Abstract: A pipe segment having an insulated electrical conductor includes a first electrical contact disposed at one end of an electrical conductor on an interior of the pipe segment from a male threaded connection on one end to a female threaded connection on the other end of the pipe segment. A second electrical contact is on the other end of the insulated electrical conductor. The first contact makes electrical connection with the second contact in an adjacent segment when the male connection on one segment is engaged to the female connection on the adjacent segment. A seal disposed on an interior of an insulating layer on an interior wall of each respective pipe segment provides a space beyond the end of the seal to enable inward flexure of the seal under pressure such that lubricant extruded by connecting the male threaded end and the female threaded end is pressure relieved.

Abstract: A method for making a wired drill pipe joint includes forming an electrically conductive material into a structure that is radially expandable to conform to an interior of the pipe joint substantially without plastic deformation of the electrically conductive material. An electrical connector is coupled to each longitudinal end of the formed electrically conductive material to form an electrical conductor assembly. An interior of the pipe joint is coated with an electrically insulating material. The electrical conductor assembly is inserted into the pipe joint. The electrically conductive material is radially expanded to conform to an interior surface of the pipe joint wherein a bonding material is applied to the interior wall of the pipe joint.

Abstract: A casing drilling system includes combination conduit of a casing and a pipe inside the casing. A first adapter has a flow diverter to redirect at least flow of drilling fluid returning from a bottom of a wellbore to either an interior of the pipe or an annular space between the casing and the pipe. A second adapter has a flow diverter to redirect flow of drilling fluid into the conduit through the other one of the interior of the pipe and the annular space. The second adapter has a fluid connection between either the interior of the pipe or the annular space and a rotationally fixed fluid outlet. The system includes a casing chuck having means to support the casing and a slidable conduit operable to expose an uppermost end of the casing and a connection between the second adapter and an uppermost end of the pipe.

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: A method for inserting a conduit into a wellbore includes inserting the conduit into the wellbore until an upper end of a predetermined section thereof is disposed proximate a selected position in the wellbore and reducing pressure in the conduit to a predetermined pressure.

Abstract: A dual drill string actuator includes a piston disposed in a housing. The housing is configured to sealingly couple at its longitudinal ends to an end of a nested dual drill string segment. An upper internal conduit is mounted in the housing proximate one longitudinal end thereof. A lower internal conduit is mounted in the housing proximate the other longitudinal end thereof. The piston is slidably, sealingly engaged between the upper and lower inner conduits and together define an internal fluid flow passage therethrough. The upper inner conduit, the piston and the lower inner conduit also define an external flow passage between respective exterior surfaces thereof and an interior of the housing such that application of fluid pressure to the external flow passage causes movement of the piston.

Abstract: A method to be used when performing drilling in a well bore involves positioning a dual bore drill pipe in a well bore. An outer annulus formed between the drill pipe and well bore wall is divided into two different sections. A first fluid is provided in one of the sections. A second fluid having a density less than the first fluid is circulated into and out of the well bore through the drill pipe. The densities of the first and second fluids are such that the drill pipe is at least partly floating in the first fluid in the outer annulus.

Abstract: A casing drilling system includes combination conduit of a casing and a pipe inside the casing. A first adapter has a flow diverter to redirect at least flow of drilling fluid returning from a bottom of a wellbore to either an interior of the pipe or an annular space between the casing and the pipe. A second adapter has a flow diverter to redirect flow of drilling fluid into the conduit through the other one of the interior of the pipe and the annular space. The second adapter has a fluid connection between either the interior of the pipe or the annular space and a rotationally fixed fluid outlet. The system includes a casing chuck having means to support the casing and a slidable conduit operable to expose an uppermost end of the casing and a connection between the second adapter and an uppermost end of the pipe.

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 method for inserting a conduit into a wellbore includes inserting the conduit into the wellbore until an upper end of a predetermined section thereof is disposed proximate a selected position in the wellbore and reducing pressure in the conduit to a predetermined pressure.

Abstract: A method and device for drilling or cleaning an underground borehole. The device includes a drilling tool, a drill string with two pipe conduits extending up to the surface and an arrangement for providing one drilling fluid for circulation in a drill string and a second arrangement for providing a second fluid in an annulus formed between the drill string and the wall of a borehole making the drill string approximately weightless.

Abstract: A method for operating a dual drill string disposed in a wellbore, the string having a shutoff valve for at least a fluid return drill string therein proximate a bottom end thereof includes pumping fluid into the fluid return string such that a pressure therein is substantially equal to a fluid pressure in the wellbore. Circulation of fluid in the wellbore is initiated by pumping fluid into a fluid supply string of the dual drill string such that the shutoff valve on the fluid return string opens to enable the fluid leaving the wellbore to enter the fluid return string.

Abstract: A dual drill string valve includes an actuator including a piston disposed in a housing. The housing is configured to couple at its ends to an end of a nested dual drill string segment. An upper internal conduit is mounted in the housing proximate one longitudinal end thereof. A lower internal conduit is mounted in the housing proximate the other longitudinal end thereof. The piston is slidably, sealingly engaged between the upper and lower inner conduits and defines a fluid flow passage therethrough. The upper inner conduit, the piston and the lower inner conduit define another flow passage between respective exterior surfaces thereof and an interior of the housing such that application of fluid pressure to the external flow passage causes movement of the piston away from the upper inner conduit. A rotary valve is coupled to the actuator whereby longitudinal movement thereof rotates the rotary valve.

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 mud lift pump for a dual drill string includes an energy input and an energy output in fluid communication with a fluid return flow passage in the dual drill string.

Abstract: A down hole well tool for installing a casing or liner in a well bore includes a tool unit and an expansion module for expansion of the casing or liner. The expansion module has at least two sets of rolling means arranged along an axial direction of the expansion module, and each set of rolling means is provided at an outer circumference of the expansion module. The diameter of the rolling means decreases at least between the two sets along the expansion module, providing the expansion module with a decreasing diameter in an axial down hole direction of the well bore.

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: 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: A dual drill pipe joint includes a pin end and a box end. An inner pipe is disposed within an internal bore of the joint of drill pipe. A retainer is disposed proximate each longitudinal end of the inner pipe. A retaining feature is formed in an interior of the joint of drill pipe proximate each longitudinal end. The features are configured to engage a respective one of the retainers so that the inner pipe is held in longitudinally fixed relation to the joint of drill pipe.

Abstract: A drilling method includes arranging a dual drill string (20) having an inlet fluid conduit (9) and a return fluid conduit (10) in a well (14) formed in a subsurface formation such that a well annulus (22) is formed between the dual drill string (20) and a wall (21) of the well (14). A divider element (3) is disposed in the well annulus (22) to divide the well annulus (22) into an upper annular region (5) extending above the divider element (3) to a surface of the well annulus (22) and a lower annular region (12) extending below the divider element (3) towards a bottom of the well annulus (22). The lower annular region (12) contains a first fluid (25). A second fluid (27) is fed into the upper annular region (5). The method includes configuring the second fluid such that the density of the second fluid (27) is greater than the density of the first fluid (25).