Abstract: A seal assembly for a nested dual drill pipe includes a tube having a female seal assembly and a male seal assembly at the longitudinal ends. The female seal assembly includes a larger internal diameter portion, a taper adjacent thereto and a smaller internal diameter portion adjacent to the taper. The male seal assembly includes a smaller external diameter portion, a seal groove adjacent thereto and a larger external diameter portion adjacent to the seal groove. The smaller internal diameter portion and the larger external diameter portion have diameters selected to enable free longitudinal movement of the male seal assembly into the female seal assembly while limiting axial displacement to maintain the seal ring fully energized.

Abstract: A sealing system between a relatively rotating element and a stationary element has at least three sealing elements arranged between the rotating element and the stationary element and arranged in series between a process fluid and an environment, and a barrier fluid arrangement to provide a barrier fluid to spaces formed between the sealing elements. The barrier fluid arrangement has at least two compensator devices where under use the pressure in the process fluid is acting on one side of a piston in the compensator device and the pressure in the barrier fluid is acting on the opposite side of the piston. There is a difference between cross sectional areas of the two sides of the piston and the difference varies between the at least two compensator devices.

Abstract: The present invention regards a valve device for use with a down hole tool comprising at least a first fluid line and a return fluid line, the valve device comprises a first inlet and a first outlet forming a first flow path between them, and a second inlet and a second outlet forming a second flow path between them, at least one closure element for closing and or opening at least one of the flow paths. According to the invention there is at least one closure element together with the respective flow paths forms a first and second check valves, which in a first state prevents a fluid from flowing from the first outlet to the first inlet and a fluid from flowing from the second inlet to the second outlet. The invention also regards a method for operating a down hole valve device.

Abstract: A method to be used when performing drilling in a well bore and a device for performing the method are disclosed. The method includes positioning in the well bore a drill string comprising at least two pipe conduits, an upper end, and a lower end comprising a drilling tool, thereby forming an outer annulus between the well bore wall and the drill string. A well bore section comprising at least one u-shaped section is drilled. A first fluid with a first density is fed into the outer annulus above the u-shaped section, and a second fluid with a second density is provided within the drill string and around the tool, where the first density is larger than the second density.

Abstract: The invention concerns a unit for a down hole well tool comprising a tool unit comprising at least one first fluid conduit and a return fluid conduit in use forming a well annulus space between the tool unit and the well bore. The tool unit is arranged with at least one piston provided for dividing the well annulus space into at least two well annulus spaces. The communication of fluid between the adjacent well annulus spaces at each side of the piston is controlled by the relative movement between the first fluid conduit and a control element.

Abstract: The present invention regards a method for performing core sampling during drilling of wells, comprising the steps of providing a dual bore drill pipe with drill bit in the end in the well bore, providing means to introduce a drill liquid into an annular space of the drill pipe and return it together with drill cuttings to the surface through centrally arranged return line in the dual bore drill pipe, removing larger cuttings at outlet of return pipe, and perform core testing on these cuttings, knowing where the cuttings come from in the well. The invention also regards a device for performing the invention.

Abstract: The present invention regards a method to be used when performing drilling in a well bore, comprising: positioning a dual bore drill pipe with a tool at on one end into a well bore, thereby forming an outer annulus between the well bore wall and the pipe and two inner bores within the pipe, dividing the outer annulus into two different sections along the longitudinal axis of the drill pipe, at least at one location close to the tool, providing a first fluid in the outer annuls and providing a second fluid within the drill pipe and around the tool, and a device.

Abstract: The present invention relates to a method for cleaning and possibly sealing a subsurface well. According to the method a multichannel tool string comprising an adapter on a first end of the tool string, a guide device at the second end of the tool string are run into the well, whereupon the guide device is activated in order to permit the well to be flushed by the supply of fluid through at least one of the channels in connection with the tool string and fluids and particles from the well are transported back to the surface through at least one other of the channels in connection with the tool string. The invention also relates to a device for cleaning and possibly sealing a subsurface well.

Abstract: The present invention relates to a system for transferring signals through a drill pipe system during drilling of a subsurface well. The drill pipe system comprises a first pipe (1) provided concentric inside a second pipe (2) by means of hanging devices (3, 3a). The first pipe (1) is electrically insulated from the second pipe (2). A first signal transceiver is electrically connected to the top of the drill pipe system. A second signal transceiver is electrically connected along or in the bottom of the drill pipe system. The first and second signal transceivers are electrically connected to the first and second pipes (1, 2) for transferring the signals through the drill pipe system.

Abstract: The present invention regards a sealing arrangement for a valve, comprising a valve element (3) provided with a sealing element (4), arranged to be abutting a valve seat (2) in a closed state of the valve. The valve element (3) comprises at least two parts, a first and second part (31,32), each comprising an abutting surface (310,320), which abutting surfaces (310,320) are arranged facing each other and to abut against corresponding sealing element surfaces (41,42) of the sealing element (4), and whereof at least one part (31) of the valve element (3) is being arranged to be moveable relative another part (32) of the valve element (3) and the at least one part (31) of the valve element (3) comprises a pressure surface (311) exposed to a surrounding fluid in a closed state of the valve giving pressure on the sealing element (4) responsive to the pressure in the surrounding fluid.

Abstract: A down hole well tool (3) for installing a casing or liner (1) in a well bore, wherein the down hole well tool comprises a tool unit comprising at least one first fluid conduit (4) and a return fluid conduit (15) in use forming an annulus between the tool unit and the casing or liner (1). The tool unit further comprises at least one piston (5) in the annulus dividing the annulus into annulus spaces, wherein an expansion module for the expansion of the casing or liner is provided in the annulus. The expansion module has at least two sets of rolling means (9a, 9b, 9c) arranged along the axial direction of the expansion module. Each set of rolling means is provided at an outer circumference of the expansion module and the diameter of the rolling means decreases along the expansion module in the axial down hole direction of the well bore providing the expansion module with an decreasing diameter.

Abstract: A down hole well tool (1) comprising a tool unit comprising at least one first fluid conduit (2) and a return fluid conduit (3) in use forming a well annulus between the tool unit and a well bore, and at least one piston (4) dividing the well annulus into well annulus spaces. The piston comprises at least two piston bodies wherein a first piston body (4a) is arranged to rotate with the tool unit and a second piston body (4b) is arranged in a position in between the first piston body and the well bore. The first piston body is arranged to rotate relative the second piston body and first sealing means are arranged in between the first piston body and the second piston body.

Abstract: A down hole well tool (3) for installing a casing/liner (1) in a well bore (2), wherein the down hole well tool comprises a tool unit comprising at least one first fluid conduit (6) and a return fluid conduit (5) in use forming an annulus between the tool unit and the casing/liner. The tool unit further comprises at least one piston (7a, 7b) in the annulus dividing the annulus into annulus spaces (8a, 8b, 8c). At least two expansion modules (9a, 9b) for the expansion of the casing are positioned displaced in the axial direction of the casing. The expansion modules are arranged to be moved relative to each other in the axial direction of the casing.

Abstract: A method and device for a running tool for drilling or cleaning and setting a lining and a completion string in an underground borehole. The running tool comprising a drilling tool, an expandable casing, an expansion tool, a packer arranged to seal against the wall of the casing, and at least one conduit extending up to the surface. The drilling tool is releasably connected to the lower portion of the expanding casing, and the expansion tool and the packer are releasably connected to the upper portion of the expanding casing. The running tool is arranged to communicate with the surface through at least one pipe conduit.

Abstract: A sealing system between a relatively rotating element and a stationary element has at least three sealing elements arranged between the rotating element and the stationary element and arranged in series between a process fluid and an environment, and a barrier fluid arrangement to provide a barrier fluid to spaces formed between the sealing elements. The barrier fluid arrangement has at least two compensator devices where under use the pressure in the process fluid is acting on one side of a piston in the compensator device and the pressure in the barrier fluid is acting on the opposite side of the piston. There is a difference between cross sectional areas of the two sides of the piston and the difference varies between the at least two compensator devices.

Abstract: The invention concerns a unit for a down hole well tool comprising a tool unit comprising at least one first fluid conduit and a return fluid conduit in use forming a well annulus space between the tool unit and the well bore. The tool unit is arranged with at least one piston provided for dividing the well annulus space into at least two well annulus spaces. The communication of fluid between the adjacent well annulus spaces at each side of the piston is controlled by the relative movement between the first fluid conduit and a control element.

Abstract: The present invention regards a valve device for use with a down hole tool comprising at least a first fluid line and a return fluid line, the valve device comprises a first inlet and a first outlet forming a first flow path between them, and a second inlet and a second outlet forming a second flow path between them, at least one closure element for closing and or opening at least one of the flow paths. According to the invention there is at least one closure element together with the respective flow paths forms a first and second check valves, which in a first state prevents a fluid from flowing from the first outlet to the first inlet and a fluid from flowing from the second inlet to the second outlet. The invention also regards a method for operating a down hole valve device.

Abstract: A method and a device for establishing an underground borehole (10) and setting a casing (6) in the borehole (10), wherein the running tool (1) including a drilling tool (14), an expandable casing (6), an expansion tool (32) and a packer (30) which is arranged to seal against the wall of the borehole (10), is placed at the bottom of the borehole (10), whereupon the borehole (10) is drilled to the necessary length in order then to set the expandable casing (6), and in subsequent operations the casing is reinforced and a completion string is run, having built-in cables for downhole control and monitoring.

Abstract: The present invention relates to a method for cleaning and possibly sealing a subsurface well. According to the method a multichannel tool string comprising an adapter on a first end of the tool string, a guide device at the second end of the tool string are run into the well, whereupon the guide device is activated in order to permit the well to be flushed by the supply of fluid through at least one of the channels in connection with the tool string and fluids and particles from the well are transported back to the surface through at least one other of the channels in connection with the tool string. The invention also relates to a device for cleaning and possibly sealing a subsurface well.

Abstract: A method and a device for establishing an underground borehole (10) and setting a casing (6) in the borehole (10), wherein the running tool (1) including a drilling tool (14), an expandable casing (6), an expansion tool (32) and a packer (30) which is arranged to seal against the wall of the borehole (10), is placed at the bottom of the borehole (10), whereupon the borehole (10) is drilled to the necessary length in order then to set the expandable casing (6), and in subsequent operations the casing is reinforced and a completion string is run, having built-in cables for downhole control and monitoring.