Abstract: Methods of forming a lined tubular member are described herein. A method includes forming at least one corrugated portion in a conduit having at least one substantially tapered end to form a corrugated conduit, providing the corrugated conduit to a tubular member; and expanding the corrugated conduit while the corrugated conduit is inside the tubular member.

Abstract: Methods of forming a lined tubular member are described herein. A method includes forming at least one corrugated portion in a conduit having at least one substantially tapered end to form a corrugated conduit, providing the corrugated conduit to a tubular member; and expanding the corrugated conduit while the corrugated conduit is inside the tubular member.

Abstract: A corrugated conduit and method of expanding to form a lined tubular member are described. In some embodiments, a corrugated conduit may be expandable. The corrugated conduit may be inserted into a tubular member and hydraulically or otherwise expanded against walls of the tubular member to strengthen and/or seal the tubular member when the corrugated conduit is expanded in the tubular member. In certain embodiments, the tubular member is a drill stem.

Abstract: A lined conduit formed by decorrugating a corrugated liner conduit inside a first conduit is described. A method and apparatus for forming the lined conduit are also described. The corrugated liner conduit may be positioned inside the first conduit. Each end portion of the corrugated liner conduit may be coupled to a hydraulic expander. Each hydraulic expander may include a hydraulic cylinder. Each hydraulic cylinder may include a piston rod with an opening along the length of the piston rod. The corrugated liner conduit may be evacuated through a valve assembly coupled to the passageway in one of the piston rods. The evacuated corrugated liner conduit may be pressurized with fluid from a fluid source coupled to the valve assembly. Pressurizing the corrugated liner conduit may expand corrugations in the corrugated liner conduit to form a decorrugated liner in the first conduit.

Abstract: A lined conduit formed by decorrugating a corrugated liner conduit inside a first conduit is described. A method and apparatus for forming the lined conduit are also described. The corrugated liner conduit may be positioned inside the first conduit. Each end portion of the corrugated liner conduit may be coupled to a hydraulic expander. Each hydraulic expander may include a hydraulic cylinder. Each hydraulic cylinder may include a piston rod with an opening along the length of the piston rod. The corrugated liner conduit may be evacuated through a valve assembly coupled to the passageway in one of the piston rods. The evacuated corrugated liner conduit may be pressurized with fluid from a fluid source coupled to the valve assembly. Pressurizing the corrugated liner conduit may expand corrugations in the corrugated liner conduit to form a decorrugated liner in the first conduit.

Abstract: A machine may produce a tube having textured internal and external surfaces in a single operation. Inner and outer knurling tools may form the textured surfaces. The texturing of the internal and external surfaces may be helical patterns of ribs and grooves. The height of the ribs formed in the internal and external surfaces may be less than about 35 mils. The angles of the patterns relative to a longitudinal axis of the tube may be less than about 45°. The angle of the helical pattern allows textured tubes to be used as heat exchanger elements wherein flow is directed substantially coaxial to the longitudinal axes of the tubes. The helical pattern formed in the external surface may be oriented in a right hand or left hand helical orientation. Similarly, the helical pattern formed in the internal surface may be oriented in a right hand or left hand orientation.

Abstract: A conduit modifier may be used to corrugate at least a portion of a conduit. The conduit modifier may include at least a first plurality of rollers arranged in a first pattern around a passageway. The first plurality of rollers may form ridges and grooves lengthwise along a conduit passing through the passageway. A second plurality of rollers arranged in a second pattern around the passageway may compress ridges formed by the first set of rollers. The ridges may be formed such that a distance from a central axis of the conduit to a highest portion of an outer surface of a ridge is substantially equal to a distance from the central axis of the conduit to an outer surface of the un-corrugated portion of the conduit. The corrugated portion of the modified conduit may be expandable.

Abstract: A machine may produce a tube having textured internal and external surfaces in a single operation. Inner and outer knurling tools may form the textured surfaces. The texturing of the internal and external surfaces may be helical patterns of ribs and grooves. The height of the ribs formed in the internal and external surfaces may be less than about 35 mils. The angles of the patterns relative to a longitudinal axis of the tube may be less than about 45°. The angle of the helical pattern allows textured tubes to be used as heat exchanger elements wherein flow is directed substantially coaxial to the longitudinal axes of the tubes. The helical pattern formed in the external surface may be oriented in a right hand or left hand helical orientation. Similarly, the helical pattern formed in the internal surface may be oriented in a right hand or left hand orientation.

Abstract: A conduit modifier may be used to corrugate at least a portion of a conduit. The conduit modifier may include at least a first plurality of rollers arranged in a first pattern around a passageway. The first plurality of rollers may form ridges and grooves lengthwise along a conduit passing through the passageway. A second plurality of rollers arranged in a second pattern around the passageway may compress ridges formed by the first set of rollers. The ridges may be formed such that a distance from a central axis of the conduit to a highest portion of an outer surface of a ridge is substantially equal to a distance from the central axis of the conduit to an outer surface of the un-corrugated portion of the conduit. The corrugated portion of the modified conduit may be expandable.

Abstract: A machine may produce a tube having textured internal and external surfaces in a single operation. Inner and outer knurling tools may form the textured surfaces. The texturing of the internal and external surfaces may be helical patterns of ribs and grooves. The height of the ribs formed in the internal and external surfaces may be less than about 35 mils. The angles of the patterns relative to a longitudinal axis of the tube may be less than about 45°. The angle of the helical pattern allows textured tubes to be used as heat exchanger elements wherein flow is directed substantially coaxial to the longitudinal axes of the tubes. The helical pattern formed in the external surface may be oriented in a right hand or left hand helical orientation. Similarly, the helical pattern formed in the internal surface may be oriented in a right hand or left hand orientation.

Abstract: A corrugated heat exchanger element may have grooves and ribs on the interior and exterior surfaces of the tube. The corrugations on the tube may be linear corrugations or helical corrugations. The texturing of the interior and exterior surfaces of the tube, and the corrugations in the tube may provide a heat exchanger element that has a large surface area. The surface texturing and corrugations may also provide a heat exchanger element that promotes internal mixing of fluids that flow by and through the element. Increased internal mixing and increased surface area of an element may allow the heat exchanger element to have a high heat transfer coefficient. A heat exchanger element or heat exchanger elements may be assembled into a heat exchanger that has a high overall heat transfer coefficient. Ends of the heat exchanger element may be pointed to facilitate attachment of the element to a support structure.

Abstract: A corrugated heat exchanger element may have grooves and ribs on the interior and exterior surfaces of the tube. The corrugations on the tube may be linear corrugations or helical corrugations. The texturing of the interior and exterior surfaces of the tube, and the corrugations in the tube may provide a heat exchanger element that has a large surface area. The surface texturing and corrugations may also provide a heat exchanger element that promotes internal mixing of fluids that flow by and through the element. Increased internal mixing and increased surface area of an element may allow the heat exchanger element to have a high heat transfer coefficient. A heat exchanger element or heat exchanger elements may be assembled into a heat exchanger that has a high overall heat transfer coefficient. Ends of the heat exchanger element may be pointed to facilitate attachment of the element to a support structure.

Abstract: A machine may produce a tube having textured internal and external surfaces in a single operation. Inner and outer knurling tools may form the textured surfaces. The texturing of the internal and external surfaces may be helical patterns of ribs and grooves. The height of the ribs formed in the internal and external surfaces may be less than about 35 mils. The angles of the patterns relative to a longitudinal axis of the tube may be less than about 45°. The angle of the helical pattern allows textured tubes to be used as heat exchanger elements wherein flow is directed substantially coaxial to the longitudinal axes of the tubes. The helical pattern formed in the external surface may be oriented in a right hand or left hand helical orientation. Similarly, the helical pattern formed in the internal surface may be oriented in a right hand or left hand orientation.

Abstract: Multi-passage heat exchange element which includes an elongated central first fluid passage for passage of a first fluid of a heat exchanger, a plurality of substantially helically convoluted second fluid passages for a second fluid of a heat exchanger, the second fluid passages substantially helically surrounding at least a portion of the elongated central passage, and a plurality of substantially helically convoluted first fluid passages for passage of the first fluid of a heat exchanger, the first fluid passages substantially surrounding at least a portion of the second fluid passages.

Abstract: Multi-passage heat exchange element which includes an elongated central first fluid passage for passage of a first fluid of a heat exchanger, a plurality of substantially helically convoluted second fluid passages for a second fluid of a heat exchanger, the second fluid passages substantially helically surrounding at least a portion of the elongated central passage, and a plurality of substantially helically convoluted first fluid passages for passage of the first fluid of a heat exchanger, the first fluid passages substantially surrounding at least a portion of the second fluid passages.