Abstract: A shallow water flow subsea drilling system is disclosed. A wellhead system is provided with a 36″ conductor pipe in which a 26″ casing and 26″ wellhead housing are landed. The 26″ casing extends to a depth above a shallow water flow zone. A borehole through the shallow water flow zone is sized to accept a 20″ casing to the top of which is secured an 18¾″ wellhead housing. An annulus between the 26″ and 18¾″ housings communicates with cement returns from the 20″ casing. Flow-by holes in the 26″ wellhead housing are sealed with a retrievable seal assembly and actuating mechanism run on the same running tool with the 20″ casing and 18¾″ wellhead housing. A hydraulic feedback mechanism is provided to sense at the service vessel whether or not the seal assembly has been correctly positioned in the annulus.

Abstract: A radially locked subsea housing includes a low pressure housing having upper and lower radial lock regions, each of which regions includes a radial interference surface that is between vertical to only slightly tapered in orientation. A high pressure housing also has upper and lower radial lock regions, each of which regions includes a radial interference surface that is slightly greater in radial diameter than the corresponding interference surface of the low pressure housing. The interference surfaces of the upper and lower radial lock regions form upper and lower interference fits, respectively, between the high pressure and low pressure housings when the housings are assembled subsea.

Abstract: A subsea wellhead tieback connector actuated solely by axial motion to achieve connection to and disconnection from the wellhead. The connector includes interconnected inner and outer bodies, a split lock ring surrounding the inner body, and an energizing mandrel for non-rotary axial movement to expand the lock ring into engagement with a wellhead component.

Abstract: A protective cap (12) can be run onto and retrieved from a subsea wellhead (10) from a floating service vessel. Slidably mounted shear pins (32) in the cylindrical wall (14) of the protective cap (12) allow the cap to be attached by a downward push. Retrieval of the protective cap (12) involves an overpull on the drill string that is sufficient to shear the pins (32) in the cylindrical wall (14).

Abstract: A running tool for lowering, landing and setting a well structure, such as casing hanger and a packoff has an elongated tubular body in which are mounted a plurality of locking dogs that releasably lock a casing hanger to the tool, a plurality of packoff running pins for releasably locking a packoff to the tool, and a plurality of packoff retrieval pins to engage a packoff in a wellhead housing and secure it to the tool for retrieval from the housing. The locking dogs are cammed radially from the tool body into their hanger engaging position by an actuator sleeve, and the running pins and retrieval pins are spring-biased in a radial direction towards their packoff engaging positions and releasably held in their retracted positions by retraction shafts in the tool body.

Abstract: A running tool for use with a subsea well guide base when drilling from a floating drill ship is designed to be releasably detached without rotation so that the tool can be uncoupled at the surface upon completion of the guide base running procedure. The running tool is attached to the guide base by threaded elements which are designed to strip when a predetermined upward force is exerted on the running pipe string to which the tool is integrally connected thereby permitting retrieval of the tool by the running string.

Abstract: A retrievable guide base and gimbal unit for a subsea well, and a tool for use with a pipe running to retrieve the guide base and gimbal from the subsea wellhead.

Abstract: A well casing hanger/packoff apparatus with ports through which fluids can be circulated during installation and cementing operations, and a sleeve-type valve that can be moved axially to open or close the ports as desired.

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: Indicator valve unit for providing a change in fluid pressure as a remote indication of whether an object occupies a desired position. Particularly useful for indicating whether a component, such as a multiple string tubing hanger, has been properly oriented and landed in an underwater well installation, the indicator valve unit provides for automatic separation of the sensing element of the unit from the sensed object as soon as the valve has been actuated.

Abstract: Tool for giving remote indications, typically both a change in fluid pressure and a televised image, to check whether a device is in a desired position. The invention is particularly useful for checking whether a component, such as a pipe hanger, has been properly landed in an underwater well installation.