Abstract: A subsea mudlift pump includes a pressure sealed housing disposed in a body of water in which a wellbore is being drilled by a drilling rig disposed above the surface of the body of water. A motor (44) is configured to generate linear motion is coupled to at least one piston (46) disposed within the housing such that operation of the motor causes linear motion of the piston within the housing. One side of the piston is within a pumped fluid chamber that changes volume when the piston is moved within the housing.

Abstract: An impeller for a centrifugal pump for pumping fluid containing solid particles includes: a rear side wall; a front side wall; a plurality of vanes located between the rear side wall and the front side wall, each vane having an outer edge and a vane width in an axial direction of the impeller. At least one of a periphery of the rear side wall or a periphery of the front side wall projects by a radial distance beyond the outer edges of the vanes, the radial distance being at least 0.5 times the vane width.

Abstract: There is provided a device and method for control of return flow from a borehole (18) where drill fluid is supplied from a surface rig (16) via a multi section drill string (4) to a bottom hole assembly (18), the drill pipe sections (6) having tool joints (8) that include an enlarged outer diameter portion (9), and where an annulus (12) is formed between a pipe (2) and the drill string (4), and where the annulus (12) is in fluid communication with or forms part of a return path (40) for the drill fluid, and where a choke (1) is positioned in the annulus (12), and where the length (L) of the choke (1) exceeds the distance (M) between the enlarged outer diameter portion (9) of two adjacent tool joints (8).

Abstract: Boost system and method for dual gradient drilling where a marine riser (1) has a mud return line (14) connected at a first connection position (18) below the lowest foreseeable mud level (12) in the marine riser (1), and where a mud return pump (16) is connected to the mud return line (14), and where a recirculation line (20) that has a recirculation pump (22), is connected to the marine riser (1) at a second connection position (24) below the lowest foreseeable mud level (12) in the marine riser (1), and at a third connection position (26) on the marine riser (1) below said second connection position (24).

Abstract: A method and a device for enabling the use of riserless drilling fluid recovery from a seabed-based borehole (1) which is to be drilled by means of a casing (26), the casing (26) being provided with a drill bit (28) at its lower portion and with an inner wellhead (30) at its upper portion, and there being a conductor casing (6), which has an outer wellhead (8), in the seabed (2), the method including: —providing a suction module (12) with a dividable adapter (16) which fits complementarily in the outer wellhead (8); —drilling a length of the borehole (1) by means of the casing (26) extending through the suction module (12), while, at the same time, drilling fluid is flowing via the suction module (12) from the borehole (1); —subsequently pulling the adapter (16) up from the outer wellhead (8) and dividing the adapter (16); and—lowering the casing (26) with the inner wellhead (30) through the suction module (12) and the adapter (16) to its position in the outer wellhead (8).

Abstract: A method and device for establishing a borehole (26) in the seabed (4), comprising setting of a conductor (1), wherein the method is characterized in that it comprises:—providing the conductor (1) with a suction module (6);—then lowering the conductor (1) down to the seabed (4); and—displacing the conductor (1) down into the seabed (4).

Abstract: Boost system and method for dual gradient drilling where a marine riser (1) has a mud return line (14) connected at a first connection position (18) below the lowest foreseeable mud level (12) in the marine riser (1), and where a mud return pump (16) is connected to the mud return line (14), and where a recirculation line (20) that has a recirculation pump (22), is connected to the marine riser (1) at a second connection position (24) below the lowest foreseeable mud level (12) in the marine riser (1), and at a third connection position (26) on the marine riser (1) below said second connection position (24).

Abstract: A method and a device for enabling the use of riserless drilling fluid recovery from a seabed-based borehole (1) which is to be drilled by means of a casing (26), the casing (26) being provided with a drill bit (28) at its lower portion and with an inner wellhead (30) at its upper portion, and there being a conductor casing (6), which has an outer wellhead (8), in the seabed (2), the method including:—providing a suction module (12) with a dividable adapter (16) which fits complementarily in the outer wellhead (8);—drilling a length of the borehole (1) by means of the casing (26) extending through the suction module (12), while, at the same time, drilling fluid is flowing via the suction module (12) from the borehole (1);—subsequently pulling the adapter (16) up from the outer wellhead (8) and dividing the adapter (16); and—lowering the casing (26) with the inner wellhead (30) through the suction module (12) and the adapter (16) to its position in the outer wellhead (8).

Abstract: A subsea mudlift pump includes a pressure sealed housing disposed in a body of water in which a wellbore is being drilled by a drilling rig disposed above the surface of the body of water. A motor (44) is configured to generate linear motion is coupled to at least one piston (46) disposed within the housing such that operation of the motor causes linear motion of the piston within the housing. One side of the piston is within a pumped fluid chamber that changes volume when the piston is moved within the housing.

Abstract: An outer rotor of a progressive cavity pump includes at least one inner helical rotor with Z external thread starts and at least one adapted outer rotor with a helical cavity with Z+1 internal thread starts. The at least one outer rotor is assembled from several concentric rotor inserts axially following closely one after another, with helical cavities and Z+1 internal thread starts. Each rotor insert is closely surrounded by and concentrically fixed in a common rigid rotor sleeve. There is detachably connected to the rotor sleeve at least one removable end piece with a principally concentric hollow axially extending through it. The through hollow of the end piece or end pieces forms a gradual transition between a principally circular cross section furthest out and a cross section adapted to the helical cavities of the rotor inserts nearest to them.

Abstract: A particle collector for a dynamic cyclone placed on the ocean bottom for separation of particles in a fluid is described, where the dynamic cyclone comprises a tank (2) which is equipped with an upper inlet opening (25) and an upper and lower outlet opening (26, 32) for outflow of fluid and particles, respectively. Furthermore, the tank comprises a shaft (5) which is equipped with a number of vanes or blades (6) and which is arranged to be driven by an adjoining motor (1), where a centrally placed piece of pipe (4) with a number of slits is arranged around the shaft (5).

Abstract: A progressing cavity pump adapted for pumping of compressible fluids may include an inner rotor having a number of thread-starts together with an adapted stator or outer rotor provided with one extra thread-start. A number of closed pump cavities are formed which are moved, during fluid conveyance, from the inlet side of the pump to the outlet side of the pump, at which position they become open outlet cavities exposed to the fluid pressure in a downstream pipeline. At least one passage is disposed between the outlet side and the closed pump cavity defined closest to the outlet side. The passage is structured for intentional fluid back-flow from the outlet side in a measured and approximately constant volume.

Abstract: A progressive cavity pump includes at least one inner rotor with Z external threads and at least one outer rotor with Z+1 internal threads. The outer rotor has radial bearings at both ends, whereas the inner rotor has a radial bearing only on one side, preferably the inlet side. There is arranged, on the same side as the bearing of the inner rotor, a conventional gear, for example a wheel gear, for maintaining a stable ratio between the rotational speeds of the inner and outer rotors exactly equal to (Z+1)/Z.

Abstract: A progressing cavity pump comprises at least an inner pump rotor enclosed by at least an outer pump rotor so as to collectively form one or more, in principle, separate pump cavities which, according to known geometric principles, will be moved axially through the pump upon bringing the rotors into coordinated rotation. At least two pump sections are disposed therein, each of which comprises one outer pump rotor and one adapted inner pump rotor. The outer pump rotors of all pump sections are fixedly supported and arranged along the same axis, wherein all the inner rotors are supported in fixed positions relative to a pump casing of the pump. The outer rotors of all pump sections are driven by the same motor via at least one differential arranged to allow each pump section to rotate at a mutually different rotational speed.

Abstract: The invention relates to a centralization and running tool (CTR) in a subsea installation in connection with offshore related oil and gas exploration, where the subsea installation (SCM) is arranged to be placed on the ocean bottom or a drilling template and comprises a pipe-formed body (10), at least partially open at the top and extended, arranged to receive and carry through a drill stem (12) from a drilling rig or a drilling vessel. The centralization and running tool (20) is arranged to surround the drill stem (12) and to be placed in the pipe-formed body (10), and the centralization and running tool (20) comprises, together with the drill stem (12), a rotary packing housing (22) with a number of seals (24,26) that lie against the drill stem (12), and the packing housing (22), in accordance with the movements of the drill stem (12), is arranged for radial movement to take up angular deviations of the drill stem (12).

Abstract: A method for the pressure regulation of a well (1) extending into a well formation (2) and being drilled from a drilling vessel at sea, the well (1) including a blowout preventer (10) on the seabed (12) and a riser (14) extending from the blowout preventer (10) up to the vessel, and the return path (8, 14, 20) of a drilling fluid (24) being provided with a rotatable surface seal (22) sealingly surrounding a drill string (4), the rotatable surface seal (22) being arranged to seal against a pressure difference between the surroundings and the return path (8, 14, 20), and there being arranged, at the rotating surface seal (22), a closable drilling-fluid outlet (28), the method including: arranging a pump inlet (32) from the return path (8, 14, 20) under water; connecting a pump (30) to the return path (8, 14, 20), the pump (30) being connected to a pressure pipe (34) discharging on the vessel; monitoring the drilling-fluid pressure; and controlling the pumping rate through the pump (30) to maintain a substantial

Abstract: An outer rotor of a progressive cavity pump comprising at least one inner helical rotor with Z external thread starts and at least one adapted outer rotor with a helical cavity with Z+1 internal thread starts, characterized in that at least an outer rotor (1, 3) is assembled from several concentric rotor inserts (109-113, 307-311) following closely one after another axially, with helical cavities and Z+1 internal thread starts, each rotor insert being closely surrounded by and concentrically fixed in a common rigid rotor sleeve (101, 301), and there being detachably connected to the rotor sleeve at least one removable end piece (102, 302, 303) with a principally concentric hollow extending through it axially, and that the through hollow of the end piece (102) or end pieces (302, 303) forms a gradual transition (106, 306, 312) between a principally circular cross section furthest out (135, 313, 314) and a cross section adapted to the helical cavities of the rotor inserts nearest to them (109, 307, 311).

Abstract: The invention relates to a progressive cavity pump comprising at least one inner rotor (18) with Z external threads and at least one adapted outer rotor with Z+1 internal threads, characterized by the outer rotor having radial bearings at both ends, whereas the inner rotor has a radial bearing (11) only on one side, preferably the inlet side, and there being arranged, on the same side as the bearing of the inner rotor, a conventional gear, for example a wheel gear (33 etc.), maintaining a stable ratio between the rotational speeds of the inner and outer rotors exactly equal to (Z+1)/Z.

Abstract: A system and method is described for use and return of drilling fluid/cuttings from a well, which is drilled on the ocean floor, in connection with offshore related oil production and gas production, where, from a drilling rig or drilling vessel (10), a drill stem (12) runs down into the bore hole and where a blowout preventer (BOP) is placed on said well, without mounting a riser between the rig or the vessel and said blowout preventer. A sealing and pressure-regulating device (16) is arranged on the blowout preventer (14) arranged to regulate the level of the drilling fluid, and thus the outlet pressure of the drilling fluid in said sealing and pressure-regulating device, and a pump module (18) is set up at a suitable distance adjacent said sealing and pressure-regulating device, where the pump module is arranged to pump said drilling fluid up to the ocean surface via an external return pipe.

Abstract: A progressing cavity pump comprises at least an inner pump rotor enclosed by at least an outer pump rotor so as to collectively form one or more, in principle, separate pump cavities which, according to known geometric principles, will be moved axially through the pump upon bringing the rotors into coordinated rotation. At least two pump sections are disposed therein, each of which comprises one outer pump rotor and one adapted inner pump rotor. The outer pump rotors of all pump sections are fixedly supported and arranged along the same axis, wherein all the inner rotors are supported in fixed positions relative to a pump casing of the pump. The outer rotors of all pump sections are driven by the same motor via at least one differential arranged to allow each pump section to rotate at a mutually different rotational speed.