Abstract: New methods of manufacturing coiled tubing result in increased useful life of the coiled tubing string by creating an enhanced strip-to-strip weld zone having load bearing and/or fatigue resistance properties substantially equal to or greater than the load bearing and/or fatigue resistance properties of the strip base material. The enhanced weld zone is transition into the nominal tubing to reduce stress concentration.

Abstract: New methods of manufacturing coiled tubing result in increased useful life of the coiled tubing string by creating an enhanced strip-to-strip weld zone having load bearing and/or fatigue resistance properties substantially equal to or greater than the load bearing and/or fatigue resistance properties of the strip base material. The enhanced weld zone is transition into the nominal tubing to reduce stress concentration.

Abstract: A pump apparatus for use in a pump system of a well capable of exerting and releasing pressure on a pump fluid supplied to the pump apparatus. The pump apparatus includes a tubular body having a pump fluid space for communicating with the pump fluid and a chamber for receiving unpumped well fluid and for furnishing pumped well fluid to a wellhead of the well, wherein the pump fluid and the pumped well fluid remain separated. The pump apparatus includes a device located inside the tubular body and in contact with the pump fluid space for displacing the pumped well fluid from the chamber to the wellhead in response to the pump system exerting pressure on the pump fluid and for receiving the unpumped well fluid from a producing formation and delivering the unpumped well fluid to the chamber in response to the pump system releasing pressure on the pump fluid.

Abstract: A dual bias weld is an improved weld for joining strips to be formed into coiled tubing. Tubing is formed from a first strip and a second strip, the first and second strips being of the same width. A planar end surface is formed on an end of the first strip, the plane of the planar end surface being defined by a line lying along a top surface of the first strip at an acute angle with respect to the longitudinal direction of the first strip and a line lying along an edge surface of the first strip at an acute angle with respect to the longitudinal of the first strip. Similarly, a planar end surface is formed on an end of the second strip, the plane of the planar end surface being defined by a line lying along a top surface of the second strip at an acute angle with respect to the longitudinal direction of the second strip and a line lying along an edge surface of the second strip at an acute angle with respect to the longitudinal direction of the second strip.

Abstract: Preperforated tubing is produced by forming a perforation in flat strip of raw material, forming a hollow, cylindrical tube from the flat strip, and placing a removable plug into the perforation, so as to form a fluid-tight seal. A sealing element may be placed into the perforation. The perforation may comprise a hole, into which first and second countersinks may be formed. The sealing element may be placed into the first countersink, and the plug may be placed through the countersinks and the hole, such that the plug's body fills the hole and the plug's head fits within the second countersink.

Abstract: Preperforated tubing is produced by forming a perforation in flat strip of raw material, forming a hollow, cylindrical tube from the flat strip, and placing a removable plug into the perforation, so as to form a fluid-tight seal. A sealing element may be placed into the perforation. The perforation may comprise a hole, into which first and second countersinks may be formed. The sealing element may be placed into the first countersink, and the plug may be placed through the countersinks and the hole, such that the plug's body fills the hole and the plug's head fits within the second countersink.

Abstract: A dual bias weld is an improved weld for joining strips to be formed into coiled tubing. Tubing is formed from a first strip and a second strip, the first and second strips being of the same width. A planar end surface is formed on an end of the first strip, the plane of the planar end surface being defined by a line lying along a top surface of the first strip at an acute angle with respect to the longitudinal direction of the first strip and a line lying along an edge surface of the first strip at an acute angle with respect to the longitudinal of the first strip. Similarly, a planar end surface is formed on an end of the second strip, the plane of the planar end surface being defined by a line lying along a top surface of the second strip at an acute angle with respect to the longitudinal direction of the second strip and a line lying along an edge surface of the second strip at an acute angle with respect to the longitudinal direction of the second strip.

Abstract: A system for making a long length of seam-welded tubing from shorter lengths of flat metal strip which are spliced end-to-end and formed into tubular form and seam-welded. Adjoining ends of two successive lengths of the strip are trimmed at supplementary angles, one of which is an acute angle. The trimmed ends are abutted and welded, preferably with weldment extending beyond each such end. All surfaces of the weld are finished to match the dimensions of the strip. The tubing, along with the welded joints, is heat treated as the tubing is formed to produce a product substantially free of internal surface roughness along the splice welds.

Abstract: A system for making a long length of seam-welded tubing from shorter lengths of flat metal strip which are spliced end-to-end and formed into tubular form and seam-welded. Adjoining ends of two successive lengths of the strip are trimmed at supplementary angles, one of which is an acute angle. The trimmed ends are abutted and welded, preferably with weldment extending beyond each such end. All surfaces of the weld are finished to match the dimensions of the strip. The tubing, along with the welded joints, is heat treated as the tubing is formed to produce a product substantially free of internal surface roughness along the splice welds.