Abstract: Disclosed is a production tree (10) with a top block (mandrel) (12) of the tree provided with a cone-shaped male connector member (14) which also functions as a manifold, and called a cone seal manifold, by having a plurality of shuttle valves (66) which, in the production mode connect umbilical hydraulic control lines (44) to valve actuator control lines (42). In the workover mode, a running tool (132) having a mating bell-shaped female connector member (134) engages the cone seal manifold (14) and moves the shuttle valves (66) to disconnect the umbilical control lines (44) from the valve actuator control lines (42) and to open the valve actuator control lines (42) to rig hydraulic control lines in the running tool (132) through the mating cone seal surfaces (134,56). Normally closed passageways (112) in the cone (56) of the cone seal manifold (14) are opened by fluid pressure from the rig control lines.

Abstract: A metal support ring is located between a housing and a wellhead for reducing bending movement of the wellhead relative to the housing. The support ring has a plurality of circumferentially extending ribs for engaging the bore of the housing. The ribs are parallel to and vertically spaced apart from each other. Each rib protrudes outwardly from the wellhead a distance greater than the inner diameter of the housing. This causes the ribs to deflect in an interference fit when the wellhead is inserted into the housing.

Abstract: A drilling template for multiple wells has a dummy post on the template associate with each wellhead position and a wellhead connector is transferable between the dummy post and wellhead during completion and workover operations. A subsea wellhead is provided with a guide frame on which a dummy post is supported permitting the wellhead connector to be transferred between the dummy post and the wellhead. The wellhead includes a landing nipple and tubing hanger which permit the tubing hanger to tilt relative to the casing head without breaking the seal between the hanger and nipple. The wellhead connector is latched and released from the tubing head by reciprocation of a control sleeve and the connector is held in the unlatched position by a releasable lock. The wellhead connector includes a plug having a metal seal held in compression together with a resilient seal.

Abstract: An improved annular seal between tubular members in a subsea wellhead having an annular seal member with a U shape in section with the opening facing upwardly and two interengaged annular wedges for energizing the sealing surfaces of the inner and outer portions of the seal member at different levels. The interengagement of the wedges includes sufficient play to provide proper energizing of both inner and outer sealing surfaces at the same time. Further, the inner sealing surface is positioned at a much higher level than the outer sealing surface and close to the upper end of the inner member in which it is to seal to minimize the setting force for the inner sleeve and to minimize the amount of drag the seal will incur when retrieved. Also, the location of the outer sealing surface close to the inner member shoulder minimizes the reaction path of the lockdown sleeve.

Abstract: A subsea hydraulic coupling has a pair of vertically spaced apart receptacles, each mounted to a different subsea well subassembly. A connector is lowered from the surface into engagement with the receptacles. The receptacles have radial ports. The connector has radial pistons that mate with the ports. Each piston has a flow passage extending through it. A communication passage extends from the flow passage of each piston through the body of the connector to a source of hydraulic fluid pressure. The connector body has a bore with a cam located inside. The cam, when actuated by hydraulic fluid pressure, pushes the pistons outwardly to engage the receptacle ports.

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.

Abstract: An improvement in an offshore well having a main casing penetrating subterranean formations below the bottom of the water and protruding upwardly through the water with a wellhead affixed above the surface of the water and a boat landing connected with the main casing. The improvement comprises a plurality of at least three anchor piles driven into the bottom at respective azimuths and distances about the well with the well anchored thereto via cables, the cables running upwardly through pulleys disposed a predetermined distance, such as 15 feet, below the surface of the water so as to anchor the well against lateral forces, yet satisfy Marine Maritime Service regulations and allow maneuvering of boats about the well. Also disclosed are typical and preferred structures including sizes and the like.

Abstract: A drilling template for multiple wells has a dummy post on the template associate with each wellhead position and a wellhead connector is transferable between the dummy post and wellhead during completion and workover operations. A subsea wellhead is provided with a guide frame on which a dummy post is supported permitting the wellhead connector to be transferred between the dummy post and the wellhead. The wellhead includes a landing nipple and tubing hanger which permit the tubing hanger to tilt relative to the casing head without breaking the seal between the hanger and nipple. The wellhead connector is latched and released from the tubing hanger by reciprocation of a control sleeve and the connector is held in the unlatched position by a releasable lock. The wellhead connector includes a plug having a metal seal held in compression together with a resilient seal.

Abstract: A subsea wellhead structure including a casing hanger having an exterior downwardly facing shoulder for landing within a well bore, a central bore, means for connecting a casing thereto, an upper exterior surface tapering downwardly and outwardly, and an external surface below said shoulder tapering downwardly and inwardly for centering said hanger on landing, a seal assembly with a metal seal sleeve having downwardly extending fingers, an internal metal annular bulbous sealing surface and an external metal cylindrical sealing surface, means for latching said seal sleeve in sealing position, a protector sleeve and means for releasably securing said protector sleeve to said seal assembly and said latching means, the latching means including retaining means preventing premature setting or movement of the latching means prior to the setting of said sealing means.

Abstract: A coupling assembly for detachably connecting a pair of wellhead members, includes couplable first and second coupling members. Each coupling member has a central axial bore for accommodating a drill string, and each coupling member is adapted for axially aligned connection to a wellhead member. The first coupling member is axially rotatable relative to the second coupling member, into locking engagement therewith. The coupling also includes sealing means disposed between the coupling members, and means for rotating the first member relative to the second member.

Abstract: The present invention relates to an improved subsea wellhead structure which includes a conductor casing having an internal upwardly facing shoulder, and an internal groove above the shoulder, an external groove, a wellhead housing having an external downwardly facing shoulder adapted to seat on the casing shoulder, an external shoulder above the seat shoulder which tapers upwardly and outwardly at a slight angle, such as, for example, five degrees, a split latching and loading ring surrounding said housing and seated on said tapered external shoulder, a cam ring above the split ring, means for releasably retaining the cam ring in its inactive position and actuating means for moving the cam ring into position wedging the split ring outwardly on the tapered shoulder into tight load transmitting position within the internal casing groove and the tapered shoulder.

Abstract: An improvement in an offshore well having a main casing penetrating subterranean formations below the bottom of the water and protruding upwardly through the water with a wellhead affixed above the surface of the water and a boat landing connected with the main casing. The improvement comprises a plurality of at least three anchor piles driven into the bottom at respective azimuths and distances about the well with the well anchored thereto via cables, the cables running upwardly through pulleys disposed a predetermined distance, such as 15 feet, below the surface of the water so as to anchor the well against lateral forces, yet satisfy Marine Maritime Service regulations and allow maneuvering of boats about the well. Also disclosed are typical and preferred structures including sizes and the like.

Abstract: An improvement in a subsea wellhead apparatus that includes the conventional plurality of strings of conduit suspended in a borehole penetrating subterranean formations below the bottom of a sea at which the wellhead apparatus will be placed and the conventional wellhead and accessories disposed above the bottom and the plurality of strings of conduit; the improvement comprising a first communications aperture communicating with a first annular space intermediate a desired pair of conduit strings; a sealed conduit that defines a sealed path of flow for flowing a fluid waste into the annulus intermediate the respective conduit strings; remotely operable high pressure control valves interposed in the conduit for controlling the flow of fluid between the annular spaces and a remote control for controlling the flow control valves so as to route the fluid waste to the first annular space and fractured formation communicating therewith.

Abstract: A method and apparatus is disclosed for controlling a well drilled from a floating drilling vessel during the time that the marine riser is removed and conductor casing is being lowered and cemented into the well. An annular blowout preventer having a bore substantially equal to that of the structural casing is provided in a stack above the structural casing wellhead housing. A kill line is provided to the drilling vessel and is connected to the wellbore conduit below the blowout preventer. A marine riser is attached to the top of the blowout preventer through which the hole to be lined with conductor casing is drilled. The well is established to a depth of about one thousand (1000) feet below the seabed.The annular blowout preventer is closed, the marine riser is removed, and a stripper and guidance assembly is landed on the top of the blowout preventer in preparation for lowering the conductor casing in the well.

Abstract: A subsea drilling and production system where the production unit is removably connected onto a drilling template and operatively connected to one or more Christmas trees so that the production unit may be disconnected from the trees and removed from the template without first removing any of the trees and so that any of the trees may be disconnected from the production unit and removed from the underwater site without removing the production unit.

Abstract: A system for connecting an exploratory well into a producing well by retrieving a permanent guide base (P) and replacing the same with a completion guide base (C) containing the necessary equipment for producing from the well. To do this, the permanent guide base comprises two parts; a gimbal part (32) and a platform part (34)--the platform part (34) can be detached from the low pressure wellhead housing (W) and retrieved leaving the wellhead housing (W) and the permanent guide base gimbal part (32) subsea. The wellhead housing (W), provided with a latching profile (154), though not used during exploratory drilling, is now used to latch the completion guide base (C) thereto for production from the well. The two parts of the retrievable permanent guide base are latched together by a latching mechanism (74) which is easily releasable to unlatch one part from the other, and both guide bases (P & C) are provided with wire line guide posts (82) which are easily detachable for replacement if necessary.

Abstract: Disclosed is a manifold control system 80 for a completion tree 10 comprising a manifold plate 92 having a plurality of single port or multi-port two position spring biased piston type valve cartridges 82 mounted thereon, which individually route hydraulic control signals to the various valve and connector operators 14,18 and 30. The two position spring biased piston type valve cartridge thus performs the function of a tree cap and eliminating the need for the latter, and thus eliminating running/retrieval operations required for tree closure and control hook up during installation workover and retrieval. These valve cartridges are detachably connected to the plate and may be replaced, whole or in part, subsea; their number and type selectable according to the needs of the tree; in a workover mode cooperate with a running tool and in a production mode automatically close the cartridges and control lines to seawater, debris and the like.

Abstract: A control system (10) employable for purposes of effecting the operation of a plurality of actuable devices, which are located at a subsea site, from a position that is remote therefrom. More specifically, the subject control system (10) is particularly suited for employment for purposes of hydraulically effecting the operation of the valves of a subsea christmas tree (30). To this end, the subject control system (10), on the one hand, is connected in fluid flow relation with a surface control center (16) from which hydraulic fluid is supplied under pressure, and, on the other hand, is connected to a subsea sequence valving means (12) which receives the hydraulic fluid under pressure from the surface control center (16) and in turn transmits hydraulic power to the operators (46, 48, 50, 52, 54, 56) of the christmas tree valves to cause the latter to move in accordance with a predetermined operating program (32).

Abstract: A wellhead connector assembly for use on undersea template platform where a plurality of wellheads are connected to a center work enclosure hull having a plurality of penetration connectors projecting from its sidewall. The present assembly has a connector for fitting on the wellhead, and a laterally movable connector for coupling with a penetration connector. A vertical actuation rod pivots a bell crank linked to the connector to cause lateral movement thereof. A loop of pipe connects the wellhead to the laterally movable connector and biases it to a neutral position.

Abstract: A sub-sea well assembly has features to eliminate side-to-side movement between a wellhead and a wellhead housing due to movement of the drilling vessel. The wellhead extends into the wellhead housing and is connected on its upper end to equipment extending to the vessel. Slips are located in an annular space between the wellhead housing passage and the exterior wall of the wellhead. The slips are mounted so that they will slide from the contracted position when the wellhead is being placed into the wellhead housing to an expanded position after the wellhead is locked into the wellhead housing. In the expanded position, the slips move downward to wedge, but are not weight bearing. The slips are self-actuating, with a spring to urge them downward into the expanded position.

Abstract: A control system (10) employable for purposes of effecting the operation of a plurality of actuable devices, which are located at a subsea site, from a position that is remote therefrom. More specifically, the subject control system (10) is particularly suited for employment for purposes of hydraulically effecting the operation of the valves of a subsea christmas tree (30). To this end, the subject control system (10), on the one hand, is connected in fluid flow relation with a surface control center (16) from whence hydraulic fluid is supplied under pressure, and, on the other hand, is connected to a subsea sequence valving means (12) which receives the hydraulic fluid under pressure from the surface control center (16) and in turn transmits hydraulic power to the operators (46, 48, 50, 52, 54, 56) of the christmas tree valves to cause the latter to move in accordance with a predetermined operating program (32).

Abstract: A subsea wellhead assembly for areas subject to iceberg scouring including an upper conductor in a well bore and a lower conductor in the well bore with the upper end of the lower conductor being within the lower end of the upper conductor and connected thereto by a weak connection and the upper end of the lower conductor being below the maximum iceberg scour depth and means for connecting said conductors, said connecting means having sufficient strength to withstand bending loads during drilling and being removable for installation of production equipment.

Abstract: A subsea well assembly has features that allow a riser string leading to the surface to be purged of well fluids prior to pulling the riser string. The well assembly includes a riser connector that seats on a Christmas tree. The Christmas tree and connector have coaxial bores, the ends of which are separated from each by a chamber. A stinger interconnects the bores and extends through the chamber. The stinger has upper and lower pressure shoulders. Hydraulic fluid pressure applied to the lower shoulder causes the stinger to retract from the Christmas tree bore. This allows communication of the connector bore with an annulus passage also located in the connector bore. Fluid can then be pumped down the annulus passage to flow through the chamber and return up the connector bore, purging the riser of well fluid.

Abstract: A completion system or tree system for a subsea well having an anchor base on bottom surrounding a well bore, a conductor pipe lining the upper end of the well bore and connecting to the anchor base, a guide base landed on the anchor base and having an upwardly facing funnel positioned in the opening of the anchor base, and a production string extending through the conductor pipe and bending to a substantially horizontal position slightly above the guide base with the start of its gradual bend being below the funnel and with sharp bend production tubing bending immediately avove the funnel since no high profile guide base is present on the anchor base.

Abstract: A flexible connection apparatus is disclosed for accommodating relative movement between a compliant offshore structure and the sea floor. The compliant offshore structure supports a fluid-carrying system which conveys fluids between the sea floor and the structure. The fluid-carrying system includes a riser and a helical flowline. The lower end of the riser is connected to the sea floor. The first end of the helical flowline is connected to the upper end of the riser and the second end of the helical flowline is connected to the structure. As the compliant offshore structure is displaced from its vertical equilibrium position due to loading forces induced by wind, waves, and ocean currents, the helical flowline elastically flexes through torsional deflection to accommodate such movement. In a preferred embodiment of the apparatus, a wellhead is connected between the riser and the helical flowline such that the centerline of the helical flowline is substantially vertical.

Abstract: A subsea well completion system, and components of such a system, are disclosed for handling marine well fluids from multiple subsea wells.

Abstract: An apparatus and method for drilling and completing a subsea well located at the seabed using a retrievable piping deck. The apparatus includes a template supported on the seabed, the retrievable piping deck supported on the template, a plurality of wellheads supported on the template and a plurality of Christmas trees supported on the wellheads. The piping deck has preinstalled flow lines and hydraulic lines to conduct well fluid from the Christmas trees to the surface and to conduct hydraulic control fluid from the surface to the trees. In addition to the Christmas trees, a well fluid manifold and a gaseous-liquid component separator can be supported on the template. The fluid connections between the Christmas trees and the hydraulic and flow lines and between the manifold and separator and the hydraulic and flow lines are accomplished by vertically oriented stab-in connectors.

Abstract: A subsea wellhead connection assembly for establishing fluid communication and production capability between a subsea wellhead and an adjacent subsea manifold system.

Abstract: A method and apparatus for remotely establishing an underwater well under conditions of great water depth including a drilling guide structure located on the floor of the body of water; a single handling and guiding string extending upwardly from the drilling guide structure and maintained in tension by an elongated buoy; a series of drilling guide arm units, flowline guide arm units and wellhead guide arm units to be lowered down the string, oriented relative to desired well positions and then retrieved once the wells have been drilled and the wellheads and flowlines secured in place; and a production gathering assembly to be lowered down the string, oriented relative to the wellheads and flowlines, and then coupled to these wellheads and flowlines.

Abstract: A wellhead (16) for an exploratory well carries a latch profile ring (24) at a location just above the wellhead housing (14). Accessory modules (38) latch onto this profile (36) while leaving the conventional upper latch profile (28) free for conventional production equipment. The accessory module may carry flowline alignment apparatus (40) to use the exploratory well as a satellite well. It may carry cantilever well modules (70) to permit the drilling of adjacent wells or a retrievable guide pile module (43) to provide placement of a guide pile required for proper placing of a jacket for an offshore platform.

Abstract: Method and apparatus for remotely controlling subsea template production systems having a plurality of satellite wells and a plurality of subsea trees on the well templates uses a significantly reduced number of electrical and hydraulic lines between a surface control unit and a riser base on the seafloor. An electrohydraulic control module on the riser base receives electrical control signals and provides hydraulic output signals to operate the riser base. Electrohydraulic control modules on the templates receive electrical control signals and provide hydraulic output signals to control operation of the trees on the templates. The satellite wells are each controlled by a single hydraulic signal line connected between the surface control unit and a matrix switching control module at the satellite well. All of the electrohydraulic modules are replaceable using surface operated running tools.

Abstract: Apparatus for controlling and preventing an oil blowout comprising a hollow frustoconical dome which is disposable over the end of a well discharge pipe or an offshore rig discharge pipe. At the top of the hollow dome is an axially disposed main valve for the blowoff of oil or gas escaping from the discharge pipe. A plurality of concentrically disposed two-way valves are disposed at the top of the dome about the main valve. With the main valve and the concentrically disposed valves open for the blow off of liquids and fluids, the dome is lowered over the discharge pipe. When the dome is fully lowered, it seats on the bottom surface surrounding the outlet of the discharge pipe. Concrete is poured around the dome to seal the dome to the bottom surface. Connected to the concentrically disposed valves are conduits for conducting gas and oil escaping from the discharge pipe to a storage facility, such as a barge, tank or the like, when the concentrically disposed valves are open for storing oil or gas.

Abstract: A through the flowline or "TFL" tool selector has a base provided with a number of spaced flowline ports and a diverter tube shiftably mounted in a housing for selective communication with the flowline ports. The base is mounted on a remotely operable connector, and the assembly is lowered onto a template beneath the sea having conduits aligned with the selector ports when the assembly is connected to the template. The inlet conduit loop of the selector assembly is also connected to an inlet conduit on the template. The connector is remotely operated to mechanically lock the selector apparatus in place.

Abstract: In a production well-head for an underwater oil well the suspension head of the innermost tubing, which has a frusto conical surface on which the production tube suspension member seats, has a duct leading from the enclosed space between the innermost tubing and the tubing adjacent thereto, to the interior of the innermost tubing, and a duct communicating therewith is provided in the suspension member.

Abstract: Method and apparatus for protecting subsea wellheads and christmas trees from damage by anchors, fishing nets, trawl boards, and other towed devices. The apparatus includes an annular, rigid protective enclosure with inner and outer walls that define a hollow annular chamber, and a plurality of bag-like containers spaced around and attached to the enclosure's outer wall. The annular chamber is in communication with the interiors of the containers by means of ports through the enclosure's outer wall, whereby when cement is pumped into the chamber it also flows into and fills the containers to form a smoothly contoured shield around the enclosure. Should an anchor or other device become fouled on this shield, the container or containers involved will break away and let the anchor continue on its way up and over the enclosure without damage to the wellhead or other well equipment.

Abstract: A plurality of members such as riser pipes are linked by means of a plurality of cylinders to a frame to which tension is to be applied. Each member is linked to the frame by a separate cylinder and the cylinders are interconnected so that the hydraulic fluid pressures in the cylinders are in a fixed proportion relative to one another.

Abstract: A system for controlling a plurality of subsea wellhead operators provides a dual set of operator controls having an electrical control cable and a pair of hydraulic control lines from the wellhead to a control center at the surface of the water. A primary set of electro-hydraulic multiplexed controls and a back-up set of hydraulic controls are each mounted in a separate control module on a base near the Christmas tree. When the primary set of controls fails operation is changed to the back-up set of controls by a signal from the surface control center. Defective control modules can be changed without removal of the tree cap as the controls are all outside the Christmas tree. Also, a defective primary control module can be removed while the back-up control module continues to control the operators in the Christmas tree.

Abstract: A system and method are disclosed which eliminates the use of a riser pipe in underwater drilling operations. The system includes a mud sump connectable to the top of a submerged wellhead and has a bottom with a mud inlet provided therein and an upwardly extending wall cooperating with the bottom to support a quantity of mud, the sump restricting the water to contact with only the upper surface of the mud as the mud passes upwardly through the mud inlet in the bottom. A hose, separate from the drill string, is used to carry mud to the surface of the water. A pumping means is used to pump mud through the hose in response to the quantity of mud supported within the sump to thereby return the mud to the surface of the water without the use of a riser pipe.

Abstract: An underwater Christmas tree for controlling flow from an offshore well is disclosed as having a master valve which is controlled by fluid pressure within a flow-line extending from a production bore of the tree, and means for receiving and releasably retaining a TFL tool in the production bore intermediate the location at which control pressure is sensed and the intersection of the production bore with an auxiliary bore of the tree through which wireline tools are run. Since the TFL tool limits flow therepast, flowline pressure may be maintained at a level necessary to maintain the master valve open independently of fluid pressure within the auxiliary bore.

Abstract: A well system and method of installation and operation for two-way communication between a service facility and a remotely located well head such as associated with an offshore well for such well functions as production of well fluids by gas lift. The system includes a well having a string of production tubing in a casing defining an annulus around the tubing, a gas lift valve in the tubing to admit lift gas from the annulus to the bore of the tubing to assist in raising production fluids to the surface, a well head including fittings for fluid communication into the production tubing and into the annulus, a service facility spaced from the well head including facilities for receiving well production and for pumping injection gas for gas lift in the well, and conductors communicating the service facility with the well head.