Patent ID: 9121529
Filing Date: 2015-09-01
Classification: F16L

Abstract:
1. A method of laying a hybrid pipeline comprising a rigid pipe section that lies on the seabed and a flexible jumper which is connected to the rigid pipe section, comprising the steps of: (i) lowering a rigid pipe section onto the seabed, (ii) raising one end of the rigid pipe section on the seabed to the surface of the sea, while leaving a portion of the rigid pipe section on the seabed, (iii) connecting one end of a flexible jumper to the raised end of the rigid pipe section so that the flexible jumper and the rigid pipe section are in fluid communication, and (iv) lowering the one end of the flexible jumper to the seabed with the raised one end of the rigid pipe section attached, to return the raised one end of the rigid pipe section to the seabed and to lay the flexible jumper on the seabed, wherein a connection between the raised one end of the rigid pipe section and the flexible jumper receives auxiliary support from an abandonment and recovery winch and winch line on a flexible lay vessel used for deployment of the flexible jumper, when the one end of the or each flexible jumper is lowered to the seabed with the respective raised one end of the rigid pipe section attached, to return the raised one end of the rigid pipe section to the seabed and thereby maintaining a sufficient bending radius in the flexible jumper greater than a minimum bend radius of the flexible jumper.