not meet the requirements of long-time, high-temperature and high-pressure drilling environment while drilling.
The insulation between the electrode of the logging-while-drilling lateral resistivity logging instrument and the drill collar body is difficult to ensure by adopting an oil-filling method like a cable lateral resistivity instrument. The lateral resistivity logging instrument while drilling needs an electrode system to work underground for a long time, and the insulating property of the lateral resistivity logging instrument is easily reduced; the electrode ring is easy to damage and the electrical connection characteristic is unstable due to abrasion caused by long-time erosion of slurry. In order to solve the problems, the winding of glass fiber reinforced plastics, the filling of specific material rubber, the spraying of ceramic and the like between the drill collar and the electrode and between the drill collar and the main screen electrode have been tried for a plurality of times, and the insulation requirements cannot be met. The insulating property of the materials is deteriorated in the long-time downhole process at high temperature and high pressure, the phenomena that the insulating value is reduced to be very small after the materials are downhole, the insulating layer is seriously scoured and the like often occur, and the high requirement of the traditional lateral resistivity logging instrument on the insulating property cannot be met. Investigation and test show that: the insulating performance required by lateral logging is difficult to achieve by adopting the traditional double-lateral electrode system structure on the drill collar while drilling, and the performance of the electrode system manufactured on the drill collar cannot be ensured at present. Therefore, a novel main-screen integrated electrode structure and a manufacturing method are urgently needed, the high requirements of the traditional lateral instrument on the insulating property and the manufacturing process of an electrode system are overcome by utilizing the soft shielding property, the poor logging effect caused by the reduction of the high-temperature and high-voltage insulating property is avoided, and the stability and the reliability of the logging-while-drilling lateral resistivity logging instrument are improved.
Disclosure of Invention
The invention aims to provide a main-screen integrated electrode structure of a lateral electrode system while drilling and a preparation method thereof, which are used for solving the problems in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
a lateral electrode system while drilling and a screen integrated electrode structure comprise a drill collar body, wherein a first insulating layer is sleeved on the outer side of the drill collar body, a shielding electrode is sleeved on the outer side of the first insulating layer, an annular mounting groove is formed in the shielding electrode, a main electrode is arranged in the annular mounting groove, a second insulating layer is arranged between the main electrode and the shielding electrode, and a threading hole for a lead bundle of the main electrode to pass through is formed in the shielding electrode.
Furthermore, the shielding electrode is divided into a first shielding electrode and a second shielding electrode by the annular mounting groove, and the first shielding electrode and the second shielding electrode are connected through a metal body at the bottom of the annular mounting groove.
Further, the second insulating layer includes an insulating layer located inside the main electrode and insulating layers located at both sides of the main electrode, and outer diameters of the insulating layers located at both sides of the main electrode are the same as outer diameters of the main electrode, the first shielding electrode, and the second shielding electrode.
Further, the second insulating layer is a glass fiber reinforced plastic insulating layer or a rubber insulating layer.
Furthermore, a plurality of electrode rings are respectively arranged on two sides of the shielding electrode, and the number of the electrode rings on the two sides of the shielding electrode is equal.
Furthermore, insulating layers are arranged between the shielding electrode and the adjacent electrode rings and between the adjacent electrode rings.
The preparation method of the main-screen integrated electrode structure of the lateral electrode system while drilling comprises the following steps:
the method comprises the following steps: preparing a first insulating layer in the circumferential direction of the drill collar body, and then installing a shielding electrode on the outer side of the first insulating layer;
step two: processing an annular mounting groove in the middle of the shielding electrode;
step three: polishing the surface of the annular mounting groove;
step four: preparing an insulating layer on the bottom surface of the annular mounting groove, mounting a main electrode on the insulating layer, and enabling a lead bundle of the main electrode to penetrate out of a threading hole in the shielding electrode;
step five: and preparing an insulating layer between the main electrode and two side surfaces of the annular mounting groove, wherein the insulating layer and the insulating layer prepared in the fourth step form a second insulating layer together.
Further, the shielding electrode is divided into a first shielding electrode and a second shielding electrode by the annular mounting groove, and the first shielding electrode and the second shielding electrode are connected through a metal body at the bottom of the annular mounting groove.
Further, the outer diameters of the insulating layers between the main electrode and the two side surfaces of the annular mounting groove are consistent with the outer diameters of the main electrode, the first shielding electrode and the second shielding electrode.
Further, the second insulating layer is a glass fiber reinforced plastic insulating layer or a rubber insulating layer.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention develops a prototype and carries out multi-well logging tests in an oil field by adopting the main-screen integrated electrode structure of the lateral electrode system while drilling, and obtains qualified deep and shallow lateral resistivity curves, thereby verifying the effect of the integrated electrode structure. The invention can be applied to other logging-while-drilling lateral resistivity logging instruments or cable lateral resistivity logging instruments.
The main-screen integrated electrode structure of the lateral electrode system while drilling prepared by the method can seal the current of the main electrode and avoid the direct leakage into the drill collar body due to poor effect of the bottom insulating layer. In addition, according to the working principle of the lateral resistivity logging instrument, the control circuit can ensure that the potentials of the main electrode, the first shielding electrode or the second shielding electrode are equal, and the leakage current flowing to the loop electrode through the outer sheath of the lead or the wire groove due to poor insulation of the main electrode can be blocked by utilizing the equipotential characteristics of the main electrode, the first shielding electrode and the second shielding electrode, so that the measuring effect of improving the deep and shallow lateral resistivity is achieved, and the higher requirement of the lateral instrument on the insulating property between the electrodes is reduced.
Drawings
FIG. 1 is a schematic diagram of a conventional lateral resistivity logging tool primary shield electrode system;
FIG. 2 is a schematic diagram of a lateral resistivity logging instrument primary-shield integrated electrode structure of the present invention;
FIG. 3 shows a lateral electrode system integrated electrode A of the present invention1A0A1' schematic structural diagram;
FIG. 4 is a schematic diagram of an electrode system for a dual lateral resistivity logging tool according to the present invention;
FIG. 5 is a schematic diagram of the structure of the present invention for a three-sided electrode system;
FIG. 6 is a schematic diagram of the structure of the lateral electrode system for array according to the present invention;
FIG. 7 is a schematic structural diagram of the present invention for an azimuthal lateral electrode system.
Wherein, 1, a drill collar body; 2. a first insulating layer; 3. a second insulating layer; 4. a first lead beam; 5. a second lead beam; 6. a third lead beam; a. the0A main electrode; a. the1A first shield electrode; a. the1', a second shielding electrode; a. the2、A2′、A3、A3′、……AN、AN' are electrode rings; B. b' are all loop electrodes.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
conventional lateral resistivity logging instrumentThe electrode system main-shield electrode structure is shown in FIG. 1, which has the disadvantage of main electrode A0The insulating property between the main electrode A and the drill collar can not meet the requirement of long-time, high-temperature and high-pressure drilling environment, and the main electrode A is lowered along with the performance reduction of the insulating layer after the instrument is put into the well0The current may leak to the drill collar body 1 through the glass fiber reinforced plastic material or shunt a part along the wiring groove, which will reduce the focusing effect of the main current of the lateral resistivity logging, resulting in a lower resistivity measurement value. Although oil can be filled between the cable lateral resistivity logging electrode and the metal mandrel to ensure the insulating property of the cable lateral resistivity logging electrode, the oil can not be filled between the cable lateral resistivity logging electrode and the metal mandrel in the logging-while-drilling environment.
In order to overcome the problems and the defects in the process of logging the lateral resistivity while drilling, the invention provides the electrode system main-screen integrated electrode structure of the logging-while-drilling lateral resistivity logging instrument, which is particularly suitable for the logging-while-drilling lateral resistivity logging instrument, so as to improve the measurement effect of the deep lateral resistivity and the shallow lateral resistivity and reduce the requirement of the logging-while-drilling lateral resistivity logging instrument on the insulating property of the electrode system. As shown in fig. 2, the present invention uses a shielding electrode to surround the main electrode a0The electrode structure of (1), i.e. a main electrode A can be processed in the middle of the shielding electrode0And the upper and lower ends of the shielding electrode are respectively used as a first shielding electrode A1And a second shielding electrode A1', the annular mounting groove bottom metal body is used for shielding the first shielding electrode A1And a second shielding electrode A1' are connected into a whole; a main electrode A is arranged in the middle after a glass fiber reinforced plastic or rubber insulating layer is wound on the bottom of the annular mounting groove0And then main electrode A0The lead (i.e., the first lead bundle 4) is led from the second shielding electrode A1The first lead wire bundle 4 passes through the inner threading hole, and the threading hole is properly designed to ensure that the first lead wire bundle 4 can pass through smoothly and the sheath of the first lead wire bundle 4 can pass through the second shielding electrode A1' on intimate contact; finally, the main electrode A is processed0The insulating layers on both sides are wound and the outer diameter is wound to the main electrode A0And a first shielding electrode A1The outer diameters are consistent.
This structure can enclose the main electrode A0The current can be prevented from directly leaking into the drill collar body 1 due to the poor effect of the bottom insulating layer. In addition, according to the working principle of the lateral resistivity logging instrument, the control circuit can ensure the main electrode A0A first shielding electrode A1Or the second shielding electrode A1' equal potential, using main electrode A0A first shielding electrode A1A second shielding electrode A1' equipotential characteristic can block the main electrode A0The insulation is not good, and the leakage current flowing to the loop electrode through the sheath or the wire groove of the lead achieves the measurement effect of improving the lateral resistivity of the deep and shallow parts and reduces the higher requirement of the lateral instrument on the insulation performance between the electrodes.
The preparation process of the present invention is described in detail below:
machining of the main electrode A on the integral shield electrode0The annular mounting groove is filled with high-temperature wear-resistant insulating materials such as glass fiber reinforced plastics or rubber, and certain insulativity between the main screen electrodes of the electrode system is ensured; the main electrode A is made by processing threading holes in the shielding electrode0The first lead wire bundle 4 is led out from the threading hole, and by utilizing the principle that the potentials of a main electrode and a shielding electrode of the first lead wire bundle are equal and the design idea of soft shielding, the main current can better achieve the focusing effect through the equipotential of the main shielding electrode, the requirement of the instrument on higher insulativity between the electrodes is reduced, and the stability and the reliability of the lateral resistivity instrument during drilling in the high-temperature and high-pressure environment for long-time working are improved.
The structure of the invention adopts a first shielding electrode A1And a second shielding electrode A1' surrounding main electrode A0Monitoring electrode A0Is arranged on the corresponding main electrode A0In the surface layer region, the first shield electrode A1And a second shielding electrode A1The bottom metal bodies are connected into a whole through an annular mounting groove, and a threading hole is punched in the shielding electrode to lead the main electrode A to be0Monitor electrode A0 *The lead is led out from the threading hole of the shielding electrode, the main electrode A0And the shielding electrode is filled with high-temperature wear-resistant insulating materials such as glass fiber reinforced plastics or rubber, and the like, wherein the insulating material of the glass fiber reinforced plastics is high-temperature and high-pressure resistant epoxy resinThe material of the rubber insulating layer is fluororubber, the threading in the processing hole can be used for electrical connection or other purposes, and the filling by adopting the glass fiber reinforced plastics as the insulating layer is to firstly vacuumize the cavity and then inject resin into the cavity by an injection machine by using the VARTM technology to wind the glass fiber reinforced plastics insulating layer on the polytetrafluoroethylene coating; the filling with the rubber insulating layer is realized by uniformly pressing and molding the rubber layer through a special mold, and attaching the rubber layer to the shielding electrode and the main electrode A0In the gap, main electrode A0And the rest electrode rings are made of TC11 nonmagnetic stainless steel, and are fastened outside the second insulating layer 3 in a fixing mode that the upper electrode ring and the lower electrode ring are fastened together and are fixed through pins and then are electrically welded. The main-screen integrated electrode structure and the process method can be used for various lateral resistivity logging instruments including a drilling and cable lateral resistivity logging instrument. The invention can be used for a logging-while-drilling/cable dual lateral resistivity logging instrument, as shown in figure 4; it can also be used for the logging while drilling/wireline three-side resistivity logging instrument, see fig. 5; or for a LWD/CABLE ARRAY SIDE RESISTANCE logger, see FIG. 6 (electrode Ring A)3、A3′、……AN、AN' third to nth shield electrode pairs, respectively, lateral to the array); or for a drill-while-drilling/wireline azimuth lateral resistivity tool see figure 7.
The preparation process of the invention is as follows:
1) surrounding main electrode A with a shield electrode0The electrode structure of (1) can process a main electrode A in the middle of the drill collar pup joint (i.e. shielding electrode)0The upper and lower ends of the shielding electrode are respectively used as a first shielding electrode A1And a second shielding electrode A1' the two ends of the metal body at the bottom of the annular mounting groove are connected into a whole.
2) And treating and polishing the inner surface of the annular mounting groove so as to facilitate winding a glass fiber reinforced plastic insulating layer or pouring a rubber insulating layer on the annular mounting groove.
3) After the bottom of the annular mounting groove is wound with a glass fiber reinforced plastic or poured with a rubber insulating layer, a main electrode A with a certain width is mounted in the middle0And then main electrode A0The lead wire is led from the second shielding electrode A1' an inner threading hole is arranged in the inner threading hole, the threading hole is designed to be proper,it is ensured that the first lead beam 4 can smoothly pass through, and it is also ensured that the sheath of the first lead beam 4 can be in close contact with the shielding electrode.
4) Finally, the main electrode A is processed0The insulating layers on both sides are wound or cast, and the outer diameter is wound or cast to the main electrode A0A first shielding electrode A1And a second shielding electrode A1' outside diameter is uniform.
The integrated electrode structure of the main screen and the screen of the lateral electrode system while drilling can be applied to the design of the electrode system of the dual lateral resistivity logging instrument while drilling, and the structural schematic diagram is shown in figure 4. Wherein the second lead wire 5 is the power supply signal lead of the first shielding electrode during the manufacture of the dual lateral electrode system while drilling, and the third lead wire 6 is the electrode A during the manufacture of the lateral electrode system2、A2'the short-circuit connection between, B, B' is the return electrode of the lateral instrument.
Claims (7)
1. The integrated electrode structure of the lateral electrode system while drilling and the screen is characterized by comprising a drill collar body (1), wherein a first insulating layer (2) is sleeved outside the drill collar body (1), a shielding electrode is sleeved outside the first insulating layer (2), an annular mounting groove is formed in the shielding electrode, and a main electrode (A) is arranged in the annular mounting groove0) And a main electrode (A)0) A second insulating layer (3) is arranged between the shielding electrode and the first electrode, and a main electrode (A) is arranged on the shielding electrode0) The lead wire bundle (4) passes through the threading hole, and the shielding electrode is divided into a first shielding electrode (A) by an annular mounting groove1) And a second shielding electrode (A)1') and a first shielding electrode (A)1) And a second shielding electrode (A)1') are connected through a metal body at the bottom of the annular mounting groove, a plurality of electrode rings are respectively arranged at two sides of the shielding electrode, and the number of the electrode rings at two sides of the shielding electrode is equal.
2. The integrated electrode structure while drilling of claim 1, wherein the second insulating layer (3) comprises a main electrode (A)0) An inner insulating layer and a main electrode (A)0) Insulating layers on both sidesOn the main electrode (A)0) Outer diameter of insulating layer and main electrode (A) on both sides0) A first shielding electrode (A)1) And a second shielding electrode (A)1') have a uniform outer diameter.
3. The integrated electrode structure while drilling of the lateral electrode system main-screen as claimed in claim 1, wherein the second insulating layer (3) is a glass fiber reinforced plastic insulating layer or a rubber insulating layer.
4. The structure of the electrode while drilling as recited in claim 1, wherein an insulating layer is disposed between the shielding electrode and its adjacent electrode rings and between the adjacent electrode rings.
5. The preparation method of the integrated electrode structure while drilling of the lateral electrode system main-screen is characterized by comprising the following steps:
the method comprises the following steps: preparing a first insulating layer (2) in the circumferential direction of the drill collar body (1), and then installing a shielding electrode on the outer side of the first insulating layer (2);
step two: processing an annular mounting groove in the middle of the shielding electrode;
step three: polishing the surface of the annular mounting groove;
step four: preparing an insulating layer on the bottom surface of the annular mounting groove, and mounting a main electrode (A) on the insulating layer0) And a main electrode (A)0) The lead wire bundle (4) penetrates out of the threading hole in the shielding electrode;
step five: on the main electrode (A)0) And preparing an insulating layer between the two side surfaces of the annular mounting groove, wherein the insulating layer and the insulating layer prepared in the step four form a second insulating layer (3).
6. The method for preparing the integrated electrode structure while drilling of the lateral electrode system main-screen as claimed in claim 5, wherein the main electrode (A) is0) An outer diameter of the insulating layer and a main electrode (A) between the two side surfaces of the annular mounting groove0) First shieldElectrode (A)1) And a second shielding electrode (A)1') have a uniform outer diameter.
7. The preparation method of the integrated electrode structure while drilling of the lateral electrode system main-screen as claimed in claim 5, wherein the second insulating layer (3) is a glass fiber reinforced plastic insulating layer or a rubber insulating layer.
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| CN201710855412.7A CN107816344B (en) | 2017-09-20 | 2017-09-20 | While-drilling lateral electrode system main-screen integrated electrode structure and preparation method thereof |
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| JPH03199672A (en) * | 1989-12-27 | 1991-08-30 | Hitachi Chem Co Ltd | Insulating cap for power distribution device and its manufacture |
| CN103032062B (en) * | 2012-12-31 | 2016-01-27 | 中国海洋石油总公司 | A kind of digital lateral electrodes |
| CN103643948B (en) * | 2013-12-16 | 2017-05-31 | 西南石油大学 | A kind of Dual-electrical azimuthal imaging logging instrument and method |
| CN103643937B (en) * | 2013-12-16 | 2016-08-17 | 西南石油大学 | Measure formation rock dielectric constant and resistivity Dual Laterolog Logging Method and instrument |
| CN105525918B (en) * | 2014-10-24 | 2021-09-03 | 中国石油集团长城钻探工程有限公司 | Dual lateral logging instrument, electrode system thereof and formation resistivity measuring method |
| CN104453883A (en) * | 2014-12-10 | 2015-03-25 | 中国石油天然气集团公司 | Electrode system structure for lateral resistivity logging while drilling instrument and method for manufacturing electrode system structure |
| CN105587315B (en) * | 2015-12-18 | 2019-01-15 | 杭州瑞利声电技术有限公司 | A kind of main electrode probe lateral based on soft-focus array |
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