US20030173084A1 - Downhole fishing tool for retrieving metallic debris from a borehole - Google Patents
Downhole fishing tool for retrieving metallic debris from a borehole Download PDFInfo
- Publication number
- US20030173084A1 US20030173084A1 US10/096,268 US9626802A US2003173084A1 US 20030173084 A1 US20030173084 A1 US 20030173084A1 US 9626802 A US9626802 A US 9626802A US 2003173084 A1 US2003173084 A1 US 2003173084A1
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- US
- United States
- Prior art keywords
- fishing tool
- downhole
- radial distance
- radioactive marker
- longitudinal axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000002285 radioactive effect Effects 0.000 claims abstract description 76
- 239000003550 marker Substances 0.000 claims abstract description 73
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 47
- 238000000034 method Methods 0.000 claims description 8
- 230000007704 transition Effects 0.000 claims description 7
- 230000008878 coupling Effects 0.000 claims description 5
- 238000010168 coupling process Methods 0.000 claims description 5
- 238000005859 coupling reaction Methods 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 4
- 238000010304 firing Methods 0.000 claims description 2
- 238000005755 formation reaction Methods 0.000 description 37
- 238000005056 compaction Methods 0.000 description 6
- 238000007667 floating Methods 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000941 radioactive substance Substances 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- 206010073306 Exposure to radiation Diseases 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- TVFDJXOCXUVLDH-RNFDNDRNSA-N cesium-137 Chemical compound [137Cs] TVFDJXOCXUVLDH-RNFDNDRNSA-N 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 229910000938 samarium–cobalt magnet Inorganic materials 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B31/00—Fishing for or freeing objects in boreholes or wells
- E21B31/06—Fishing for or freeing objects in boreholes or wells using magnetic means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V11/00—Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00
- G01V11/002—Details, e.g. power supply systems for logging instruments, transmitting or recording data, specially adapted for well logging, also if the prospecting method is irrelevant
Definitions
- the present invention relates generally to systems which monitor the subsidence and compaction of subterranean formations by measuring the shifting of spaced-apart radioactive marker bullets implanted in the formation.
- the invention concerns a method and apparatus for retrieving stray radioactive marker bullets loosely positioned in a subterranean borehole.
- One method of monitoring formation subsidence and compaction involves implanting radioactive bullets within the subterranean formation as depth markers. The positions of the implanted bullets can then be monitored over the years using a downhole logging tool which detects the gamma rays emitted by the radioactive bullets.
- Radioactive marker bullets into a subterranean formation
- bullets fired from the radioactive marker bullet gun may bounce off the subterranean formation and can be lost in the borehole.
- Some of these “stray” radioactive marker bullets in the borehole may be partially lodged in the wall of the borehole or may be resting on ledges of the borehole wall. Other of the stray radioactive marker bullets may simply fall to the bottom of the borehole.
- These stray radioactive marker bullets are typically left in the borehole and cemented. When the next section of the borehole is drilled, some of the stray radioactive marker bullets may be crushed, thereby exposing the drilling mud to radioactive particles, and risking human exposure to radiation.
- a further object of the invention is to provide a downhole tool assembly for implanting radioactive marker bullets into a subterranean formation and retrieving any stray radioactive marker bullets from the borehole.
- a still further object of the invention is to provide a wellbore comprising a borehole, a stray radioactive marker bullet located in the borehole, and a downhole fishing tool for retrieving the stray radioactive marker bullet from the borehole.
- Another object of the invention is to provide a method of retrieving stray radioactive marker bullets that does not require a fishing tool to be separately run down the borehole after the radioactive marker bullets are implanted into the subterranean formation.
- a downhole fishing tool comprising a main body and a side magnet.
- the main body extends along a longitudinal axis and presents a pair of axially spaced wide outer surfaces.
- the side magnet is coupled to the body and axially positioned between the wide outer surfaces.
- the side magnet presents a generally radially facing side surface.
- the wide outer surfaces are radially spaced from the longitudinal axis by a first maximum radial distance, while the side surface is radially spaced from the longitudinal axis by a second maximum radial distance.
- the first maximum radial distance is at least 10 percent greater than the second maximum radial distance.
- a downhole fishing tool for retrieving radioactive marker bullets from a borehole extending into a subterranean formation.
- the downhole fishing tool comprises a main body, a first group of magnets, a second group of magnets, and a third group of magnets.
- the main body extends along a longitudinal axis and includes axially spaced proximal and distal ends.
- the body presents a first wide outer surface proximate the distal end, a third wide outer surface proximate the proximal end, and a second wide outer surface axially spaced from and positioned between the first and second wide outer surfaces.
- the first group of magnets is coupled to the body, circumferentially spaced from one another, and axially positioned between the first and second wide outer surfaces.
- the second group of magnets is coupled to the body, circumferentially spaced from one another, and axially positioned between the second and third wide outer surfaces.
- the magnets in the third group of magnets are coupled to the distal end of the body and are spaced-apart from one another.
- an elongated downhole tool for inserting radioactive marker bullets into a subterranean formation and retrieving stray radioactive marker bullets not properly penetrating into the formation.
- the downhole tool comprises a radioactive marker bullet gun having a normally upper end and a normally lower end and a magnetic fishing tool having a proximal end coupled to the normally lower end of the radioactive marker bullet gun.
- the fishing tool includes a side magnet axially positioned between the proximal and distal ends of the body, and an end magnet positioned proximate the distal end of the tool.
- the side magnet presents an exposed side surface facing in a first direction and the end magnet presents an exposed bottom surface facing in a second direction.
- the first direction is within 30 degrees of perpendicular to the direction of extension of the longitudinal axis of the downhole tool.
- the second direction is within 30 degrees of parallel to the direction of extension of the longitudinal axis.
- a wellbore system in a subterranean formation comprising a borehole, a stray radioactive marker bullet, and a fishing tool.
- the borehole extends downwardly into the subterranean formation.
- the stray radioactive marker bullet is loosely positioned in the borehole.
- the fishing tool is positioned in the borehole and includes a plurality of magnets operable to attract and hold the stray radioactive marker bullet so that the stray radioactive marker bullet can be retrieved from the borehole along with the fishing tool.
- a process comprising the steps of: (a) lowering a fishing tool into a borehole in a subterranean formation; (b) traversing the borehole with the fishing tool, thereby causing the fishing tool to be positioned proximate a stray radioactive marker bullet located in the borehole; (c) coupling the stray radioactive marker bullet to the fishing tool by magnetic attraction; and (d) retrieving the fishing tool and the radioactive marker bullet coupled thereto from the borehole.
- FIG. 1 is an elevation view of a wellbore system in a subterranean formation, particularly illustrating a downhole tool for implanting radioactive marker bullets and retrieving stray radioactive marker bullets lost in the borehole;
- FIG. 2 is a side view of a downhole magnetic fishing tool constructed in accordance of the present invention, particularly illustrating the shape of the main body of the fishing tool as well as the position of the magnets on the body;
- FIG. 3 is an end view of the downhole magnetic fishing tool illustrated in FIG. 2, particularly illustrating the end magnets attached to the distal end of the tool;
- FIG. 4 is an isometric view of the downhole magnetic fishing tool illustrated in FIGS. 2 and 3.
- a wellbore system 10 is illustrated as generally comprising a borehole 12 extending downward into a subterranean formation 14 , implanted radioactive marker bullets (RMBs) 16 , stray side RMBs 18 , stray bottom RMBs 20 , stray floating RMB 21 , and a downhole tool assembly 22 .
- Downhole tool assembly 22 is received in borehole 12 and is supported by a cable 24 which extends into borehole 12 and is coupled to surface equipment 26 . Cable 24 and surface equipment 26 cooperate to raise and lower tool assembly 22 in borehole 12 .
- cable 24 is a wireline which not only physically supports tool assembly 22 , but also includes electrical conductors for carrying power and/or electrical control signals from surface equipment 26 to tool assembly 22 .
- Downhole tool assembly 22 comprises a radioactive marker bullet gun 28 and a magnetic fishing tool 30 .
- Gun 28 is operable to propel radioactive marker bullets (RMBs) outward and into subterranean formation 14 .
- RMBs radioactive marker bullets
- Properly implanted RMBs 16 are snugly received in subterranean formation 14 so that any local shifting of subterranean formation 14 causes corresponding shifting of implanted RMBs 16 in that location.
- gun 28 is designed to fire radioactive marker bullets into subterranean formation 14 , several factors, such as improper operation of gun 28 and/or extremely high density of subterranean formation 14 , may cause inadequate lodging of the radioactive marker bullets in subterranean formation 14 .
- Such stray RMBs 18 , 20 , 21 may partially lodge in formation 14 (e.g., stray side RMB 18 b ), may fall (e.g., stray floating RMB 21 ) in borehole 12 and come to rest on a ledge of the sidewall of borehole 12 (e.g., stray side RMB 18 a ), or may simply fall to the bottom of borehole 12 (e.g., stray bottom RMBs 20 ).
- Magnetic fishing tool 30 is operable to attract and hold stray RMBs 18 , 20 which are relatively loosely positioned in borehole 12 .
- Magnetic fishing tool 30 comprises a first group of side magnets 32 , a second group of side magnets 34 axially spaced from the first group of side magnets 32 , and a group of end magnets 36 .
- Side magnets 32 , 34 face generally outward toward the side walls of borehole 12 so that stray RMBs 18 , 21 can be pulled into contact with and held against the outwardly facing surface of side magnets 32 , 34 by magnetic force.
- End magnets 36 face generally downward toward the bottom of borehole 12 so that stray bottom RMBs 20 can be pulled into contact with and held against the downwardly facing surface of end magnets 36 by magnetic force.
- RMBs 16 , 18 , 20 , 21 can be any conventional bullet capable of being coupled to magnets 32 , 24 , 36 of fishing tool 30 by magnetic force.
- RMBs 16 , 18 , 20 , 21 include a quantity of a radioactive substance, for example, a pellet of Cesium 137 of about 100-150 micro-curies.
- the radioactive substance is preferably encased in a durable, metallic casing (shaped as a conventional bullet) which can be attracted to and held in contact with magnets 32 , 24 , 36 of fishing tool 30 .
- Radioactive marker bullet gun 28 can be any conventional radioactive marker bullet gun capable of propelling radioactive marker bullets into subterranean formation 14 .
- radioactive marker bullet gun An example of a suitable radioactive marker bullet gun is the “E-Gun (Bullet) Perforating System” available from Baker Atlas, Houston, Tex. Another radioactive marker bullet gun which can be modified for use with fishing tool 30 is described in U.S. Pat. No. 4,916,312 (assigned to Schlumberger Technology), the entire disclosure of which is incorporated herein by reference. Other suitable radioactive marker bullet gun configurations are well known in the art.
- magnetic fishing tool 30 generally comprises an elongated main body 38 extending along a longitudinal axis 39 and three groups of magnets 32 , 34 , 36 coupled to body 38 at specific axial locations.
- Body 38 includes a proximal end 40 adapted to be coupled to a radioactive marker bullet gun and a distal end 42 which normally faces downward when fishing tool 30 is inserted into a borehole.
- Proximal end 40 preferably includes a male threaded member 44 for coupling fishing tool 30 to a normally lower end of a radioactive marker bullet gun.
- the outer surface of main body 38 includes first, second, and third axially spaced wide outer surfaces 46 , 48 , 50 , first and second axially spaced narrow outer surfaces 52 , 54 , a plurality of tapered axially spaced transition surfaces 56 , a terminal end surface 58 , and a terminal tapered surface 60 .
- First wide outer surface 46 is located proximate distal end 42 .
- Third wide outer surface 50 is located proximate proximal end 40 .
- Second wide outer surface 48 is axially spaced from and positioned between first and third wide outer surfaces 46 , 50 .
- First narrow outer surface 52 is axially positioned between first and second wide outer surfaces 46 , 48 .
- Second narrow outer surface 54 is axially positioned between second and third wide outer surfaces 48 , 50 .
- Each transition surface 56 provides a tapered transition between one of narrow outer surfaces 52 , 54 and an adjacent one of wide outer surfaces 46 , 48 , 50 .
- Terminal tapered surface 60 provides a tapered transition between first wide outer surface 46 and terminal end surface 58 .
- wide outer surfaces 46 , 48 , 50 and narrow outer surfaces 52 , 54 are substantially cylindrical in shape
- transition surfaces 56 and terminal tapered surface 60 are substantially frustoconical in shape
- terminal end surface 58 is substantially flat.
- First and second groups of side magnets 32 , 34 each comprise a plurality of individual magnets which are circumferentially spaced around a respective narrow outer surface 52 , 54 of main body 38 .
- each of first and second groups of side magnets 32 , 34 comprises from 3 to 12 individual magnets, more preferably from 4 to 8 individual magnets.
- the individual magnets in each of first and second groups of side magnets 32 , 34 are preferably substantially symmetrically spaced around longitudinal axis 39 .
- Each magnet in first and second groups of side magnets 32 , 34 presents a substantially flat outwardly-facing side surface 62 .
- Side surfaces 62 preferably face generally radially away from longitudinal axis 39 of main body 38 .
- each side surface 62 of each individual magnet in the groups of side magnets 32 , 34 faces in a direction which is within 30 degrees of perpendicular to the direction of extension of longitudinal axis 39 , more preferably within 15 degrees of perpendicular to the direction of extension of longitudinal axis 39 , and most preferably substantially perpendicular to the direction of extension of longitudinal axis 39 .
- Wide outer surfaces 46 , 48 , 50 are preferably substantially cylindrical and have substantially the same width. Wide outer surfaces 46 , 48 , 50 are radially spaced from longitudinal axis 39 by a maximum radial distance which is greater than the maximum distance between longitudinal axis 39 and side surfaces 62 of side magnets 32 , 34 . It is important for wide outer surfaces 46 , 48 , 50 to extend a greater radial distance from longitudinal axis 39 than side surfaces 62 of side magnets 32 , 34 in order to protect a captured side RMB 64 from being disengaged from (i.e., “scraped off”) side surface 62 by the sidewall of the borehole when fishing tool 30 is shifted up and down in the borehole.
- a captured side RMB 64 from being disengaged from (i.e., “scraped off”) side surface 62 by the sidewall of the borehole when fishing tool 30 is shifted up and down in the borehole.
- the maximum radial distance between longitudinal axis 39 and wide outer surfaces 46 , 48 , 50 is at least 10 percent greater than the maximum radial distance between longitudinal axis 39 and side surfaces 62 of side magnets 32 , 34 , more preferably at least 20 percent greater, and most preferably at least 40 percent greater.
- maximum radial distance means the maximum distance from a central axis (e.g., longitudinal axis 39 ) to any point on a particular surface or group of surfaces, measured perpendicular to the direction of extension of the central axis.
- Narrow outer surfaces 52 , 54 are preferably substantially cylindrical and have substantially the same width.
- the maximum radial distance between longitudinal axis 39 and narrow outer surfaces 52 , 54 is less than the maximum radial distance between longitudinal axis 39 and wide outer surfaces 46 , 48 , 50 .
- the maximum radial distance between longitudinal axis 39 and narrow outer surfaces 52 , 54 can be less than the maximum radial distance between longitudinal axis 39 and side surfaces 62 of side magnets 32 , 34 (i.e., when side surfaces 62 of side magnets 32 , 34 are slightly raised from narrow outer surfaces 52 , 54 ).
- the maximum radial distance between longitudinal axis 39 and narrow outer surfaces 52 , 54 and the maximum radial distance between longitudinal axis 39 and side surfaces 62 of side magnets 32 , 34 is substantially the same (i.e., when side surfaces 62 of side magnets 32 , 34 are substantially flush with narrow outer surfaces 52 , 54 ).
- Group of end magnets 36 comprises a plurality of spaced-apart individual magnets.
- group of end magnets 36 comprises from 1 to 8 individual magnets, more preferably from 2 to 6 individual magnets, and most preferably 3 individual magnets.
- Each end magnet 36 presents a substantially flat downwardly-facing bottom surface 66 .
- Bottom surfaces 66 preferably face generally axially away from main body 38 in a direction which is within 30 degrees of parallel to the direction of extension of longitudinal axis 39 , more preferably within 15 degrees of parallel to the direction of extension of longitudinal axis 39 , and most preferably substantially parallel to the direction of extension of longitudinal axis 39 .
- the direction in which bottom surfaces 66 of end magnets 36 face and the direction in which each side surface 62 of side magnets 32 , 34 face are preferably within 30 degrees of perpendicular to one another, more preferably within 15 degrees to perpendicular to one another, and most preferably substantially perpendicular to one another.
- Side surfaces 62 of side magnets 32 , 34 and bottom surfaces 66 of end magnets 36 are preferably exposed (i.e., uncovered) so that radioactive marker bullets located away from side and bottom surfaces 62 , 66 can be pulled directly into contact with and held against side and bottom surfaces 62 , 66 by magnetic force.
- downhole tool assembly 22 can be assembled by coupling magnetic fishing tool 30 to a normally lower end of radioactive marker bullet gun 28 .
- a normally upper end of radioactive marker bullet gun 28 can then be coupled to cable 24 .
- Downhole tool assembly 22 can then be lowered into borehole 12 .
- radioactive marker bullets RMBs
- stray RMBs e.g., stray floating RMB 21
- they may become attracted by and coupled to side magnets 32 , 34 of fishing tool 30 .
- Some of the stray RMBs e.g., stray side RMB 18 a
- Other of the stray RMBs e.g., stray bottom RMBs 20
- Stray RMBs 18 , 21 can be pulled into contact with and coupled to side magnets 32 , 34 of fishing tool 30 when fishing tool 30 is passed by and/or contacted with stray side RMBs 18 .
- Stray bottom RMBs 20 can be pulled into contact with and coupled to end magnets 36 when fishing tool 30 is lowered to the bottom of borehole 12 .
- the stray RMBs coupled to magnets 32 , 34 , 36 of magnetic fishing tool 30 are removed therewith.
- downhole tool 22 allows implanted RMBs 16 to be fired into subterranean formation 14 and stray RMBs 18 , 20 , 21 to be retrieved from borehole 12 during a single run of downhole tool assembly 22 in borehole 12 .
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Abstract
Description
- 1. Field of the Invention
- The present invention relates generally to systems which monitor the subsidence and compaction of subterranean formations by measuring the shifting of spaced-apart radioactive marker bullets implanted in the formation. In another aspect, the invention concerns a method and apparatus for retrieving stray radioactive marker bullets loosely positioned in a subterranean borehole.
- 2. Description of the Prior Art
- The production of water and hydrocarbon fluids from subterranean formations depletes reservoir pressure and removes the fluids from the interstatial pores of the subterranean formation. As fluids are removed, the reduction of pressure in the subterranean formation may cause collapsing (i.e., subsidence) and compaction of the subterranean formation. This subsidence and corresponding compaction is heightened when the subterranean formation comprises chalk or other rock having relatively high porosity and a low compressive strength. An excessive amount of subsidence may result in well casing failure or rig collapse. Further, excessive compaction can permanently damage the permeability and hydrocarbon producing capability of a subterranean formation if the interstatial pores are irreparably closed. It is therefore desirable to monitor the subterranean formation to detect the onset of subsidence and compaction.
- One method of monitoring formation subsidence and compaction involves implanting radioactive bullets within the subterranean formation as depth markers. The positions of the implanted bullets can then be monitored over the years using a downhole logging tool which detects the gamma rays emitted by the radioactive bullets.
- One common method of implanting radioactive marker bullets into a subterranean formation involves lowering a radioactive marker bullet gun into the borehole and firing radioactive marker bullets radially out from the radioactive marker bullet gun and into the formation. When the subterranean formation is formed of a high density rock, bullets fired from the radioactive marker bullet gun may bounce off the subterranean formation and can be lost in the borehole. Some of these “stray” radioactive marker bullets in the borehole may be partially lodged in the wall of the borehole or may be resting on ledges of the borehole wall. Other of the stray radioactive marker bullets may simply fall to the bottom of the borehole. These stray radioactive marker bullets are typically left in the borehole and cemented. When the next section of the borehole is drilled, some of the stray radioactive marker bullets may be crushed, thereby exposing the drilling mud to radioactive particles, and risking human exposure to radiation.
- It is, therefore, an object of the present invention to provide a downhole fishing tool for retrieving stray radioactive marker bullets from a borehole during placement of radioactive marker bullets in a subterranean formation.
- A further object of the invention is to provide a downhole tool assembly for implanting radioactive marker bullets into a subterranean formation and retrieving any stray radioactive marker bullets from the borehole.
- A still further object of the invention is to provide a wellbore comprising a borehole, a stray radioactive marker bullet located in the borehole, and a downhole fishing tool for retrieving the stray radioactive marker bullet from the borehole.
- Another object of the invention is to provide a method of retrieving stray radioactive marker bullets that does not require a fishing tool to be separately run down the borehole after the radioactive marker bullets are implanted into the subterranean formation.
- It should be noted that the above-listed objects are exemplary, and not all of the above objects need to be accomplished by the invention described and claimed herein.
- Accordingly, in one embodiment of the present invention, there is provided a downhole fishing tool comprising a main body and a side magnet. The main body extends along a longitudinal axis and presents a pair of axially spaced wide outer surfaces. The side magnet is coupled to the body and axially positioned between the wide outer surfaces. The side magnet presents a generally radially facing side surface. The wide outer surfaces are radially spaced from the longitudinal axis by a first maximum radial distance, while the side surface is radially spaced from the longitudinal axis by a second maximum radial distance. The first maximum radial distance is at least 10 percent greater than the second maximum radial distance.
- In another embodiment of the present invention, there is provided a downhole fishing tool for retrieving radioactive marker bullets from a borehole extending into a subterranean formation. The downhole fishing tool comprises a main body, a first group of magnets, a second group of magnets, and a third group of magnets. The main body extends along a longitudinal axis and includes axially spaced proximal and distal ends. The body presents a first wide outer surface proximate the distal end, a third wide outer surface proximate the proximal end, and a second wide outer surface axially spaced from and positioned between the first and second wide outer surfaces. The first group of magnets is coupled to the body, circumferentially spaced from one another, and axially positioned between the first and second wide outer surfaces. The second group of magnets is coupled to the body, circumferentially spaced from one another, and axially positioned between the second and third wide outer surfaces. The magnets in the third group of magnets are coupled to the distal end of the body and are spaced-apart from one another.
- In still another embodiment of the present invention, there is provided an elongated downhole tool for inserting radioactive marker bullets into a subterranean formation and retrieving stray radioactive marker bullets not properly penetrating into the formation. The downhole tool comprises a radioactive marker bullet gun having a normally upper end and a normally lower end and a magnetic fishing tool having a proximal end coupled to the normally lower end of the radioactive marker bullet gun. The fishing tool includes a side magnet axially positioned between the proximal and distal ends of the body, and an end magnet positioned proximate the distal end of the tool. The side magnet presents an exposed side surface facing in a first direction and the end magnet presents an exposed bottom surface facing in a second direction. The first direction is within 30 degrees of perpendicular to the direction of extension of the longitudinal axis of the downhole tool. The second direction is within 30 degrees of parallel to the direction of extension of the longitudinal axis.
- In a further embodiment of the present invention, there is provided a wellbore system in a subterranean formation comprising a borehole, a stray radioactive marker bullet, and a fishing tool. The borehole extends downwardly into the subterranean formation. The stray radioactive marker bullet is loosely positioned in the borehole. The fishing tool is positioned in the borehole and includes a plurality of magnets operable to attract and hold the stray radioactive marker bullet so that the stray radioactive marker bullet can be retrieved from the borehole along with the fishing tool.
- In still a further embodiment of the present invention, there is provided a process comprising the steps of: (a) lowering a fishing tool into a borehole in a subterranean formation; (b) traversing the borehole with the fishing tool, thereby causing the fishing tool to be positioned proximate a stray radioactive marker bullet located in the borehole; (c) coupling the stray radioactive marker bullet to the fishing tool by magnetic attraction; and (d) retrieving the fishing tool and the radioactive marker bullet coupled thereto from the borehole.
- A preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein:
- FIG. 1 is an elevation view of a wellbore system in a subterranean formation, particularly illustrating a downhole tool for implanting radioactive marker bullets and retrieving stray radioactive marker bullets lost in the borehole;
- FIG. 2 is a side view of a downhole magnetic fishing tool constructed in accordance of the present invention, particularly illustrating the shape of the main body of the fishing tool as well as the position of the magnets on the body;
- FIG. 3 is an end view of the downhole magnetic fishing tool illustrated in FIG. 2, particularly illustrating the end magnets attached to the distal end of the tool; and
- FIG. 4 is an isometric view of the downhole magnetic fishing tool illustrated in FIGS. 2 and 3.
- Referring initially to FIG. 1, a
wellbore system 10 is illustrated as generally comprising aborehole 12 extending downward into asubterranean formation 14, implanted radioactive marker bullets (RMBs) 16, stray side RMBs 18,stray bottom RMBs 20,stray floating RMB 21, and adownhole tool assembly 22.Downhole tool assembly 22 is received inborehole 12 and is supported by acable 24 which extends intoborehole 12 and is coupled tosurface equipment 26.Cable 24 andsurface equipment 26 cooperate to raise and lowertool assembly 22 inborehole 12. Preferably,cable 24 is a wireline which not only physically supportstool assembly 22, but also includes electrical conductors for carrying power and/or electrical control signals fromsurface equipment 26 totool assembly 22. -
Downhole tool assembly 22 comprises a radioactivemarker bullet gun 28 and amagnetic fishing tool 30.Gun 28 is operable to propel radioactive marker bullets (RMBs) outward and intosubterranean formation 14. Properly implantedRMBs 16 are snugly received insubterranean formation 14 so that any local shifting ofsubterranean formation 14 causes corresponding shifting of implantedRMBs 16 in that location. Althoughgun 28 is designed to fire radioactive marker bullets intosubterranean formation 14, several factors, such as improper operation ofgun 28 and/or extremely high density ofsubterranean formation 14, may cause inadequate lodging of the radioactive marker bullets insubterranean formation 14. Suchstray RMBs stray side RMB 18 b), may fall (e.g., stray floating RMB 21) inborehole 12 and come to rest on a ledge of the sidewall of borehole 12 (e.g.,stray side RMB 18 a), or may simply fall to the bottom of borehole 12 (e.g., stray bottom RMBs 20). -
Magnetic fishing tool 30 is operable to attract and holdstray RMBs 18, 20 which are relatively loosely positioned inborehole 12.Magnetic fishing tool 30 comprises a first group ofside magnets 32, a second group ofside magnets 34 axially spaced from the first group ofside magnets 32, and a group ofend magnets 36.Side magnets borehole 12 so thatstray RMBs 18, 21 can be pulled into contact with and held against the outwardly facing surface ofside magnets End magnets 36 face generally downward toward the bottom ofborehole 12 so thatstray bottom RMBs 20 can be pulled into contact with and held against the downwardly facing surface ofend magnets 36 by magnetic force. - RMBs16, 18, 20, 21 can be any conventional bullet capable of being coupled to
magnets fishing tool 30 by magnetic force. Preferably,RMBs magnets fishing tool 30. Radioactivemarker bullet gun 28 can be any conventional radioactive marker bullet gun capable of propelling radioactive marker bullets intosubterranean formation 14. An example of a suitable radioactive marker bullet gun is the “E-Gun (Bullet) Perforating System” available from Baker Atlas, Houston, Tex. Another radioactive marker bullet gun which can be modified for use withfishing tool 30 is described in U.S. Pat. No. 4,916,312 (assigned to Schlumberger Technology), the entire disclosure of which is incorporated herein by reference. Other suitable radioactive marker bullet gun configurations are well known in the art. - Referring now to FIGS.2-4,
magnetic fishing tool 30 generally comprises an elongatedmain body 38 extending along alongitudinal axis 39 and three groups ofmagnets body 38 at specific axial locations.Body 38 includes aproximal end 40 adapted to be coupled to a radioactive marker bullet gun and adistal end 42 which normally faces downward whenfishing tool 30 is inserted into a borehole.Proximal end 40 preferably includes a male threadedmember 44 forcoupling fishing tool 30 to a normally lower end of a radioactive marker bullet gun. - The outer surface of
main body 38 includes first, second, and third axially spaced wideouter surfaces outer surfaces terminal end surface 58, and a terminal taperedsurface 60. First wideouter surface 46 is located proximatedistal end 42. Third wideouter surface 50 is located proximateproximal end 40. Second wideouter surface 48 is axially spaced from and positioned between first and third wideouter surfaces outer surface 52 is axially positioned between first and second wideouter surfaces outer surface 54 is axially positioned between second and third wideouter surfaces transition surface 56 provides a tapered transition between one of narrowouter surfaces outer surfaces surface 60 provides a tapered transition between first wideouter surface 46 andterminal end surface 58. Preferably, wideouter surfaces outer surfaces surface 60 are substantially frustoconical in shape, andterminal end surface 58 is substantially flat. - First and second groups of
side magnets main body 38 proximate first and second narrowouter surfaces End magnets 36 are coupled tomain body 38 proximateterminal end surface 58. Preferablymagnets main body 38 by inserting each individual magnet into a respective bore inmain body 38. Preferably,magnets Magnets main body 38 by any means known in the art such as, for example, glueing, soldering, or welding.Magnets Magnets - First and second groups of
side magnets outer surface main body 38. Preferably, each of first and second groups ofside magnets side magnets longitudinal axis 39. Each magnet in first and second groups ofside magnets side surface 62. Side surfaces 62 preferably face generally radially away fromlongitudinal axis 39 ofmain body 38. Preferably, eachside surface 62 of each individual magnet in the groups ofside magnets longitudinal axis 39, more preferably within 15 degrees of perpendicular to the direction of extension oflongitudinal axis 39, and most preferably substantially perpendicular to the direction of extension oflongitudinal axis 39. - Wide
outer surfaces outer surfaces longitudinal axis 39 by a maximum radial distance which is greater than the maximum distance betweenlongitudinal axis 39 and side surfaces 62 ofside magnets outer surfaces longitudinal axis 39 than side surfaces 62 ofside magnets side RMB 64 from being disengaged from (i.e., “scraped off”)side surface 62 by the sidewall of the borehole whenfishing tool 30 is shifted up and down in the borehole. Preferably, the maximum radial distance betweenlongitudinal axis 39 and wideouter surfaces longitudinal axis 39 and side surfaces 62 ofside magnets longitudinal axis 39 and wideouter surfaces - Narrow
outer surfaces longitudinal axis 39 and narrowouter surfaces longitudinal axis 39 and wideouter surfaces longitudinal axis 39 and narrowouter surfaces longitudinal axis 39 and side surfaces 62 ofside magnets 32, 34 (i.e., when side surfaces 62 ofside magnets outer surfaces 52, 54). Alternatively, the maximum radial distance betweenlongitudinal axis 39 and narrowouter surfaces longitudinal axis 39 and side surfaces 62 ofside magnets side magnets outer surfaces 52, 54). - Group of
end magnets 36 comprises a plurality of spaced-apart individual magnets. Preferably, group ofend magnets 36 comprises from 1 to 8 individual magnets, more preferably from 2 to 6 individual magnets, and most preferably 3 individual magnets. Eachend magnet 36 presents a substantially flat downwardly-facingbottom surface 66. Bottom surfaces 66 preferably face generally axially away frommain body 38 in a direction which is within 30 degrees of parallel to the direction of extension oflongitudinal axis 39, more preferably within 15 degrees of parallel to the direction of extension oflongitudinal axis 39, and most preferably substantially parallel to the direction of extension oflongitudinal axis 39. The direction in which bottom surfaces 66 ofend magnets 36 face and the direction in which eachside surface 62 ofside magnets side magnets bottom surfaces 66 ofend magnets 36 are preferably exposed (i.e., uncovered) so that radioactive marker bullets located away from side andbottom surfaces bottom surfaces - Referring again to FIG. 1, in operation,
downhole tool assembly 22 can be assembled by couplingmagnetic fishing tool 30 to a normally lower end of radioactivemarker bullet gun 28. A normally upper end of radioactivemarker bullet gun 28 can then be coupled tocable 24.Downhole tool assembly 22 can then be lowered intoborehole 12. Once inborehole 12, radioactive marker bullets (RMBs) can be propelled outwardly fromgun 28 intosubterranean formation 14.Stray RMBs gun 28 but not properly lodged insubterranean formation 14 may fall downward fromgun 28 and towardsmagnetic fishing tool 30. As these stray RMBs (e.g., stray floating RMB 21) fall pastfishing tool 30, they may become attracted by and coupled toside magnets fishing tool 30. Some of the stray RMBs (e.g.,stray side RMB 18 a) may fall pastmagnetic fishing tool 30 and come to rest on ledges of the sidewall ofborehole 12. Other of the stray RMBs (e.g., stray bottom RMBs 20) may fall to the bottom ofborehole 12.Stray RMBs 18, 21 can be pulled into contact with and coupled toside magnets fishing tool 30 whenfishing tool 30 is passed by and/or contacted with stray side RMBs 18.Stray bottom RMBs 20 can be pulled into contact with and coupled to endmagnets 36 whenfishing tool 30 is lowered to the bottom ofborehole 12. Whendownhole tool assembly 22 is removed fromborehole 12, the stray RMBs coupled tomagnets magnetic fishing tool 30 are removed therewith. Thus,downhole tool 22 allows implantedRMBs 16 to be fired intosubterranean formation 14 andstray RMBs borehole 12 during a single run ofdownhole tool assembly 22 inborehole 12. - The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense to interpret the scope of the present invention. Obvious modifications to the exemplary embodiments, set forth above could be readily made by those skilled in the art without departing from the spirit of the present invention.
- The inventor hereby states his intent to rely on the doctrine of equivalence to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from, but outside the literal scope of the invention as set forth in the following claims.
Claims (37)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/096,268 US6629562B1 (en) | 2002-03-12 | 2002-03-12 | Downhole fishing tool for retrieving metallic debris from a borehole |
PCT/US2003/005560 WO2003078942A2 (en) | 2002-03-12 | 2003-02-24 | Radioactive bullet retrieval |
AU2003216387A AU2003216387A1 (en) | 2002-03-12 | 2003-02-24 | Radioactive bullet retrieval |
NO20044293A NO20044293L (en) | 2002-03-12 | 2004-10-11 | Downhole gjenvinningsverktoy |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/096,268 US6629562B1 (en) | 2002-03-12 | 2002-03-12 | Downhole fishing tool for retrieving metallic debris from a borehole |
Publications (2)
Publication Number | Publication Date |
---|---|
US20030173084A1 true US20030173084A1 (en) | 2003-09-18 |
US6629562B1 US6629562B1 (en) | 2003-10-07 |
Family
ID=28038996
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/096,268 Expired - Lifetime US6629562B1 (en) | 2002-03-12 | 2002-03-12 | Downhole fishing tool for retrieving metallic debris from a borehole |
Country Status (4)
Country | Link |
---|---|
US (1) | US6629562B1 (en) |
AU (1) | AU2003216387A1 (en) |
NO (1) | NO20044293L (en) |
WO (1) | WO2003078942A2 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050194132A1 (en) * | 2004-03-04 | 2005-09-08 | Dudley James H. | Borehole marking devices and methods |
WO2011146251A1 (en) * | 2010-05-18 | 2011-11-24 | Baker Hughes Incorporated | Dual-pole magnetic attraction downhole magnetic retrieval apparatus |
WO2011146253A2 (en) * | 2010-05-18 | 2011-11-24 | Baker Hughes Incorporated | Retaining and isolating mechanisms for magnets in a magnetic cleaning tool |
CN102418485A (en) * | 2010-09-27 | 2012-04-18 | 中国石油天然气股份有限公司 | Positionable underground intelligent fishing tool |
US11236568B2 (en) * | 2020-06-17 | 2022-02-01 | Saudi Arabian Oil Company | Powered articulated magnetic fishing tool |
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US7137449B2 (en) * | 2004-06-10 | 2006-11-21 | M-I L.L.C. | Magnet arrangement and method for use on a downhole tool |
US7219724B2 (en) * | 2004-07-15 | 2007-05-22 | Bilco Tools, Inc. | Downhole magnetic retrieval tool |
US7398823B2 (en) * | 2005-01-10 | 2008-07-15 | Conocophillips Company | Selective electromagnetic production tool |
US7357183B2 (en) * | 2005-09-09 | 2008-04-15 | Venturi Oil Tools | Magnetic fishing tool and method |
NO327278B1 (en) * | 2007-06-26 | 2009-06-02 | Mi Swaco Norge As | Magnetic mounting device in a downhole cleaning tool |
US20090211816A1 (en) * | 2008-02-26 | 2009-08-27 | Terril Bryan Williams | Magnetic bit sub |
US7753114B1 (en) * | 2008-05-01 | 2010-07-13 | Penisson Dennis J | Magnetic wellbore cleaning tool |
US8230934B2 (en) | 2009-10-02 | 2012-07-31 | Baker Hughes Incorporated | Apparatus and method for directionally disposing a flexible member in a pressurized conduit |
US8573297B2 (en) | 2010-03-09 | 2013-11-05 | Conocophillips Company | Subterranean formation deformation monitoring systems |
US8839856B2 (en) | 2011-04-15 | 2014-09-23 | Baker Hughes Incorporated | Electromagnetic wave treatment method and promoter |
CA3015472C (en) | 2013-11-05 | 2021-08-10 | Weatherford Technology Holdings, Llc | Magnetic retrieval apparatus |
CA3007884A1 (en) * | 2015-12-28 | 2017-07-06 | Shell Internationale Research Maatschappij B.V. | Use of a spindle to provide optical fiber in a wellbore |
US10738554B2 (en) | 2018-06-08 | 2020-08-11 | Saudi Arabian Oil Company | Repulsion force systems and methods for metal fish retrieval |
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US2857970A (en) * | 1954-07-02 | 1958-10-28 | Orren B Hopkins | Magnetic fishing tool |
US2834630A (en) | 1955-03-16 | 1958-05-13 | Warner W Greer | Magnetic fishing tool |
US3905631A (en) | 1974-05-13 | 1975-09-16 | Tom E Ricks | Magnetic fishing tool |
US4084636A (en) | 1976-08-26 | 1978-04-18 | Burge Edward V | Hydraulic junk retriever |
US4226285A (en) | 1979-02-12 | 1980-10-07 | Moseley Jr Meekie D | Magnetic junk retriever |
FR2611921B1 (en) | 1987-03-05 | 1989-06-16 | Schlumberger Prospection | DEVICE FOR PLACING A RADIOACTIVE SOURCE IN A FORMATION CROSSED BY A WELL |
FR2640530B1 (en) * | 1988-12-20 | 1992-01-31 | Fmc Europe | SCRAPER FOR LIQUID DISTRIBUTION PIPE, ESPECIALLY FOR OIL PRODUCTS |
CA2259776C (en) * | 1999-01-21 | 2001-07-31 | Ian B. Zeer | Magnetic assembly for use with a downhole casing perforator |
US6216787B1 (en) | 1999-10-21 | 2001-04-17 | Rattler Tools, Inc. | Apparatus for retrieving metal objects from a wellbore |
-
2002
- 2002-03-12 US US10/096,268 patent/US6629562B1/en not_active Expired - Lifetime
-
2003
- 2003-02-24 WO PCT/US2003/005560 patent/WO2003078942A2/en not_active Application Discontinuation
- 2003-02-24 AU AU2003216387A patent/AU2003216387A1/en not_active Abandoned
-
2004
- 2004-10-11 NO NO20044293A patent/NO20044293L/en not_active Application Discontinuation
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050194132A1 (en) * | 2004-03-04 | 2005-09-08 | Dudley James H. | Borehole marking devices and methods |
US7204308B2 (en) | 2004-03-04 | 2007-04-17 | Halliburton Energy Services, Inc. | Borehole marking devices and methods |
WO2011146251A1 (en) * | 2010-05-18 | 2011-11-24 | Baker Hughes Incorporated | Dual-pole magnetic attraction downhole magnetic retrieval apparatus |
WO2011146253A2 (en) * | 2010-05-18 | 2011-11-24 | Baker Hughes Incorporated | Retaining and isolating mechanisms for magnets in a magnetic cleaning tool |
WO2011146253A3 (en) * | 2010-05-18 | 2012-02-23 | Baker Hughes Incorporated | Retaining and isolating mechanisms for magnets in a magnetic cleaning tool |
CN102418485A (en) * | 2010-09-27 | 2012-04-18 | 中国石油天然气股份有限公司 | Positionable underground intelligent fishing tool |
US11236568B2 (en) * | 2020-06-17 | 2022-02-01 | Saudi Arabian Oil Company | Powered articulated magnetic fishing tool |
Also Published As
Publication number | Publication date |
---|---|
US6629562B1 (en) | 2003-10-07 |
NO20044293L (en) | 2004-12-13 |
WO2003078942A2 (en) | 2003-09-25 |
WO2003078942A3 (en) | 2004-08-05 |
AU2003216387A1 (en) | 2003-09-29 |
AU2003216387A8 (en) | 2003-09-29 |
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