Abstract: The invention concerns a method for casing a borehole which consists of successively lowering an unlimited plurality of strings of casing having a common diameter, the next one through the preceding one, to be installed one beneath the other and being sealingly connected. Thus a next casing (6) is lowered folded through the preceding casing (5) and the expansion process consists either in injecting pressurized fluid through the drillstring (54) towards the next casing (6) so as to re-inflate it, or the next casing (6) is a cylindrical pipe having a diameter smaller than the internal diameter of the preceding casing (5) and the expansion process consists in forcing a cylindrical gauge (52) from the top end (26) to the bottom bell (28) of the next casing (6) so as to increase its diameter to make it equal to the diameter of the preceding casing (5). The method can use a cementing shoe (34) and a metal-to-metal seal (29) between the casing string.

Abstract: Pipe-in-pipe composite tubular structure having between layers a hardenable filling material associating the layers to enhance the structure mechanical performance mostly in collapse. Prior to harden the filling material, the composite tubular structure can be longitudinally deployable between a folded configuration and a deployed configuration, and has a radial dimension increasing between the folded configuration and the deployed configuration. Such structure is well fitted to be used in oil-well downhole structure and casings or underwater pipeline/flowline.

Abstract: A multi-structure pipe intended to transport a fluid, used in particular in oil production, including a first hollow and closed tubular structure having a set of substantially circumferential slits, each slit extending on an arc of more than 180° and defining a tension band extending with a helix shape along the said first tubular structure, and at least a second tubular structure having also at least a tension band also in helix shape of the same direction and pitch as the first tubular structure, and the tension bands of the first and second tubular structure being maintained at a fix distance from one another by support of the second tension band on the first tubular structure to provide the tension capacity of the pipe.

Abstract: A preloaded connector to connect sealingly two pipe segments having a common axis, comprising at least one couple of cooperating pin and box members, the members including load-bearing surfaces to transmit tension and compression axial forces, the connector comprising means to apply, after engagement of the members, a sufficient axial force on at least one of the members, to modify in the plastic range the axial length of at least a portion of said members, so that after release of the axial force a preload subsists on the load-bearing surfaces.

Abstract: A method to install a cylindrical pipe in a wellbore through a previously installed casing forming a reduced opening by running a pipe within the casing, the pipe having a first shape having dimensions smaller than the dimensions of the reduced opening; then deforming the pipe to convert the pipe from the first shape to a substantially cylindrical second shape in a cavity having larger dimensions than both the reduced opening and the second shape, and last displacing an expansion mandrel having a circular section to expand, in the plastic range, the pipe having a substantially cylindrical second shape to a cylindrical third shape.

Abstract: The invention concerns a method for casing a borehole which consists of successively lowering an unlimited plurality of strings of casing having a common diameter, the next one through the preceding one, to be installed one beneath the other and being sealingly connected. Thus a next casing (6) is lowered folded through the preceding casing (5) and the expansion process consists either in injecting pressurized fluid through the drillstring (54) towards the next casing (6) so as to re-inflate it, or the next casing (6) is a cylindrical pipe having a diameter smaller than the internal diameter of the preceding casing (5) and the expansion process consists in forcing a cylindrical gauge (52) from the top end (26) to the bottom bell (28) of the next casing (6) so as to increase its diameter to make it equal to the diameter of the preceding casing (5). The method can use a cementing shoe (34) and a metal-to-metal seal (29) between the casing string.

Abstract: A multi-structure pipe intended to transport a fluid, used in particular in oil production, including a first hollow and closed tubular structure having a set of substantially circumferential slits, each slit extending on an arc of more than 180° and defining a tension band extending with a helix shape along the said first tubular structure, and at least a second tubular structure having also at least a tension band also in helix shape of the same direction and pitch as the first tubular structure, and the tension bands of the first and second tubular structure being maintained at a fix distance from one another by support of the second tension band on the first tubular structure to provide the tension capacity of the pipe.

Abstract: The invention concerns a method for enhancing resistance to external pressure to a pipe installed in a previously cased borehole, which offers a passage through its opening of reduced size. Said method consists in lowering the pipe in a first shape (2) whereof the dimensions are smaller than the reduced opening, in deforming it to convert it from the first shape in a second shape substantially cylindrical (3) having a dimension larger than the reduced opening and characterized by the expansion of the cylindrical pipe of the second form by displacement of an expansion mandrel through the pipe, the peripheral expansion lying between 2 and 10% of the value of the initial perimeter.

Abstract: A well production assembly includes a production tree which has a lateral production passage extending laterally from a vertical bore of the tree. A tubing hanger, also having a lateral production passage, lands in the tree, with the lateral passages registering with each other. The junction of the lateral passages has flat, tapered sealed areas which mate with one another. An annulus passage extends vertically through the tubing hanger offset from and parallel to the tubing hanger vertical production passage. The annulus passage also has a lateral passage which registers with the lateral passage formed in the tree. The annulus lateral passages have a flat seal area at their junction. The tubing hanger has a downward facing hydraulic connector which registers with an upward facing hydraulic connector located on a shoulder formed in the bore. Once mated, the connectors provide hydraulic or other auxiliary fluid communication to downhole equipment.

Abstract: A well casing junction connects an upper string of casing to a pair of lower or branch strings that diverge from each other. The junction tool has an upper section and a pair of branch sections that join the upper section and each other. The junction tool is collapsed for running into the well along with casing. To collapse, a force is applied to opposite sides to create identical, deep depressions in the opposite sides of the junction tool. Once in position, internal pressure forces the depressions outward to assume an expanded position. A support member locates at the junction and between the two branch sections. The support member reduces stress that occurs from moving from the collapsed to the expanded position.

Abstract: A subsea wellhead assembly located at the sea floor that includes a subsea wellhead and a stationary blowout preventer mounted to the subsea wellhead for controlling a well during drilling. A drill pipe defines an annulus within the stationary blowout preventer. The drill pipe extends to a rotational drive mechanism on a drilling rig at the surface. A drilling head forms a seal against a drill pipe with a rotatable inner portion. The rotatable inner portion rotates with the drill pipe and prevents drilling fluid returns from flowing up the annulus around the drill pipe and prevents drilling fluid returns from discharging onto the seabed. The drilling head is mounted on top of the stationary blowout preventer. A riser extends upward from the drilling head and extends to a floating drilling rig. The riser has a lower end that connects into the drilling head below the drill pipe seal for receiving mud-returns flowing up around the annulus of the drill pipe.

Abstract: A well production assembly includes a production tree which has a lateral production passage extending laterally from a vertical bore of the tree. A tubing hanger, also having a lateral production passage, lands in the tree, with the lateral passages registering with each other. The junction of the lateral passages has flat, tapered sealed areas which mate with one another. An annulus passage extends vertically through the tubing hanger offset from and parallel to the tubing hanger vertical production passage. The annulus passage also has a lateral passage which registers with the lateral passage formed in the tree. The annulus lateral passages have a flat seal area at their junction. The tubing hanger has a downward facing hydraulic connector which registers with an upward facing hydraulic connector located on a shoulder formed in the bore. Once mated, the connectors provide hydraulic or other auxiliary fluid communication to downhole equipment.

Abstract: A high pressure subsea pipe, particularly for underwater use, has the ability to flex while being transported and installed. The pipe has a friction reinforcement structure made of overlapping layers increasing substantially the capacity of the pipe in longitudinal direction. The reinforcement layer may be a helical wrap, either cylindrical or conical, or conical sleeves nested within one another. An articulated carcass has turns of a helically wrapped main and ancillary wires, offering no axial slack in either tension or compression or in both directions while remaining flexible.

Abstract: A casing junction member connects in a well between a main casing and a lateral branch casing. The junction member has an upper end portion which connects to the main casing extending above the member. It has a lower end portion that is coaxial and connects into the main casing below the junction member. The junction member has a lateral section which joins the main section at a junction and extends downward for connecting to lateral branch casing. The junction between the main section and the lateral section has a lower perimeter portion that is generally in the shape of a parabola. A stiffening member is joined to the lower perimeter portion of this junction. The stiffening member is located in a plane containing the lower perimeter portion of the junction.

Abstract: A flexible pipe for subsea installation has a fluid impervious tube surrounded by a structure pipe. The structure pipe is a cylindrical monolithic member. It has at least two rows of slots extending along the length of the wall. The slots are evenly spaced apart, parallel and located on a helix. Each of the slots are in a row, which is also located on a helix, but extending in a different direction from the slot helix. Solid bands extend between the rows of slots. Arc members are located between each of the slots, the arc members joining the bands. The structure pipe surrounds a fluid impervious tube which is corrugated and metallic.

Abstract: A high pressure subsea pipe, particularly for underwater use, has the ability to flex while being transported and installed. The pipe has a friction reinforcement structure made of overlapping layers increasing substantially the capacity of the pipe in longitudinal direction. The reinforcement layer may be a helical wrap, either cylindrical or conical, or conical sleeves nested within one another. An articulated carcass has turns of a helically wrapped main and ancillary wires, offering no axial slack in either tension or compression or in both directions while remaining flexible.

Abstract: The radially deformable pipe of the invention is made up of at least two sections releaseably coupled end to end. The end of one of the sections has, over a predetermined axial length, an internal perimeter substantially equal to the external perimeter of the end of the other section, so as to form a male end adapted to be inserted in a female end. The extreme margin of the male end includes a locking bead adapted to fit in sealed manner in an internal groove of the female end behind a locking bead including the edge of this groove (9). The extreme margin of the female end is fitted into an external groove of the male end spaced from the locking bead by the said axial length.

Abstract: A process for mutually locking two elements screwed on one another, wherein it is provided that a portion of one of the elements covers a housing provided in the other element and overlaps an edge limiting said housing; said portion or a part thereof is then sheared level with said edge so that it penetrates in the housing, the shearing front then cooperating with the wall of the housing comprising the edge to form a stop opposing unscrewing. The process is more particularly applicable to the connecting of tubes used in offshore oil drilling and prospection.