EP0209217B1 - Dispositif et procédé d'exécution d'un forage courbe et d'installation d'une conduite dans ce forage - Google Patents

Dispositif et procédé d'exécution d'un forage courbe et d'installation d'une conduite dans ce forage Download PDF

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Publication number
EP0209217B1
EP0209217B1 EP86303324A EP86303324A EP0209217B1 EP 0209217 B1 EP0209217 B1 EP 0209217B1 EP 86303324 A EP86303324 A EP 86303324A EP 86303324 A EP86303324 A EP 86303324A EP 0209217 B1 EP0209217 B1 EP 0209217B1
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EP
European Patent Office
Prior art keywords
drill
leading
string
pipe
bore hole
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.)
Expired - Lifetime
Application number
EP86303324A
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German (de)
English (en)
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EP0209217A2 (fr
EP0209217A3 (en
Inventor
Martin D. Cherrington
William D. Cherrington
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Cherrington Corp
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Cherrington Corp
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Publication date
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Publication of EP0209217A3 publication Critical patent/EP0209217A3/en
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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
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/02—Couplings; joints
    • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
    • E21B17/042—Threaded
    • 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
    • E21B10/00—Drill bits
    • E21B10/60—Drill bits characterised by conduits or nozzles for drilling fluids
    • 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
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • E21B7/06—Deflecting the direction of boreholes
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • E21B7/06—Deflecting the direction of boreholes
    • E21B7/065—Deflecting the direction of boreholes using oriented fluid jets
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • E21B7/06—Deflecting the direction of boreholes
    • E21B7/068—Deflecting the direction of boreholes drilled by a down-hole drilling motor
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/18—Drilling by liquid or gas jets, with or without entrained pellets
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
    • E21B7/208—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes using down-hole drives
    • 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
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/28—Enlarging drilled holes, e.g. by counterboring

Definitions

  • the present invention relates to an apparatus and method for drilling a pilot bore hole along an underground arcuate path between two surface locations, and then enlarging the pilot bore hole for installing a conduit therein, such as pipe, casing, cable, or a pipeline.
  • directional drilling apparatus for drilling an underground pilot bore hole along an arcuate path between two surface locations, and then enlarging the pilot bore hole for receiving a product conduit, such as a pipeline therein.
  • a common apparatus and method has utilized a drill pipe string of a relatively small diameter less than two inches (2" (5.1 cm)) with a drill bit thereon forming a relatively small diameter pilot bore hole, which is followed by a relatively large diameter washover pipe such as around five inches (5" (12.7 cm)) in diameter or more, in concentric relation to the drill string and having cutting blades on the leading end thereof for enlarging the initial pilot bore hole.
  • the drill string Upon completion of the pilot bore hole as enlarged by the washover pipe, the drill string has been removed and the washover string then connected to a reamer at the exit end for pulling the reamer and connected product conduit along the initial bore hole for reaming to a desired diameter to receive the product conduit.
  • the method and apparatus employed heretofore for forming a pilot bore hole normally has included two separate cutting or drilling steps prior to the reaming operation, the first cutting step being the drilling of a small diameter bore hole from a drill bit with a relatively small diameter light weight drill string, and the second cutting step resulting from an enlarging of the bore hole by the washover string in concentric relation to the drill string. Thereafter, the reaming operation has taken place to enlarge the pilot bore hole to receive the product conduit or pipe.
  • a relatively small diameter drill pipe string of around one and three-fourths inches (1-3/4" (4.46 cm)) in diameter has been utilized for such pilot bore holes as it was found desirable to have a relatively lightweight drill pipe or string, particularly when drilling under streams where sand and clays are normally encountered with water also being present at times.
  • the drill string could sink under certain conditions and it was accepted as common practice in the industry to employ a relatively small diameter drill string in order to keep the weight of the entire drill string at a minimum and to provide flexibility.
  • Such a small diameter drill pipe string thus necessitated the use of a separate washover string in order to provide the necessary strength for the subsequent reaming operation and pulling of the production conduit through the enlarged bore hole.
  • apparatus for drilling an arcuate underground pilot bore hole in one direction of travel along an inverted arcuate path between two spaced surface locations, a first location being an entry location, and a second location being an exit location without further cutting said pilot bore hole in said one direction of travel to accommodate a washover pipe string and without otherwise utilising a washover pipe string, and then reaming in an opposite direction of travel an enlarged opening along the pilot bore hole, while simultaneously placing a production conduit within the enlarged bore hole
  • said apparatus including a drill pipe string including a plurality of pipe sections connected end to end and extending from said entry location into said pilot bore hole, said drill pipe string having a leading pipe section, with a drill bit attached thereto, means to circulate drilling fluid during the drilling operation, means at said first location to apply a thrust on said drill pipe string to force said drill pipe string along said arcuate path to said exit location, a reamer connected to said drill string at said exit location after the pilot bore hole is drilled between said spaced surface locations, to
  • the apparatus and method use two separate cutting operations, the first being a pilot bore drilled by a conventional drill pipe string but utilising at least for a majority of the drill pipe section an increased diameter of around three and one-half inches (3-1/2" (8.89 cm)) which increases the strength of the pipe string as compared with common industry practice heretofore.
  • the increased strength drill string thus eliminates the necessity of having a separate washover string as the increased drill string strength is adequate for the torsional or rotational stresses developed in the subsequent reaming operation and pulling of the production conduit through the enlarged bore hole.
  • the drill string is thrust along a predetermined arcuate path to form an initial pilot bore hole of a relatively small diameter, such as around five inches (5" (12.7 cm)), for example.
  • a reamer and connected production conduit are attached to the drill string, and the drill string is then pulled back through the pilot bore hole in an opposite direction of travel with the reamer enlarging the bore hole to a diameter sufficient to receive the production conduit therein.
  • the enlarged opening may be around thirty inches (30" (76.2 cm))in diameter for a production conduit, such as a pipeline, around twenty inches (20" (50.8 cm)) in diameter thereby providing a five inch (5" 12.7 cm)) annulus between the production conduit and the enlarged opening.
  • the leading end pipe section having the drill bit thereon may be provided of a diameter smaller than the diameter of the regular drill string sections, or a different wall thickness or different type of material may be utilized for the leading pipe section to provide the desired flexibility.
  • the drill string sections except for the leading pipe sections are over around three inches (3" (7.6 cm)) in diameter and sections of three and one-half inches (3-1/2" (8.89 cm) in diameter have been found satisfactory.
  • the leading drill pipe section of this invention is preferably below three inches (3" (7.6 cm) in diameter.
  • the leading drill pipe section or sections may be provided with an increased flexibility and the length of the leading end section may be varied.
  • Any reduced diameter drill pipe section or sections are preferably removed at the surface location adjacent the exit opening prior to the attachment of the reamer and production conduit to the drill string.
  • a constant diameter drill string may be provided for pulling the reamer and following product conduit through the pilot bore hole in a reverse or opposite direction of travel.
  • drill pipe sections in the drill string of an increasing strength from the leading end thereof to the power means for thrusting the drill bit and/or rotating the drill string in the reaming operation.
  • the increased strength pipe sections compensate for the increasing friction of the drill string along its length.
  • Drill pipe sections having an increased strength may be provided independently of any increased flexibility, if desired. In some situations, it may be desirable to have less flexibility on the leading end drill pipe sections.
  • Another feature of this invention utilizes an in-hole hydraulic motor positioned within the leading drill string section for rotating the drill bit, such as might be desirable where relatively hard formations are encountered.
  • the longitudinal axis of the drive shaft for rotating the drill bit is parallel to but offset from the longitudinal axis of the drill string. This offset results in the deviation or deflection of the drill bit a predetermined amount in the desired direction of travel as the leading pipe section rides along the surface of the pilot bore hole formed by the drill bit opposite the desired direction of deviation.
  • Fig. 1 in which an arcuate pilot bore hole is illustrated at B extending along an underground path shown at P.
  • Path P extends from an earth surface entrance opening O to an earth surface exit opening E underneath an obstruction shown as a river R.
  • exit opening E is shown as a surface exit opening in the drawings, the terms “exit opening”, “surface exit opening” or “surface location” as used in the specification and claims shall be interpreted as including an opening beneath the surface at which a product conduit is connected to the drill string to be pulled through the bore hole, such as an underground cable.
  • a drill string indicated generally at 10 includes a leading end pipe section 10A of a small diameter, an adjacent end section 10B of an intermediate diameter, and following pipe sections 10C of uniform diameter. Drill string 10 is utilized to drill small diameter pilot bore hole B along path P. A plurality of lengths or sections of pipe string 10 are normally positioned adjacent entrance opening O such as shown at 10C in broken lines in Fig. 1.
  • drill string pipe sections utilized heretofore in association with a separate washover pipe string have been of a diameter around one and three-fourths inches (1-3/4" (4.45 cm) since the washover string was relied upon for rotation of the reamer and pulling of the production conduit.
  • the present invention eliminates the washover pipe and instead, provides a higher strength drill pipe string having a diameter of three and one-half inches (3-1/2" (8.89 cm). Such an increased diameter provides a stiffer pipe string than used heretofore.
  • sections 10C are of the normal or regular diameter of three and one-half inches (3-1/2" (8.89 cm)).
  • leading section 10A is formed of a smaller diameter pipe and is around two and three-quarters inches (2-3/4" (6.99 cm) in diameter, while pipe section 10B is of an intermediate diameter of two and seven-eighths inches (2-7/8" (7.30 cm)).
  • sections 10A and 10B could, if desired, provide increased flexibility by other means, such as by being made of a more flexible high strength material without being of a reduced diameter, or by having a different wall thickness without any change in external diameter.
  • a relatively long arcuate path P it is also desirable for a relatively long arcuate path P to have trailing pipe sections of the drill string of a strength greater than the leading pipe sections.
  • the drill string is pushed from the entrance opening O along the bore hole B, and portions of the length of the drill string are in contact with the surface of the bore hole B during the pushing action thereby to generate sliding frictional resistance which has to be overcome.
  • the greater the length of the drill string the greater the amount of sliding friction.
  • the torsional or rotational stresses in the drill string are higher at the power source providing rotation.
  • drill pipe sections of graduated increasing strength from the drill bit end to the power source. Further, it may not be desirable to have the diameter of the drill string greater than around three and one-half inches (3-1/2" (8.89 cm)), or to have the leading pipe sections of an increased flexibility. Under such conditions, the strength of the drill pipe sections, particularly those sections adjacent the power means for thrusting the drill bit along a relatively long arcuate path P, such as over five hundred feet (500' (152.4 m)) in length, are preferably of an increased strength. Such increased strength could be provided, for example, by making the pipe sections of high strength materials or increasing the wall thickness of such pipe sections. The utilization of drill pipe sections with different strengths thereby eliminates the necessity of having a separate washover pipe following the drill string in concentric relation, as a specific drill string section can be designed for the specific strength required at its location in a drill string.
  • an inclined ramp is shown at 12 and has a hydraulic motor 14 mounted on a carriage 16 for axial movement along a suitable guideway on ramp 12, such as by a suitable pulley or cog wheel 18 moving along a taut cable 20, for example.
  • Motor 14 may be used, selectively, to rotate a connecting shaft 22 which is connected at one end to a joint 24 attached to section 10C of drill string 10, thereby to rotate drill string 10, if desired.
  • Shaft 22 is connected at its other end to a swivel 26 which is in turn connected to a hose 28 through which a suitable drilling fluid is circulated.
  • Carriage 16 reciprocates back and forth as drill pipe sections are added by making and breaking joint 24.
  • Drilling mud circulated through hose 28 is supplied to the drill pipe and out suitable fluid passageways (not shown) at the drill bit for possible return to a sump shown at 30 adjacent the end of entrance opening O which receives the drilling fluid and cuttings from the drilling operation.
  • a suitable hose shown at 32 returns the drilling fluid or mud for removal of the cuttings, and again providing drilling fluid to hose 28 as is well known in the art.
  • Drill string 10 is standard and normally made up of a plurality of drill pipe sections which are added to the drill pipe string at connector 24.
  • the pipe sections are advanced in the earth by advancing hydraulic motor 14 connected to a suitable source of hydraulic fluid (not shown) down ramp 12.
  • Leading small diameter pipe section 10A has a spud bit 34 on its leading end.
  • Spud bits of various types are well known generally in the art for directional drilling or the like.
  • spud bit 34 as shown in Figs. 5 and 5A is particularly adapted in the present invention for discharging a high velocity drilling fluid from its leading end at a location closely adjacent the formation thereby to obtain a highly effective excavating action to advance the drill string. It is important to note that spud bit 34 preferably discharges fluid in a direction parallel to the axis of the drill string as shown by the arrows in Fig. 5.
  • spud bit 34 has a flat or planar forward end portion 34A, an inclined intermediate planar end portion 34B leading from forward end portion 34A to form a ramp, and a rear planar shoulder 34C.
  • An arcuate shoe or wear plate 35 is secured to the outer periphery of pipe section 10A adjacent rear shoulder 34C. It is noted that bore hole B has a diameter larger than the maximum diameter of any portion of the drill string moving through the hole.
  • a discharge opening 34D or discharge nozzle which may be threaded within end portion 34A to form opening 34D is provided in the face formed by planar end portion 34A.
  • opening 34D is positioned at the leading end of spud bit 34 directly adjacent the formation to be excavated for discharging a jet of high velocity drilling fluid therein.
  • the drilling fluid may be pressurized from around one hundred pounds per square inch (100 psi/689.5x103Nm ⁇ 2) to around two thousand pounds per square inch (2000 psi/13.8x106Nm ⁇ 2), for example.
  • the longitudinal or discharge axis of discharge nozzle 34D is parallel to, but offset from, the longitudinal axis of drill string 10 to aid in deflecting end section 10A in the direction of the offset.
  • Discharge opening 34D is of sufficient depth such that pressurized fluid is preferably discharged therefrom in a direction parallel to the longitudinal axis of drill string 10 to erode and/or excavate the formation. It is apparent that end section 10A may be guided also by rotation of the drill string through a defined angle.
  • the offset of nozzle or opening 34D, or the offset of the center of the volume of fluid being discharged in the event more than one discharge opening is utilized should be at least greater than around threefourths inch (3/4" (1.91 cm)).
  • nozzle 34D is around threeeighths inch (3/8" (0.95cm)) in diameter and offset one inch (1" (2.54cm)) from the longitudinal center line of section 10A.
  • the center of the combined jets of drilling fluid being discharged is parallel to and preferably offset from the longitudinal axis of section 10A in the desired travel path.
  • the ramp formed by inclined planar end portion 34B, rear shoulder 34C, and shoe 35 ride along the surface of bore hole B opposite the desired direction of deviation and aid in guiding pipe section 10A along travel path P.
  • Spud bit 34 thus moves along path P in a thrusting action without being rotated except for a predetermined partial rotation to obtain angular orientation to guide pipe section 10A.
  • spud bit 34 has been developed primarily for use in drilling a pilot bore hole along an arcuate path between two surface locations, it is obvious that spud bit 34 may be utilized for other types of directional or down-hole drilling as well known in the art.
  • Arcuate path P can be controlled or guided without withdrawing of the drill string from the earth primarily by orientation of spud bit 34 by a partial rotation of the drill string through a defined angle, but such control may also be dependent on such factors or parameters, for example, as the thrust on the drill string and the volume of drilling mud passed to the drill string, as is well known in the art.
  • control may also be dependent on such factors or parameters, for example, as the thrust on the drill string and the volume of drilling mud passed to the drill string, as is well known in the art.
  • a crossover sub indicated generally at 36 is illustrated having a threaded male end 38 adapted to be threaded within a female end 40 on pipe section 10A, and having a female connection 42 on an opposite end thereof adapted to receive the male threaded end 44 of adjacent pipe section 10B.
  • a similar crossover sub 42 is provided between sections 10B and 10C.
  • the diameter of bore B is sufficiently larger than the diameter of pipe string 10 to provide an annulus to permit the discharge of the drilling fluid and cuttings from bore B. Utilizing a drill pipe string of a maximum diameter around three and one-half inches (3-1/2" (8.89 cm)) bore B may be around five inches (5" (12.7cm)) in diameter to provide adequate clearance for the flow of cuttings and drilling fluid from bore B.
  • the production conduit may be any of several types of continuous conduit, such as, for example, casing, pipe, cables, or the like, and more than one production conduit may be installed in enlarged opening D.
  • a reamer indicated generally at 48 is shown in Fig. 6. Reamer 48 has cutting teeth 50 thereon and is coupled at 52 to the end of the first drill section 10C of the uniform diameter of three and one-half inches (3-1/2" (8.89)) for rotation by drill string 10 and motor 14.
  • the end drill pipe section 10A is removed for connection of drill string 10 to reamer 48. It may be desirable to remove both sections 10A and 10B from the end of the drill string 10 prior to the connection of reamer 48 if it is desired that drill string 10 be of a uniform diameter and strength for rotating reamer 48 and pulling production pipe 46 through bore hole B.
  • Drilling mud continues to be supplied through drill string 10 and pipe section 10C to the cutting area adjacent reamer 48 where it is discharged through suitable perforations as is well known.
  • Shaft 54 extends from reamer 48 and has an enlarged diameter end thereof at 56 received within a swivel indicated generally at 50 so that reamer 48 can rotate relative to production pipe 46.
  • An equally satisfactory and effective method and means could be utilized by a separate threaded sleeve connection between shaft 54 and reamer 48 as shown in Fig. 3 by connector 24.
  • Enlarged end 56 of shaft 54 is mounted within bearings 58 on opposite sides thereof for transmitting thrust to swivel 50 and to permit relative rotation between reamer 48 and production pipe 46.
  • Swivel body 50 has a clevis defining two spaced arms 60 on the side thereof opposite shaft 54, and an extension 62 on a sleeve 66 is pivotally connected to arms 60 by pin or bolt 64.
  • Sleeve 66 is shown in Fig. 6 threaded onto an end of production pipe 46 which is formed of a plurality of welded sections as common for pipelines. It is to be understood, however, as well known in the art, that sleeve 66 could be secured by other means to a production conduit, such as, for example, by welding, bolted connection, or other types of threaded connections.
  • Reamer 48 is of a diameter larger than a diameter of production casing 46 so as to form a suitable annulus 68 in the enlarged diameter opening D.
  • reamer 48 may be of a thirty inch (30" (76.2 cm)) diameter to provide a five inch (5" (12.7 cm)) annulus 68 about the periphery of pipe 46.
  • Annulus 68 may be utilized for cementing of conduit 46 in position.
  • FIG. 7 a modified form of end section is shown at 10D for an in-hole motor 70 which is used where relatively hard formations may be encountered.
  • In-hole motor shown at 70 is positioned within an enlarged diameter end portion 71 of drill string section 10D and is a hydraulic motor driven by drilling fluid received by the drill string.
  • the longitudinal axis of the drill string is shown along line 72 while the longitudinal axis of the rotating drill bit shaft 74 is shown at 76.
  • a drill bit 78 is connected to the end of shaft 74 for rotation therewith.
  • hydraulic motor 70 is shown schematically in Fig. 7 as being separate and larger than shaft 74, it is to be understood, as well known in the art, that motor 70 and shaft 74 may be combined and of a single continuous diameter such as illustrated schematically by shaft 74.
  • axis 76 is offset from but parallel to axis 72 to aid in deflecting end section 10D a predetermined amount in the desired direction of travel. While axis 76 is shown as offset above axis 72 in Fig. 7 to deflect end section 10D upwardly, it may be offset laterally or downwardly by limited rotation of the drill string through a defined angle if a different path of travel is desired. It is noted that other parameters may be utilized to aid in the control of direction of the drill string along the desired travel path P as indicated above for the embodiment shown in Fig. 5, and, in addition, the speed of rotation of drill bit 78.
  • Enlarged diameter end portion 71 has a beveled leading end 79 which rides along the surface 80 of bore B opposite the direction of the offset and as a result of the offset directs bit 78 in the direction of the offset.
  • the amount of offset along with the other parameters set forth for the embodiment of Fig. 5, and the speed of rotation of drill bit 78, determine the amount of deviation or deflection.
  • Motor 70 as well known in the art, has a conventional stator and rotor with drive shaft 74 connected to the rotor. Drilling fluid passes through the rotor and stator to effect a rotation of shaft 74 and drill bit 78, as well known in the art.
  • bore hole B formed by drill bit 78 is illustrated diagrammatically in Fig. 7 of a diameter not greater than the diameter of enlarged end portion 71, it is to be understood that the diameter of bore hole B formed by bit 78 is always of a diameter greater than the diameter of end portion 71 in order to provide a suitable annulus for the flow of drilling fluid and cuttings from drill bit 78.

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Claims (29)

  1. Dispositif pour forer un trou pilote souterrain courbe (B) dans un sens de progression le long d'une trajectoire courbe inversée entre deux sites de surface espacés, un premier site (O) étant un site d'entrée et un second site (E) étant un site de sortie, sans autre creusement dudit forage pilote dans ledit sens de progression pour loger un train de tubes de gainage et sans autre utilisation d'un train de tubes de gainage, et en taillant ensuite, dans un sens de progression opposé, une ouverture agrandie le long du forage pilote (B) tout en plaçant simultanément une conduite de production (46) à l'intérieur du forage agrandi, ledit dispositif comprenant un train de tubes de forage (10) comportant une pluralité de tronçons tubulaires reliés bout à bout et s'étendant à partir dudit site d'entrée dans ledit forage pilote, ledit train de tubes de forage ayant un tronçon tubulaire de tête, avec une mèche de forage fixée à celui-ci, des moyens (14) pour faire circuler un fluide de forage pendant l'opération de forage, des moyens (14) audit premier site (O) pour exercer une poussée sur ledit train de tubes de forage (10) pour forcer ledit train de tubes de forage (10) le long de ladite trajectoire courbe jusqu'audit site de sortie (E), un trépan aléseur (48) relié audit train de forage audit site de sortie (E) après que le forage pilote ait été réalisé entre lesdits sites de surface espacés, pour former une ouverture agrandie le long du forage pilote; une conduite de production (46) reliée audit trépan aléseur (48) et suivant ledit trépan aléseur (48) à travers l'ouverture agrandie formée par le trépan aléseur (48); lesdits moyens (14) audit premier site comprenant des moyens pour tirer ledit train de forage (10), ledit trépan aléseur (48) et ladite conduite de production (46) le long de l'ouverture agrandie dans un sens de progression opposé, lesdits moyens de tirage (14) audit premier site faisant tourner ledit train de forage (10) et ledit trépan aléseur (48) en même temps que l'action de tirage; et lesdits moyens (14) pour faire circuler un fluide de forage fournissant un fluide de forage pour ledit trépan aléseur (48) pendant l'opération d'alésage, caractérisé en ce que
       la mèche de forage montée sur ledit tronçon tubulaire de tête (10A) comprend un trépan d'attaque (34),
       ledit tronçon tubulaire de tête (10A) portant ladite mèche de forage présente une flexibilité plus grande que la flexibilité des autres tronçons tubulaires composant le train de tubes de forage (10), et
       lesdits tronçons tubulaires restants voisins desdits moyens (14) pour exercer une poussée présentent une résistance plus grande que ledit tronçon tubulaire (10A) à l'extrémité de tête dudit train de tubes de forage (10).
  2. Dispositif suivant la revendication 1, caractérisé en ce que la flexibilité accrue dudit tronçon tubulaire de tête (10A) est obtenue par un diamètre dudit tronçon tubulaire de tête (10A) plus petit que celui des autres tronçons tubulaires composant le train de tubes de forage (10).
  3. Dispositif suivant la revendication 2, caractérisé en ce qu'un élément de jonction (36) relie le tronçon tubulaire de tête (10A) au tronçon tubulaire voisin (10B).
  4. Dispositif suivant la revendication 2, caractérisé en ce que le tronçon tubulaire de tête (10A) et le tronçon tubulaire immédiatement voisin (10B) ont tous deux un diamètre inférieur à celui du reste des tronçons tubulaires pour former ainsi une extrémité flexible de relativement grande longueur pour le train de forage (10).
  5. Dispositif suivant la revendication 2, caractérisé en ce que le diamètre du tronçon tubulaire de tête (10A) est inférieur à 7,6 cm (3 pouces).
  6. Dispositif suivant l'une ou l'autre des revendications précédentes, caractérisé en ce qu'un pivot raccorde ledit trépan aléseur (48) et ladite conduite de production (46) pour permettre un mouvement de rotation de l'un par rapport à l'autre.
  7. Dispositif suivant l'une ou l'autre des revendications précédentes, caractérisé en ce que ledit tronçon tubulaire de tête (10A) a un diamètre inférieur au diamètre des tronçons tubulaires voisins desdits moyens (14) pour exercer une poussée.
  8. Dispositif suivant la revendication 1, caractérisé en ce que ledit tronçon tubulaire de tête (10A) a le même diamètre que les tronçons tubulaires restants qui composent le train de tubes de forage (10), mais qu'il a une épaisseur de paroi réduite.
  9. Dispositif suivant la revendication 1, caractérisé en ce que ledit tronçon tubulaire de tête (10A) a le même diamètre que les tronçons tubulaires restants qui composent le train de tubes de forage (10) mais est constitué d'une matière à haute résistance plus flexible qu'au moins la majorité des tronçons tubulaires restants.
  10. Dispositif suivant l'une ou l'autre des revendications précédentes, caractérisé en ce que ledit train de tubes de forage (10) comprend une pluralité de tronçons tubulaires filetés attachés l'un à l'autre, lesdits tronçons tubulaires attachés l'un à l'autre comportant des tronçons tubulaires de résistances différentes.
  11. Dispositif suivant la revendication 10, caractérisé en ce qu'au moins certains des tronçons tubulaires de tête (10A, 10B) ont une résistance réduite par rapport à au moins certains des tronçons tubulaires suivants qui composent le train de tubes de forage (10), et au moins certains des tronçons tubulaires de tête (10A, 10B) présentent une flexibilité accrue par rapport à au moins certains des tronçons tubulaires suivants qui composent le train de tubes de forage (10).
  12. Dispositif suivant la revendication 1, caractérisé en outre par des moyens reliant activement la conduite de production (46) au trépan aléseur (48).
  13. Dispositif suivant la revendication 1, caractérisé en ce que la majorité des tronçons tubulaires dans ledit train de tubes de forage (10) ont un diamètre supérieur à 7,6 cm (3 pouces).
  14. Dispositif suivant l'une ou l'autre des revendications précédentes, caractérisé en ce que le train de tubes de forage (10) comprend une pluralité de tronçons tubulaires filetés attachés l'un à l'autre (10A, 10B, 10C), ledit train comportant des tronçons tubulaires de résistances différentes, et en ce que ledit trépan d'attaque (34) a une extrémité antérieure plane formant une face antérieure plate (34A) de celui-ci, ladite face antérieure plate (34A) présentant une ouverture d'éjection (34D) pour recevoir et éjecter le fluide de forage à grande vitesse directement dans la formation voisine, et une portion plane intermédiaire (34B) inclinée vers l'arrière à partir de ladite face antérieure plate (34A) pour glisser le long de la surface du trou de forage.
  15. Dispositif suivant la revendication 14, caractérisé en outre par un sabot arrondi (35) fixé au pourtour extérieur du tronçon tubulaire de tête (10A) au voisinage dudit trépan d'attaque (34) pour glisser le long d'une surface du trou de forage.
  16. Dispositif suivant la revendication 15, caractérisé en outre en ce que ledit trépan d'attaque (34) présente un épaulement inférieur plan (34C) adjacent audit sabot arrondi (35) pour glisser le long d'une surface du trou de forage.
  17. Dispositif suivant la revendication 1, caractérisé en outre en ce que ledit trépan d'attaque (34) monté sur le tronçon tubulaire de tête (10A) dudit train de tubes de forage (10) présente une face frontale antérieure plate (34A) et des moyens formant buse d'éjection de fluide (34D) dans ladite face frontale antérieure plate (34A) pour éjecter le fluide de forage en un jet ayant son centre déporté par rappoprt à l'axe longitudinal dudit tronçon tubulaire de tête (10A) afin d'aider à guider le train de tubes de forage (10) le long de la trajectoire courbe prédéterminée, ledit tronçon tubulaire de tête (10A) et ledit trépan d'attaque (34) étant aptes à être partiellement tournés d'un angle prédéterminé pour changer le sens de déport desdits moyens formant buse (34D) et la déviation du tronçon tubulaire de forage de tête (10A).
  18. Dispositif suivant la revendication 17, caractérisé en outre en ce qu'un sabot arrondi (35) est fixé au pourtour extérieur du tronçon tubulaire de tête (10A) au voisinage dudit trépan d'attaque (34) pour glisser le long de la surface du trou de forage du côté opposé au sens de déviation désiré.
  19. Dispositif suivant la revendication 17, caractérisé en outre en ce que ledit trépan d'attaque (34) présente un épaulement plan inférieur (34C) adjacent audit sabot arrondi (35) pour glisser le long de la surface du trou de forage du côté opposé au sens de déviation désiré.
  20. Dispositif suivant la revendication 17, caractérisé en ce que la face frontale antérieure plate (34A) dudit trépan d'attaque (34) est une face plane s'étendant dans un plan généralement transversal par rapport à l'axe longitudinal du train de forage et ayant une pluralité de buses d'éjection (34D) dans celle-ci pour éjecter un fluide de forage en jets directement contre la formation, le centre de la masse de fluide éjecté étant déporté par rapport à l'axe longitudinal du train de tubes de forage (10).
  21. Dispositif suivant la revendication 17, caractérisé en ce que la face frontale antérieure plate (34A) dudit trépan d'attaque (34) est une face plane s'étendant dans un plan généralement transversal par rapport à l'axe longitudinal du train de tubes de forage (10), et en ce que ledit trépan d'attaque (34) présente une surface inférieure plane inclinée (34B) s'étendant à partir de ladite face frontale antérieure plate (34A), laquelle surface inférieure plane inclinée (34B) est apte à glisser le long de la surface inférieure du trou de forage pilote.
  22. Procédé pour forer un trou pilote souterrain courbe le long d'une trajectoire prédéterminée dans un sens de progression entre deux sites de surface, un premier desdits sites définissant un site d'entrée (O) et un second desdits sites définissant un site de sortie (E), sans autre creusement dudit forage pilote dans ledit sens de progression pour loger un train de tubes de gainage et sans autre utilisation d'un train de tubes de gainage, et en agrandissant ensuite le forage pilote dans un sens de progression opposé entre les sites de surface pour recevoir une conduite de production à l'intérieur dudit forage agrandi, ledit procédé comprenant les opérations consistant à prévoir un train de tubes de forage (10) composé de tronçons tubulaires attachés l'un à l'autre, comportant un tronçon tubulaire de tête (10A), ledit tronçon tubulaire de tête (10A) ayant un trépan de forage monté sur une portion de tête de celui-ci; à faire circuler un fluide de forage à travers ledit train de tubes de forage (10) pendant ladite opération de forage; à procurer des moyens de poussée (14) audit site d'entrée pour faire avancer le train de tubes de forage portant le trépan de forage depuis ledit site d'entrée (O) jusqu'audit site de sortie (E); à faire avancer ledit train de tubes de forage (10) dans un sens de progression le long de ladite trajectoire courbe depuis ledit site d'entrée (O) jusqu'audit site de sortie (E); à enlever ledit trépan de forage dudit train de tubes de forage (10) après sa sortie audit site de sortie (E), et à attacher audit train de tubes de forage (10), sur ledit site de sortie (E), un trépan aléseur (48) auquel est attaché au moins un tronçon d'une conduite de production (46); à tirer dans le sens de progression opposé et simultanément à faire tourner ledit train de tubes de forage (10) et ledit trépan aléseur (48) en formant une ouverture agrandie apte à recevoir ladite conduite de production (46); et à faire circuler un fluide de forage supplémentaire à travers ledit train de tubes de forage (10) pendant l'opération d'alésage; ledit procédé étant caractérisé en ce que:
       on choisit ledit tronçon tubulaire de tête (10A) de façon telle qu'il ait une flexibilité supérieure à la flexibilité des tronçons tubulaires restants qui composent le train de forage (10),
       on prévoit un trépan d'attaque (34) sur le tronçon tubulaire de tête (10A),
       on choisit des tronçons tubulaires voisins desdits moyens (14) pour exercer une poussée de façon telle que lesdits tronçons tubulaires voisins desdits moyens (14) pour exercer une poussée aient une résistance plus grande que ledit tronçon tubulaire (10A) à l'extrémité de tête dudit train de tubes de forage (10).
  23. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 22, caractérisé en outre en ce que l'on choisit ledit tronçon tubulaire de tête (10A) de façon telle qu'il ait un diamètre plus petit que le diamètre d'au moins une majorité des tronçons tubulaires restants qui composent ledit train de tubes de forage (10).
  24. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 23, caractérisé en outre en ce que l'on enlève et ledit tronçon tubulaire de tête (10A) de petit diamètre et ledit trépan de forage attaché à celui-ci, dudit train de tubes de forage (10) avant d'attacher ledit trépan aléseur (48) audit train de tubes de forage.
  25. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 22, caractérisé en outre en ce que l'on prévoit au moins un tronçon tubulaire de tête (10A) en une matière flexible à haute résistance et avec un diamètre d'au moins environ 7,6 cm (3 pouces).
  26. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 25, caractérisé en outre en ce que l'on choisit un tronçon tubulaire de tête (10A), qui constituent la terminaison du train de tubes de forage, capable de porter un équipement d'instrumentation associé ainsi que d'avoir ledit trépan de forage qui lui est attaché.
  27. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 22, caractérisé en ce que ledit trépan d'attaque (34) présente une buse d'éjection dans la face antérieure du trépan; en ce qu' l'on fait avancer depuis ledit site d'entrée (O) jusqu'audit site de sortie (E) le tronçon tubulaire de tête (10A) du train de tubes de forage (10) portant le trépan d'attaque (34) avec la buse (34D) ménagée dans ladite face frontale antérieure plate (34A) positionnée directement au voisinage de la formation à creuser et à éroder; et en ce que l'on éjecte un fluide de forage par ladite buse (34D) en un jet, avec le centre du jet de fluide de forage éjecté qui est déporté par rapport à l'axe longitudinal du tronçon tubulaire de tête (10A), ledit trépan d'attaque contribuant au guidage du train de tubes de forage (10) le long de la dite trajectoire courbe prédéterminée.
  28. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 27, caractérisé en outre en ce que l'on applique une rotation partielle prédéterminée du tronçon tubulaire de tête (10A) et du trépan d'attaque (34), changeant ainsi le sens du déport de ladite buse (34D) et la déviation du tronçon tubulaire de tête (10A).
  29. Procédé pour forer un trou pilote souterrain courbe suivant la revendication 27, caractérisé en outre en ce que l'on éjecte ledit fluide de forage hors de ladite buse (34D) en un jet parallèle à mais déporté par rapport à l'axe longitudinal dudit tronçon tubulaire de tête (10A).
EP86303324A 1985-05-14 1986-05-01 Dispositif et procédé d'exécution d'un forage courbe et d'installation d'une conduite dans ce forage Expired - Lifetime EP0209217B1 (fr)

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US73372385A 1985-05-14 1985-05-14
US733723 1985-05-14

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EP0209217A2 EP0209217A2 (fr) 1987-01-21
EP0209217A3 EP0209217A3 (en) 1987-07-01
EP0209217B1 true EP0209217B1 (fr) 1991-07-24

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DE3680402D1 (de) 1991-08-29
EP0209217A2 (fr) 1987-01-21
EP0209217A3 (en) 1987-07-01

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