Abstract

A connector for connecting threaded ends of adjacent pipes, comprising a cylindrical body having threads formed at each end, the threads corresponding to the threads on the pipes to be connected; wherein a circumferential region (14, 18) of an outer wall of the body has a reduced diameter so as to provide a region of reduced wall thickness between the threads such that the bending stiffness of the connector is substantially similar to that of the pipes to be connected.

IPC Classes  ?

• E21B 17/042 - CouplingsJoints between rod and bit, or between rod and rod threaded
• F16L 15/00 - Screw-threaded jointsForms of screw-threads for such joints

Abstract

An electrode assembly for use in an electrical discharge acoustic source, comprises a conductive tip holder 54 that can be connected to a power supply, a discharge tip 52 connected to the conductive tip holder 54, and an insulating collar 60 surrounding the connection between the tip 52 and the holder 54 and having an aperture through which the discharge tip 52 projects; wherein the wall of the aperture in the tip holder 54 is provided with formations 59 holding sealing elements 58 that seal around the discharge tip 52.

IPC Classes  ?

• G01V 1/157 - Generating seismic energy using spark dischargesGenerating seismic energy using exploding wires
• G10K 15/06 - Sound-producing devices using electric discharge

Abstract

An electrical discharge acoustic source 16 comprises a power section 18, a control section 30, a bank of capacitors 24, and a discharge electrode arrangement 28; wherein the bank of capacitors 24 further comprises a switching arrangement 26 by which each capacitor in the bank 24 is independently connectable to an electrode in the discharge electrode arrangement 28 so as to provide a predetermined acoustic signal on operation of the discharge electrode arrangement 28. A method of generating an acoustic signal comprises independently configuring the connection of each electrode in the discharge electrode arrangement 28, and discharging the connected capacitors through the discharge electrode arrangement 28 so as to provide a predetermined acoustic output.

IPC Classes  ?

• G01V 1/157 - Generating seismic energy using spark dischargesGenerating seismic energy using exploding wires
• G10K 15/06 - Sound-producing devices using electric discharge

Abstract

A method of conducting borehole operations using a system including an elongate tubular conveyance that is moved through the borehole, the method comprising imposing a torsional vibration at a predetermined frequency on the tubular conveyance as it is moved through the borehole: wherein the predetermined frequency is obtained by determining the frequency-dependent mobility of the system based on the relationship between rotational velocity and torque for the system; and imposing torsional vibrations at a frequency where the relationship is optimised.

IPC Classes  ?

• E21B 7/24 - Drilling using vibrating or oscillating means, e.g. out-of-balance masses
• E21B 28/00 - Vibration generating arrangements for boreholes or wells, e.g. for stimulating production
• E21B 7/04 - Directional drilling

Abstract

An apparatus (10, 32, 46, 56, 66, 70) for deforming the shape of a tubular element (12) which comprises a compressible expansion body (18, 36, 50, 60, 66, 74) being locatable in proximity to an inner surface or an outer surface of a tubular element, the compressible expansion body being mountable on a tool body (16, 34, 48, 58, 72); at least one outer surface of the expansion body being contactable with the inner surface or the outer surface of the tubular element when the expansion body is in its uncompressed state, the tool body being moveable longitudinally along the tubular element; the expansion body being compressible against the inner surface or the outer surface of the tubular element by the longitudinal movement of the tool body longitudinally along the tubular element; and the compression of the expansion body against the inner surface or the outer surface of the tubular element causing deformation of the shape of the tubular element so as to change its diameter longitudinally along a portion of the tubular element.

IPC Classes  ?

• E21B 43/10 - Setting of casings, screens or liners in wells
• B21D 39/08 - Tube expanders

Abstract

A transformer comprising a circular ferrite structure (14) including a plurality of inwardly directed spokes (18), adjacent spokes being connected by cross-legs (20) which surround an opening inthe centre of the structure/a primary winding (26) around each cross-leg; and a secondary winding (28) around each spoke.

IPC Classes  ?

• H01F 27/24 - Magnetic cores

Abstract

A power transmission system for use with downhole equipment in a borehole, comprising a power source positioned at the surface providing a DC power supply and a downhole DC/DC converter, connected to the power source by a two-conductor cable and which takes the DC voltage supply as an input and provides an output DC supply at a different voltage to the DC power supply for provision to the downhole equipment.

IPC Classes  ?

• E21B 4/04 - Electric drives
• E21B 41/00 - Equipment or details not covered by groups
• E21B 43/12 - Methods or apparatus for controlling the flow of the obtained fluid to or in wells

Abstract

An apparatus (10) for expanding tubular elements (12), comprises a tool body (IS); an axially compressible expansion body (34) mounted on the tool body such that the outer surface of the expansion body is substantially the same outer diameter as that of the tool body; and means (30, 26) for axially compressing the expansion body such that its outer surface is expanded beyond the outer diameter of the tool body. A method for expanding tubular elements, comprises positioning an apparatus as claimed in any preceding claim at a predetermined position in the tubular element; and compressing the expansion body such that its outer surface expands against the inner wall of the tubular element and causes it to expand and deform permanently. The invention relates further to various applications of the apparatus for expanding tubular elements.

IPC Classes  ?

• E21B 43/10 - Setting of casings, screens or liners in wells

Abstract

A method of expanding a tubular element suitable for installation in a well, comprises installing an expander tool in the tubular element, the expander tool comprising: a flexible sleeve having an outer diameter less than or equal to the inner diameter of the tubular element; a cone expander section (10) on which the sleeve (18) is mounted, a cone (12) having a narrow end that fits inside the sleeve and which increases from the narrow end to a maximum at a base that is greater than the inner diameter of the sleeve but less than the inner diameter of the tubular element; and a elongate mandrel (14) extending from the end of the cone expander section on the opposite side to the narrow end; positioning the expander tool including the sleeve at a predetermined location in the tubular element to be expanded; fixing the position of the sleeve; urging the expander section through the sleeve from one end to the other so as to expand the sleeve against the inside of the tubular member and cause it in turn to expand, the expander being urged through the (preferably lubricated) sleeve until it exits the other end of the sleeve; allowing the sleeve to contract around the mandrel; and moving the expander tool with the sleeve located around the mandrel away from the expanded location.

IPC Classes  ?

• B21D 39/20 - Tube expanders with mandrels, e.g. expandable
• E21B 43/10 - Setting of casings, screens or liners in wells