The laying and coupling of subsea flowline bundles is an important feature of subsea oil and gas production systems. A critical part of the operation is the final pull-in, alignment and connection of the flowline to fixed seabed production structures. This paper traces the development of equipment to accomplish the diverless connection of flowlines and control lines and the field experience to date.

The laying and coupling of subsea flowline bundles is an important feature of subsea oil and gas production systems. A critical part of the operation is the final pull-in, alignment and connection of the flowline to fixed seabed production structures. This paper traces the development of equipment to accomplish the diverless connection of flowlines and control lines and the field experience to date. lNTRODUClION A typical subsea production (or water injection) system consists of one or more seabed-installed Christmas Trees with flowlines and control lines communicating with a fixed platform or gathering manifold. It is necessary that these flowlines can be installed or replaced with the minimum of disturbance to the Christmas Trees or receiving structure. Flowline laying techniques are established to place a flowline end on the seabed with an accuracy of wi thin 100 ft. radius of target. This means that flowline laying equipment can be mobilised and the basic installation of the flowline finished before or after well operations are completed.Equally, a replacement flowline end can be deployed at the seabed within 100 ft. or so of ~ producing installation with the minimum risk of damage.Once the flowline has been laid, critical operations remain in:1Pulling in the final distance.