Constructors John Brown Limited

Bechtel Corporation

The British National Oil Corporation

John Brown Engineers and Constructors Ltd.

Keith Shotbolt

A flexible riser 10 has a lower connector 11 which is moved laterally over the seabed by a pull-in sled 7 under a mid-water support buoy 3 to connect it to a connection point 17 on subsea equipment 1. The riser 10 is attached at a point part way along its length to buoy 3. This is done at one side of the buoy prior to construction vessel 13 laying the riser over the buoy and connecting the upper connector 24 to a production vessel 2 positioned over the subsea equipment. Attachment is done by guiding the riser pipe into a channel 36, a projection 20 on the riser engaging the channel against lowering of the pipe. A upper connector of the riser may include a single pivotal arm and a single offset guide post to maintain its orientation while it is being pulled into engagement with a mating part on the production vessel.

Flexible riser system

A floatable oil/gas production platform assembly has a deck, disposed beneath the deck a zone including a plurality of adjacent stations for support of oil/gas flowlines/risers originating from beneath the platform, and a crane disposed in a space above the station zone but below the deck and moveable over at least some of the stations. Such an assembly enables two new alternative equipment arrangements to be provided in floating platforms for tensioning and supporting underwater well maintenance lines or 'workover risers' which require considerable tensioning forces and stroke capacity for safe support.

Crane assembly for floatable oil/gas production platforms

A connector assembly comprises first and second connecting parts which are oriented for joining by a guide post and a cable having a hydraulic hose core terminating in a radially expandable mandrel. The cable is threaded through a bore in the second connecting part and located in the bore of the guide post by a hydraulic latch. The cable is tensioned and the second connecting part slid along the cable to the receive guide post in the opening thus orienting the two connecting parts for proper connection.

Connector assembly

A guide is provided for forming a pipe connection from a sub sea wellhead back to a surface platform which may not be in perfect alignment. The guide comprises a guide post and a cable on which it may be lowered through a pipe to the wellhead. The guide post has a radially expandable mandrel for temporary rigid attachment in the wellhead and an elongate portion having a rotatable sleeve over which the pipe may be lowered into engagement with the wellhead and rotation to form the connection desired. The rotation of the pipe to form the connection is possible because of the sleeve.

Guides for use in forming pipe connections and a process of forming pipe

A guide for use in connecting a riser pipe to a subsea riser base comprises a guide post and an expanding mandrel actuable by hydraulic pressure applied through a cable having hydraulic hoses in its core to lock the mandrel in a subsea riser base. The guide post is provided with buoyancy means to reduce its effective weight in water to enable it to be manipulated and manoeuvred by a remote controlled vehicle or diver.

Guides for forming connections

A template for spacing a submarine structure such as an anchor block or a guide base for a second underwater well alongside an existing underwater well comprises a beam attached at one end, by means of a hinge, to a lowering guide which can be threaded over and be lowered along two guide wires of the first well, and at the other end by a remote-controlled release mechanism to the submarine structure such as the anchor block itself or a guide base for a second well. The beam, with such a submarine structure attached, is lowered down the guide wires while held in a vertical configuration, and is then swung into a generally horizontal configuration at the sea bed.

Growing community of inventors

Gerrards Cross, United Kingdom

Keith Shotbolt