Threaded connections utilizing composite materials
AssigneesKenneth J. Carstensen, Lawrence P. Moore, John M. Hooks
InventorsKenneth J. Carstensen, Lawrence P. Moore, John P. Biro
Life of this patent
Estimating the term…
Abstract
For threaded connections for oil and gas applications using tubular goods of composite materials, substantially greater make up torque can be applied, with significantly improved tensile and sealing properties, by incorporating stress-relieving conical gradient sections adjacent each end of the threaded section of the composite member. Joining each of two composite tubular members to a single double ended male member having complementary surfaces, circumferential distortion is not concentrated at the end regions of the threaded sections but is distributed, relieving stresses and allowing increased makeup torque to be applied, greatly expanding the useful parameters of fiber reinforced tubular products.
Claims37
A coupling for threaded tubular goods for high pressure applications, comprising:
- a pair of female tubular members having internal threaded regions adjacent their ends;
- and
- a male pin member having a pair of tapered threaded regions extending oppositely from a central portion thereof, each of the tubular members and the pin member having a pair of unthreaded conical ring surfaces, one on each side of each of the threaded regions therein, the conical ring surfaces being opposed and in mating relation when the tubular members and the pin member are engaged and the conical ring surfaces being angled relative to the taper of the threaded region to engage with increasing force as the thread engagement increases.
A threaded connection utilizing a combination of fiber reinforced plastic female members and a double-ended male connecting member, comprising the combination of:
- a pair of female members having internal threaded regions;
- a single double-ended male member having a pair of oppositely extending threaded regions for receiving the female members in mating relation, and a means for providing a stress gradient disposed in the members adjacent each opposite end of each threaded region.
A threaded connection comprising:
- a double ended metal male member having a threaded region with a predetermined thread taper of opposite angle on each side of a central region, the male member including conical tapered bearing surfaces adjacent each end of each threaded region and angled acutely in excess of 2.degree. relative to the thread taper;
- and
- a pair of female FRP members having threaded regions, each of which is in mating relation individually with a different threaded region of the male member, and tapered bearing surfaces engaging those of the male member when the threaded regions are in engagement.
A threaded connection comprising:
- a double ended metal male member having a pair of threaded regions, each with a predetermined thread taper of opposite angle on a different side of a central region, the male member including conical tapered bearing surfaces adjacent each end of each threaded region and angled with selected angles relative to the thread taper;
- a pair of female FRP members having threaded regions mating individually with the different threaded regions of the male member, tapered bearing surfaces engaging those of the male member and facing ends when engaged on the male member;
- and
- wherein, the makeup torque is distributed between the threaded regions and the bearing surfaces such that at least one-third of the torque is absorbed in each of the bearing surfaces at full makeup, and wherein the connection further includes a radial ring disposed between and in engagement with the facing ends of the female members, and under a compressive loading in excess of 5,000 psi when the connection is fully made up.
A double-ended male member for interconnecting a pair of FRP tubular members comprising:
- a metal body having a substantially constant inner diameter and a pair of inwardly diverging male threaded regions on opposite sides of a central region;
- two pairs of stress gradient tapers on the male member, each one of the stress gradient tapers being disposed adjacent an opposite end of a different one of the threaded regions;
- the stress gradient tapers comprising conical surfaces having selected angles diverging at greater angles than the tapers of the threaded regions;
- and
- an O-ring disposed adjacent each different end of the male member in the conical surface thereat.
A threaded fiber reinforced plastic tubular product for high tensile and high pressure applications, comprising:
- a tubular walled body of fiber reinforced plastic, the fiber reinforcement comprising wound filament reinforcement having both axial and circumferential components;
- the tubular walled body including a diverging end portion of substantial thickness having an interior diverging threaded region including filament reinforcement and having a predetermined inner thread taper, the body terminating in a transverse end surface;
- and
- the body further including conical stress gradient surfaces adjacent each end of the threaded region, one conical surface being adjacent the end surface of the tubular body and at an angle of 2.degree. to 10.degree. relative to the inner thread taper, and the other conical surface being interior to the tubular member and at an angle of 5.degree. to 20.degree. relative to the inner thread taper.
A connection for two tubular FRP products comprising:
- a first tubular element of FRP composite material having an end length with an interior female thread region, and including a pair of conical gradient surfaces, one on each side of the thread region, and
- a second tubular element of FRP composite material having an end length with an exterior male thread region, and including a pair of conical gradient surfaces, one on each side of the thread region, the male thread region and conical gradient surfaces mating with the thread region and conical gradient surfaces on the first tubular element and having angles relative to the thread region of torque to provide stress absorption at the regions of the conical gradient surfaces when the tubular elements are fully engaged.
A connection for threaded tubular products utilizing fiber reinforced plastic bodies comprising:
- a pair of FRP tubular members having female threads adjacent the ends therefore and including filament wound reinforcement;
- a double-ended pin joining the tubular members and having a body of substantially fiber-reinforced plastic;
- a pair of spaced apart threaded inserts mounted on the pin, the inserts having separate thread regions thereon each mating separately with the threads of a different tubular member, and the tubular members and pin each including conical gradient surfaces on opposite sides of the thread regions, the conical gradient surfaces being complementary and engaging when the threaded regions are made up.
A connection for threaded tubular goods at least one of which is principally of FRP material comprising:
- a first tubular body having an FRP body and a female thread region, and including a pair of conical gradient sections, one on each side of the thread region;
- and
- a second tubular body having a male thread region and including a pair of conical gradient sections, one on each side of the male thread region, the female and male thread regions and conical gradient sections mating when the tubular bodies are in full engagement, the length, diameter and taper of the conical gradient sections being chosen to provide interference sufficient to reduce deformation in the regions of the bodies adjacent to the thread region on full engagement.
Dependencies are inferred from the claim text.