Conoco Inc.

Continental Oil Company

Marvin L Peterson

Orwin G Maxson

Donald H Oertle

Norman W Hein, Jr

Charles F Putnik

Charles F Cole, Jr

Steven E Hawkins

Adolph A Sutko

Robert D Ohmart

Horace F House

A composite structure of lightweight is used as a tensioned tether element for mooring of offshore facilities. The composite structure comprises bonded inner and outer tubular members having an annular space therebetween. Aramid or other fibrous, high strength material is bonded to the inner surface of the outer tubular member to provide additional tensile strength thereto. The remainder of the annulus between the inner and outer tubing may be filled with a foam material such as polyurethane foam. The composite structure can be made so as to be of neutral, positive or negative buoyancy. The composite allows greater tensile loadings than steel materials by themselves at greatly reduced weight.

Dual wall steel and fiber composite mooring element for deep water

A composition which is particularly suitable for providing cathodic protection of metal structures is disclosed. The composition comprises a major amount of particulate anode material and a minor amount of a thixotropic carrier material. A method of using the composition is disclosed. Also, an apparatus which uses the composition is disclosed.

Sacrificial anode composition

Acoustic emissions are detected so that the amount of wear on the interior of a conduit can be directly determined. The acoustic emissions arise from plastic deformations and fractures caused by the fluid and particulate substances therein flowing through the conduit and impinging upon the interior surface of the conduit or by cavitation. The apparatus as disclosed has the capability to detect and also locate the surface area where wear is occurring.

Method and apparatus for erosion detection and location in hydrocarbon

A method for restricting uncontrolled fluid flow through a pipe by positioning a heat conductor through the pipe wall and in contact with fluid flowing through the pipe and cooling the heat transfer surfaces of the heat conductor to freeze a portion of the flowing fluid on the heat transfer surfaces. The freezing is continued to form a plug which substantially restricts or stops flow through the pipe.

Method for restricting uncontrolled fluid flow through a pipe

At least two types of reflective or emissive materials are applied in alternating manner to a pile or other object to be moved. Ultraviolet energy is emitted toward the materials and reflections or emissions therefrom are received by appropriate detector elements which convert the different respective reflected or emitted energy spectra into corresponding electrical signals for use by a processor device to determine the distance and rate which the pile or object is being moved. The calculated information is channeled to a suitable display and a permanent recording device.

Displacement measurement device and method

A pile driving hammer monitoring apparatus is disclosed to include a pressure wave sensor, such as a hydrophone, remotely located from the pile driving equipment for detecting pressure waves generated by the hammer striking a pile. The sensor generates a proportional analog electrical signal which is conditioned into a corresponding digital electrical signal and conveyed to a microcomputer. The microcomputer calculates the hammer blow rate over a predetermined time period or over a selectable time period or distance of pile movement. Data independent of the blow rate information is enterable into the microcomputer by means of presettable multi-position switches. The apparatus can be powered either by an alternating current source or a direct current source.

Method and apparatus for remotely monitoring and evaluating pile driving

The strength of a weld joint joining the end of a first structural member to a second structural member wherein at least a portion of the weld joint is subject to cyclic tensioning stress is improved by applying a compressive stress load to the weld joint. An advantageous application is to the weld joints joining tubular members of offshore platforms.

Compression stressed weld joints on offshore platforms

Sacrificial anode composition in cathodic protection process

A dual element strain gauge is placed near a welded or otherwise constrained joint on a structural member so as to provide a constraint factor. The location for the strain gauge must be selected to provide constraint factor that is preferably near either maximum or minimum value. The strain gauge is monitored to detect a change in the initial constraint factor, which indicates failure has begun or is imminent.

Constraint factor for structural monitoring

A sacrificial anode apparatus for providing cathodic protection of metal structures, a portion of which is in water is disclosed. The anode apparatus comprises:

Sacrificial anode apparatus

A corrosion resistant bimetallic structure which includes a pair of butt-welded steel elements having protected surfaces extending to the weld; spaced, protective overlays of corrosion resistant non-ferrous metal joined to portions of the protected surface of each steel element on opposed sides of the weld; and a non-ferrous metal bridging plate bridging the weld and joined to outer sides of the spaced protective overlays by welds using said corrosion resistant non-ferrous metal as the weld metal. The space between the bridging plate, the spaced ends of the protective layers and the steel elements adjacent the weld is sealed against ingress of corrosive liquid. In a method of making the described structure, the steel elements are welded in end-to-end alignment. Sections of each element spaced from the weld are then encased with a corrosion resistant non-ferrous metal. Each metal encasement is sealed against the steel, and the gap between the ends of the encasing sections of non-ferrous metal is filled with a secondary sealing material, such as an epoxy grout. Finally, the seals and weld are protectively enclosed under a bridging plate of the non-ferrous metal by welding the bridging plate to exposed surfaces of the non-ferrous metal encasements.

Bimetallic corrosion resistant structural joint and method of making same

A compressively stressed weld joint joining a first tubular member to a second tubular member is formed by sequentially:

Compression prestressed weld joints

A sacrificial anode apparatus for providing cathodic protection of metal structures, especially steel offshore platforms, is disclosed. The anode apparatus comprises (a) container for anode material, (b) anode material, and (c) means for continuously and/or periodically conveying said anode material to said container.

Crack initiation in metallic structural members subject to cyclic loading is predicted by sensing metallurgical changes taking place as a result of the cyclic loading. Fatigue loading produces a cycle comprising a condition described as fatigue relaxation followed by fatigue intensification. By monitoring this cycle, measured strain for a known applied load will increase or decrease. By monitoring the change in strain load, crack initiation can be predicted as fatigue relaxation becomes fatigue intensification. In a preferred embodiment, the strain gauge is mounted beneath a patch excluding ambient atmosphere during monitoring of the structural members.

Structural failure detection method

Early detection of cracks in non-permeable, structural members subject to stress is effected before the cracks traverse the member by:

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Ponca City, OK, United States of America

Marvin L Peterson