|
(11) | EP 3 494 282 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
|
|
| (54) |
COILED TUBING ARRANGEMENT FOR WELLBORE UNLOADING GEWICKELTE ROHRLEITUNGSANORDNUNG ZUR BOHRLOCHENTLASTUNG DISPOSITIF DE TUBAGE ENROULÉ POUR LE DÉCHARGEMENT DE PUITS DE FORAGE |
|
|
||||||||||||||||||||||||||||
| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
1. Field of the Invention
2. Description of the Related Art
[0002] In the course of production of hydrocarbon production fluids from a wellbore, it is often necessary to unload, or clean, the wellbore by removing solids and liquids from the wellbore. Typically, removal of such solids and liquids is needed following stimulation. Baker Hughes has used a Sand VacTM and Well VacTM system which features a high pressure fluid jet pump for dislodging debris coupled with a debris vacuum for transporting debris solids and liquids to surface.
[0003] From EP 852 571 A1 an apparatus for borehole cleaning is known The apparatus comprises a tubular conveyance for extending from the surface into a borehole to a region to be cleaned, a motor mounted at the end of the tubular conveyance that in use is introduced into the borehole and a pump connected to the motor and having a nozzle. The pump is arranged such that, when positioned in the borehole and operated by the motor, the pump withdraws material from the borehole through the nozzle and pumps it into the tubular conveyance to the surface.
SUMMARY OF THE INVENTION
[0004] The present invention provides an arrangement and method for unloading wellbores using a high pressure fluid jet pump and debris vacuum in conjunction with nitrogen injection. The wellbore unloading arrangement includes a running string and an unloading bottom hole assembly, wherein the running string is configured to dispose the unloading bottom hole assembly into the wellbore, and wherein the unloading bottom hole assembly is carried by the running string. The unloading bottom hole assembly is configured to inject nitrogen and a liquid into the wellbore, and the unloading bottom hole assembly is further configured to draw debris into the running string using suction. The unloading bottom hole assembly incorporates a jet pump which is operable to inject the liquid through nozzles into the wellbore and subsequently to provide suction power to draw debris through vacuum ports into a flowbore of the running string. The running string may be made up of two strings of inner coiled tubing which are disposed within an outer coiled tubing string.
[0005] The unloading bottom hole assembly is affixed to the running string and further incorporates a nitrogen injection tool. Nitrogen injection during operation of the fluid jet pump decreases the density of fluids within the wellbore proximate the bottom hole assembly, thereby improving the effectiveness of the debris vacuum. The inventors have also determined that the combination of fluid jetting, vacuum and nitrogen injection allows a user to unload wellbores, at greater depths than with conventional techniques. Nitrogen injection counteracts hydrostatic pressure that could otherwise preclude the removal of debris.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein:
Figure 1 is a side, cross-sectional view of an exemplary wellbore which contains a wellbore unloading arrangement constructed in accordance with the present disclosure
Figure 2 is an axial cross-section of the running string of the wellbore unloading arrangement.
Figure 3 is a side view of an exemplary unloading bottom hole assembly in accordance with the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] Figure 1 illustrates an exemplary wellbore 10 which has been drilled through the earth 12 from the surface 14 down to a hydrocarbon-bearing formation 16. Debris 18 is located within the wellbore 10. The debris 18 is typically relatively fine and may include sand and cuttings.
[0008] A wellbore unloading arrangement 20 is disposed within the wellbore 10 from the surface 14 via a coiled tubing injector (not shown). The wellbore unloading arrangement 20 includes a running string 22 and an unloading bottom hole assembly 24.
[0009] Figure 2 depicts an axial cross-section of the running string 22. It can be seen that the running string 22 includes an outer coiled tubing string 26 which defines a flowbore 28. First and second inner coiled tubing strings 30, 32 are located within the flowbore 28 of the outer coiled tubing string 26.
[0010] Figure 3 illustrates an exemplary unloading bottom hole assembly 24 in greater detail. The unloading bottom hole assembly 24 includes an outer housing 34 with a nose portion 36 having injection nozzles 38 for injection of fluids into the wellbore 10. The fluids that can be injected via the injection nozzles 38 are provided via the first and second coiled tubing strings 30, 32. In a preferred embodiment, the lower end of the first coiled tubing string 30 is blocked by a plug 39 to cause fluid flowing through the first coiled tubing string 30 to exit through a lateral opening 41. Vacuum ports 40 are located in the housing 34 to permit fluid and solids to enter the flowbore 28 of the outer coiled tubing string 26 from the wellbore 10. Debris 18 will enter the flowbore 28 of the outer coiled tubing string 26 and then to surface 14. Larger debris 18 may be filtered out from entering the flowbore 28 by screening by the vacuum ports 40.
[0011] A nitrogen supply 42 and associated fluid pump 44 are located at surface 14 and are operably associated with the wellbore unloading arrangement 20 to flow nitrogen into the first inner coiled tubing string 30. A liquid supply 46 and associated fluid pump 48 are also located at surface 14 and are operably associated with the wellbore unloading arrangement 20 to flow liquid from the liquid supply 46 into the second inner coiled tubing string 32. The liquid of the liquid supply 46 is typically water but may be other fluids as well. A coiled tubing injection assembly (not shown), of a type well known in the art, is also located at surface 14 and is used to inject the wellbore unloading arrangement 20 into the wellbore 10 as well as remove it from the wellbore 10.
[0012] In operation, the wellbore unloading arrangement 20 is disposed into the wellbore 10 and lowered so that the unloading bottom hole assembly 24 is in a desired location proximate the debris 18 to be removed. Nitrogen is pumped through the first inner coiled tubing string 30 to the unloading bottom hole assembly 24. Non-nitrogen liquid is pumped down the second inner coiled tubing string 32 to the unloading bottom hole assembly 24. During operation, a fluid jet pump 33 switches between injection of liquid from the second inner coiled tubing string 32 through nozzles 38 and vacuum power to draw debris into the flowbore 28 of the outer coiled tubing string 26 through vacuum ports 40. The liquid that is injected through injection nozzles 38 will help dislodge debris 18 within the wellbore 10. This dislodged debris 18 can then be drawn into the flowbore 28 through vacuum ports 40.
[0013] During operation to remove the debris 18, nitrogen can be flowed from the nitrogen source 42 to injection nozzles 38. Nitrogen injection into the wellbore 10 will preferably occur proximate the debris 18 and may be done continuously as injection of liquid and vacuuming occurs. Also, the wellbore unloading arrangement 20 may be moved axially within the wellbore 10 during these operations to help further dislodge debris 18 and aid its removal.
[0014] The inventors believe that nitrogen injection during operation of the fluid jet pump 33 decreases the density of fluids within the wellbore 10 proximate the unloading bottom hole assembly 24, thereby improving the effectiveness of the debris vacuum. Further, the inventors have discovered that effective operation of the liquid injection and debris removal is possible at greater wellbore depths than with conventional systems.
a running string (22) and an unloading bottom hole assembly (24),
wherein the running string (22) is configured to dispose the unloading bottom hole assembly (24) into the wellbore (10),
and wherein the unloading bottom hole assembly (24) is carried by the running string (22),
characterized in that
the unloading bottom hole assembly (24) is configured to inject nitrogen and a liquid into the wellbore (10), and the unloading bottom hole assembly (24) is further configured to draw debris (18) into the running string (22) using suction; and that
the unloading bottom hole assembly (24) incorporates a jet pump (33) which is operable to inject the liquid through nozzles (38) into the wellbore (10) and subsequently to provide suction power to draw debris through vacuum ports (40) into a flowbore (28) of the running string (22).
an outer coiled tubing string (26) defining the flowbore (28) along its length;
a first inner coiled tubing string (30) within the flowbore (28) of the outer coiled tubing string (26); and
a second inner coiled tubing string (32) within the flowbore (28) of the outer coiled tubing string (26).
the nitrogen is flowed through the first inner coiled tubing string (30); and
the liquid is flowed through the second inner coiled tubing string (32).
disposing a wellbore unloading arrangement (20) into the wellbore (10), the wellbore unloading arrangement (20) having an unloading bottom hole assembly (24);
injecting a liquid into the wellbore (10) through the unloading bottom hole assembly (24) to dislodge the debris (18);
removing the debris (18) from the wellbore (10) by drawing the debris (18) into the unloading bottom hole assembly (24) with suction; and
injecting nitrogen into the wellbore (10) through the unloading bottom hole assembly (24) proximate the debris (18);
wherein a jet pump (33) is provided operable to inject the liquid into the wellbore (10) and to subsequently provide suction to draw debris into the unloading bottom hole assembly (24).
disposing an unloading bottom hole assembly (24) into the wellbore (10) with a running string (22) which includes an outer coiled tubing string (26) which defines a flowbore (28) and at least one inner coiled tubing string (30, 32) which resides within the flowbore (28).
injecting the nitrogen through the at least one inner coiled tubing string (30); and removing the debris (18) through the flowbore (28).
einen Laufstrang (22) und eine Lochbodenentlastungsvorrichtung (24),
wobei der Laufstrang (22) dazu konfiguriert ist, die Lochbodenentlastungsvorrichtung (24) in das Bohrloch (10) einzusetzen,
und wobei die Lochbodenentlastungsvorrichtung (24) von dem Laufstrang (22) geführt wird,
dadurch gekennzeichnet, dass
die Lochbodenentlastungsvorrichtung (24) dazu konfiguriert ist, Stickstoff und eine Flüssigkeit in das Bohrloch (10) einzuspritzen, und die Lochbodenentlastungsvorrichtung (24) ferner dazu konfiguriert ist, Bohrschutt (18) durch Ansaugen in den Laufstrang (22) zu ziehen; und dadurch dass
die Lochbodenentlastungsvorrichtung (24) eine Strahlpumpe (33) enthält, die betreibbar ist, um die Flüssigkeit durch Düsen (38) in das Bohrloch (10) einzuspritzen und anschließend eine Saugleistung bereitzustellen, um Bohrschutt durch Vakuumöffnungen (40) in eine Durchflussbohrung (28) des Laufstrangs (22) zu ziehen.
einen äußeren gewickelten Rohrleitungsstrang (26), der die Durchflussbohrung (28) entlang ihrer Länge definiert;
einen ersten inneren gewickelten Rohrleitungsstrang (30) innerhalb der Durchflussbohrung (28) des äußeren gewickelten Rohrleitungsstrangs (26); und
einen zweiten inneren gewickelten Rohrleitungsstrang (32) innerhalb der Durchflussbohrung (28) des äußeren gewickelten Rohrleitungsstrangs (26).
der Stickstoff durch den ersten inneren gewickelten Rohrleitungsstrang (30) geleitet wird; und
die Flüssigkeit durch den zweiten inneren gewickelten Rohrleitungsstrang (32) geleitet wird.
Einsetzen einer Bohrlochentlastungsanordnung (20) in das Bohrloch (10), wobei die Bohrlochentlastungsanordnung (20) eine Lochbodenentlastungsvorrichtung (24) aufweist;
Einspritzen einer Flüssigkeit in das Bohrloch (10) durch die Lochbodenentlastungsvorrichtung (24), um den Bohrschutt (18) abzulösen;
Entfernen des Bohrschutts (18) aus dem Bohrloch (10) durch Absaugen des Bohrschutts (18) in die Lochbodenentlastungsvorrichtung (24); und
Einspritzen von Stickstoff in das Bohrloch (10) durch die Lochbodenentlastungsvorrichtung (24) in der Nähe des Bohrschutts (18);
wobei eine Strahlpumpe (33) bereitgestellt wird, die betreibbar ist, um die Flüssigkeit in das Bohrloch (10) einzuspritzen und anschließend eine Absaugung bereitzustellen, um Bohrschutt in die Lochbodenentlastungsvorrichtung (24) zu ziehen.
Einsetzen einer Lochbodenentlastungsvorrichtung (24) in das Bohrloch (10) mit einem Laufstrang (22), der einen eine Durchflussbohrung (28) definierenden äußeren gewickelten Rohrleitungsstrang (26) und mindestens einen sich innerhalb der Durchflussbohrung (28) befindlichen inneren gewickelten Rohrleitungsstrang (30, 32) einschließt.
Einspritzen des Stickstoffs durch den mindestens einen inneren gewickelten Rohrleitungsstrang (30); und Entfernen des Bohrschutts (18) durch die Durchflussbohrung (28).
un train de tiges (22) et un ensemble de trou de fond de déchargement (24),
dans lequel le train de tiges (22) est configuré pour disposer l'ensemble de trou de fond de déchargement (24) dans le puits de forage (10),
et dans lequel l'ensemble de trou de fond de déchargement (24) est porté par le train de tiges (22),
caractérisé en ce que
l'ensemble de trou de fond de déchargement (24) est configuré pour injecter de l'azote et un liquide dans le puits de forage (10), et l'ensemble de trou de fond de déchargement (24) est en outre configuré pour aspirer des débris (18) dans le train de tiges (22) par aspiration ; et en ce que
l'ensemble de trou de fond de déchargement (24) incorpore une pompe à jet (33) qui peut être actionnée pour injecter le liquide à travers des buses (38) dans le puits de forage (10) et ensuite pour fournir une puissance d'aspiration pour aspirer des débris à travers des orifices de vide (40) dans un alésage d'écoulement (28) du train de tiges (22).
un train de tubage enroulé externe (26) définissant l'alésage d'écoulement (28) le long de sa longueur ;
un premier train de tubage enroulé interne (30) à l'intérieur de l'alésage d'écoulement (28) du train de tubage enroulé externe (26) ; et
un deuxième train de tubage enroulé interne (32) à l'intérieur de l'alésage d'écoulement (28) du train de tubage enroulé externe (26).
l'azote s'écoule à travers le premier train de tubage enroulé interne (30) ; et
le liquide s'écoule à travers le deuxième train de tubage enroulé interne (32).
disposer un agencement de déchargement de puits de forage (20) dans le puits de forage (10), l'agencement de déchargement de puits de forage (20) ayant un ensemble de trou de fond de déchargement (24) ;
injecter un liquide dans le puits de forage (10) à travers l'ensemble de trou de fond de déchargement (24) pour déloger les débris (18) ;
éliminer les débris (18) du puits de forage (10) en aspirant les débris (18) dans l'ensemble de trou de fond de déchargement (24) par aspiration ; et
injecter de l'azote dans le puits de forage (10) à travers l'ensemble de trou de fond de déchargement (24) à proximité des débris (18) ;
dans lequel une pompe à jet (33) est fournie pour injecter le liquide dans le puits de forage (10) et pour fournir ensuite une aspiration pour aspirer des débris dans l'ensemble de trou de fond de déchargement (24).
la disposition d'un ensemble de trou de fond de déchargement (24) dans le puits de forage (10) avec un train de tiges (22) qui inclut un train de tubage enroulé externe (26) qui définit un alésage d'écoulement (28) et au moins un train de tubage enroulé interne (30, 32) qui se trouve à l'intérieur de l'alésage d'écoulement (28).
l'injection de l'azote à travers l'au moins un train de tubage enroulé interne (30) ; et l'élimination des débris (18) à travers l'alésage d'écoulement (28).
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description