Abstract: A protective cover for protecting a wellhead mandrel and related equipment of a subsea wellhead when the drilling and producing equipment is removed. The protective cover is installed and removed using a pipe or cable running string with provisions for using either a hydraulic jet, a Remotely Operated Vehicle (ROV) or surface rig movements to position the cover.

Abstract: A hydraulic control umbilical is disclosed for supporting a plurality of hydraulic control lines along a riser between a surface facility and a subsea completion. The umbilical provides a skin encircling the riser substantially its entire length with means for supporting the skin about the riser and means for supporting the hydraulic control lines within the skin. A method for deploying and retrieving the hydraulic control umbilical is also disclosed.

Abstract: Methods for the early detection of gas kicks in marine risers (10) include monitoring a downhole absolute pressure and a downhole differential pressure of a riser section (11) positioned just above the blowout preventer (18). The absolute pressure is used to calculate an average density of mud or mud/gas mixture in the entire riser (10). The differential pressure across the riser section (11) is used to calculate an average density of mud or mud/gas mixture in riser section (11). An unfavorable comparison between the calculated density for the mud or mud/gas mixture in the riser section (11) and the calculated density for the mud or mud/gas mixture in the entire riser (10) is used to detect the onset of a gas kick and to alert the operator. Alternatively, the measured differential pressure across the riser section (11) can be compared with an expected downhole differential pressure. Unfavorable comparisons of the measured and expected differential pressures indicate the onset of a gas kick.

Abstract: The present invention provides methods for processing and displaying seismic data to emphasize potential hydrocarbon bearing strata. The methods treat measured attributes from the seismic data as components of a vector, estimate a background vector which represents uninteresting geologic behavior, and then form at least one new attribute which quantifies departures from this uninteresting behavior. The new attributes(s) and other attributes are then appropriately displayed.

Abstract: A method is described for conducting well operations from a floating platform that may be moved to various locations above subterranean formations. Marine risers that have been previously connected to the platform flex sufficiently to allow this movement. The mobility of the platform allows well drilling, completion, producing, and workover activities to be conducted simultaneously through the risers attached to the platform. The mobility of the platform also allows new wells to be drilled at more preferable locations than those that would be available from a fixed bottom supported well template.

Abstract: Method of utilizing a jack-up well drilling rig in shallow water to drill an isolated well having an unsupported well conductor, and subsequently to attach a reinforcing frame near the water line and to drive pile through the frame into the ocean floor without moving the jack-up rig off location.

Abstract: Both an offshore platform mating system and method are disclosed in which adjacent first and second jacket sections are provided with a plurality of corresponding docking poles and receptacles, respectively. Alignment of the adjacent jacket sections is facilitated by using at least one extended or lead docking pole on the first jacket section which projects further toward the second jacket section than do the other docking poles and is thus the first to engage one of the horizontally aligned receptacles when the first and second jacket sections vertically approach. Mating procedures for the first and second jacket sections continue with rotational alignment of the first and second jacket sections about the lead docking pole which acts as a pivot while alignment of the other receptacles is adjusted with respect to the other docking poles.

Abstract: An apparatus of reinforcing a hollow underwater member of an offshore platform which includes removable power-actuated motors, retaining means for preventing rotational movement of the motors relative to the retaining means while permitting axial movement of the motors, a drill and tap operatively connected to and driven by the motors for forming at least one port through a side wall of the hollow underwater member, and means operatively engageable with the motors for controlling the axial movement of the drill and tap in at least one direction during a port-forming operation.

Abstract: An offshore platform mating system of the present invention is disclosed in which an upwardly open lower receptacle is provided on upper extensions of leg portions of a jacket bottom section of the offshore platform for receiving a mating pin so as to project a docking pole upwardly. Downwardly open upper receptacles are provided on the lower extensions of each leg portion of the corresponding jacket top section and are disposed to receive the upwardly projecting docking pole of the mating pin. A connection is provided for securing the jacket top section to the jacket bottom section. A method is also disclosed for installing the offshore platform utilizing the mating pins.

Abstract: A hydraulic system has a filter that filters only when the fluid is flowing in one direction. The filter is located in a flow passage between a hydraulic fluid source and a valve in a well. The source supplies hydraulic fluid pressure in a forward direction to keep the valve open. A bypass passage allows hydraulic fluid to bypass the filter. A check valve located in the bypass passage prevents forward flowing fluid from flowing through the bypass passage. If hydraulic pressure is lost, hydraulic fluid will return through the bypass passage, rather than flowing through the filter, to allow the valve to quickly close.

Abstract: A wellhead apparatus and a method for positioning the apparatus on the ocean floor in combination with means for sinking it into the ocean floor. The wellhead apparatus is equipped with a venturi suction device and a central opening for receiving a well conductor pipe. The apparatus provides a well base structure that is highly stable, capable of taking high vertical and lateral loads, and can be controlled during installation to be either truly plumb or positioned at a predetermined angle relative to the vertical.

Abstract: A well valve assembly is disclosed for the control of well fluids that flow in the tubing and the annulus of a well. The well valve assembly consists of two parts, the first part being a housing that forms a portion of the well that has flow openings defined between the tubing and the annulus. The second portion of the well valve apparatus comprises a valve insert that may be lowered down through the well tubing and latched in a position adjacent the housing means. By proper selection and location of seals and flow passages on the valve insert well fluids in the tubing and the annulus may be controlled in a predetermined manner. Since valve inserts having different configurations may be interchanged within the same housing, the well valve assembly may interchangeably direct the flow of fluids within the well.

Abstract: A quick release grouting valve system is disclosed in which the valve system is provided in a first portion and a second portion which are joined together by a locking mechanism which is releasable by ROV manipulation of a protruding release handle relative to and adjacent protruding stationary handle.

Abstract: A method and apparatus are disclosed for use in reduction of well assembly time. A dual hanger casing head is supported by a previously driven drive pipe at the desired surface location of the well. A diverter assembly is connected to the upper end of the dual hanger casing head. Both a large diameter casing assembly and a small diameter casing assembly are installed downwardly through the diverter assembly and supported within the dual hanger casing head, prior to disconnection and removal of the diverter assembly from the top of the dual hanger casing head. Removal of the diverter assembly only after the installation of both casing assemblies significantly reduces the well assembly time, and reduces the risk to the equipment and personnel associated with the well assembly process.

Abstract: A vessel wave heading control apparatus is disclosed for use on a floating vessel. Linear acceleration signals from two accelerometers, which sense the rotational acceleration of the vessel due to waves which impact the vessel from a particular direction, are processed by a computer which subsequently produces vessel heading change signals to the steering and propulsion means of the vessel. These signals indicate the required heading and required rate of change of vessel heading necessary to turn the vessel into the direction of the oncoming waves in a timely manner.

Abstract: A utility bridge suitable for connecting offshore facilities such as offshore platforms is disclosed in which a plurality of helical pipelines provide flow communication between the facilities and relative movement of the facilities in response to environmental forces is provided for by helical pipelines with torsion expansion loops supported by a substantially rigid frame of the utility bridge which has means to prevent coupling of dynamic forces between the respective offshore facilities.

Abstract: Method and apparatus for reinforcing a shallow water unsupported well conductor by positioning a well jacket adjacent the well conductor, raising the jacket to a selected height above the ocean floor, driving pile through the legs of the jacket, connecting each pile to a surrounding leg and operatively connecting the jacket to the well conductor with the jacket being supported on the piles above the ocean floor.

Abstract: A system and method for grouting skirt piles in skirt sleeves at the bottom of a deep water offshore platform. A series of spaced apart grout inlets are located on the outer wall of each sleeve and are adapted to be engaged by the end of a flexible grout line by making use of an underwater vehicle to make the connection.

Abstract: A marine cable for detecting converted shear waves reflected from the strata beneath a body of water in response to a compressional wave generated in the body of water. The cable comprises a jacket, a mount attached to the stress member, a geophone positioned in the mount, a first weight assembly attached to the stress member and positioned proximate a first end of the mount and a second weight assembly positioned proximate a second end of the mount. The mount is sized and made of a material so that its weight is sufficient to cause at least the portion of the cable jacket that is adjacent the mount to contact the seafloor. The first and second weight assemblies are sized and made of material so that their respective weights cause at least the portion of the cable jacket that is adjacent to the respective weight assemblies to contact the seafloor.

Abstract: A wellhead apparatus and a method for positioning the apparatus on the ocean floor. The wellhead apparatus is equipped with a removable pump and a central opening for receiving a well conductor pipe. The apparatus provides a well base structure that is highly stable, capable of taking high vertical and lateral loads, and can be controlled during installation to be either truly plumb or positioned at a predetermined angle relative to the vertical.