A pull head assembly for quick attachment to a flexible pipe is provided. The pull head assembly has three subsections. A collet assembly is mounted to the end of a flexible pipe. A mandrel assembly is adapted to go over the collet assembly. A lead screw assembly positions the mandrel assembly over the collet assembly and acts as an attachment point for pulling the flexible pipe and pull head assembly from one location to another. After pulling the flexible pipe and pull head assembly from one location to another, the mandrel assembly and lead screw assembly can be removed, and the collet assembly can act as a temporary fitting for the flexible pipe.

A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

The present invention relates to a downhole production casing string for insertion in a borehole in a reservoir, the downhole production casing string having a first end nearest a top of the borehole and a second end furthest away from the top, the downhole production casing string extending along a longitudinal axis and comprising at least one opening which during production allows hydrocarbon-containing fluid from the reservoir into the downhole production casing string, a plurality of casing parts having end sections and a base section between the end sections, the base section having an outer diameter, and at least one annular projecting element having an outer face and at least one helical groove arranged in or on the outer face and having an overall outer diameter which is larger than the outer diameter of the base section. Furthermore, the invention relates to a downhole production casing string system for completing a well downhole and to a method of implementing a production casing string according to the invention.

The present invention relates to a downhole production casing string for insertion in a borehole in a reservoir, the downhole production casing string having a first end nearest a top of the borehole and a second end furthest away from the top, the downhole production casing string extending along a longitudinal axis and comprising at least one opening which during production allows hydrocarbon-containing fluid from the reservoir into the downhole production casing string, a plurality of casing parts having end sections and a base section between the end sections, the base section having an outer diameter, and at least one annular projecting element having an outer face and at least one helical groove arranged in or on the outer face and having an overall outer diameter which is larger than the outer diameter of the base section. Furthermore, the invention relates to a downhole production casing string system for completing a well downhole and to a method of implementing a production casing string according to the invention.

A cutting head has a mounting bracket for attachment to a pipe and a cutter wheel. A double tapered bearing is connected between the mounting bracket and the cutter wheel. The bearing allows the cutter wheel to be rotated without rotation of the pipe. A drive shaft connector on the cutter wheel is connectable to a pilot hole drive shaft for rotating the cutter wheel and pulling it and the pipe. A pilot hole is drilled in a conventional manner. The pipe is attached to the mounting bracket and an end of the pilot hole drive shaft is then connected to the cutter wheel. Simultaneously the pilot hole is enlarged and the pipe and cutter wheel are pulled along the enlarged hole by the drive shaft. The cutter wheel advances along the pilot hole and the pipe is simultaneously advanced through the enlarged hole immediately behind the cutter wheel.

A cable retention and release mechanism includes a cable gripping device including a cable passage. A cable extends through the cable passage. A cable gripping device collar is movably coupled around the cable gripping device. An outer cable gripping device surface is seated against a cable gripping device receiving inner surface preventing movement of the cable gripping device relative to the cable gripping device collar. The cable gripping device receiving inner surface clamps the cable gripping device on the cable and prevents sliding movement of the cable. A jack is movably coupled with the cable gripping device collar. In a first engaged position the jack is engaged against the cable gripping device proximal end. In a second engaged position the jack unseats the outer cable gripping device surface from the cable gripping device receiving inner surface and releases the clamping of the cable.

A method to facilitate the extraction of hydrocarbon from a coal seam gas formation is described that includes. : (a) drilling a wellbore using a drill string to access the coal seam gas formation; (b) perforating a section of the drill string; (c) abandoning a section of the drill string in the wellbore; (d) setting a temporary plug to isolate the abandoned section of the drill string and the wellbore; (e) installing a production tubing string above the temporary plug to create a fluid passageway ; (f) displacing a fluid above the temporary plug ; (g) removing the temporary plug to create an initial stimulated reservoir volume and, resultantly, at least partially filling an annulus formed between the abandoned section of the drill string and the wellbore wall with coal fragments; and (h) extracting hydrocarbon from the coal seam gas formation via the fluid passageway to create an expanding stimulated reservoir volume.

Disclosed is a rupture disc assembly for use in making a temporary seal in a vessel such as a casing string. The rupture disc assembly may include a rupture disc having a side surface that has a shallow angle taper inward towards a bottom surface of the rupture disc, and a mounting apparatus to support the rupture disc so that the rupture disc forms the temporary seal. When a disc working pressure is applied to a top surface of the rupture disc, engagement/force transmission between the rupture disc and the mounting apparatus produces enough radial compression in the rupture disc due to the shallow angle taper to significantly mitigate or cancel tensile stresses thereby avoiding the rupture disc from breaking. The rupture disc may be configured to break when the rupture disc is subjected to a disc working pressure that is greater than the disc rupture pressure, thereby removing the temporary seal. An axial abutment surface feature may be provided which is configured and operable to limit downward axial movement of the rupture disc relative to said disc support mechanism and thus be operable to restrict the amount of compression said tapered wall surface of said disc support mechanism can exert on said at least a portion of said rupture disc when the top surface of the rupture disc is subjected to said hydraulic pressure within the well.

Disclosed is a rupture disc assembly for use in making a temporary seal in a vessel such as a casing string. The rupture disc assembly may include a rupture disc having a side surface that has a shallow angle taper inward towards a bottom surface of the rupture disc, and a mounting apparatus to support the rupture disc so that the rupture disc forms the temporary seal. When a disc working pressure is applied to a top surface of the rupture disc, engagement/force transmission between the rupture disc and the mounting apparatus produces enough radial compression in the rupture disc due to the shallow angle taper to significantly mitigate or cancel tensile stresses thereby avoiding the rupture disc from breaking. The rupture disc may be configured to break when the rupture disc is subjected to a disc working pressure that is greater than the disc rupture pressure, thereby removing the temporary seal. An axial abutment surface feature may be provided which is configured and operable to limit downward axial movement of the rupture disc relative to said disc support mechanism and thus be operable to restrict the amount of compression said tapered wall surface of said disc support mechanism can exert on said at least a portion of said rupture disc when the top surface of the rupture disc is subjected to said hydraulic pressure within the well.