A New Approach to Capex and Opex Reduction: An Integrated System for Remote Tie-Ins and Pipeline Repair

Abstract

Abstract The industry move towards deep water is constantly demanding for the development of new and innovative technologies, as well as reduction in costs, to let most of the new reservoir discoveries to be financially attractive. As a result, the demand for designs, which could led to savings in both CAPEX and OPEX is steadily increasing. As part of their continuos growth, Sonsub International has developed and tested a new system (Brutus) dedicated to the remote tie-in of rigid lines in large water depth. The main design parameters are that it operates to 3000 meters water depth, handles up to 24" diameter pipe and is capable of connecting pipe by using flanges, clamp or collect connectors - as well as special connectors such as Morgrip. The system will be used during summer 2000 to perform diverless tie-ins of a 16" pipeline and, prior to this, a complete set of shallow water trials will be carried out. Furthermore, the system has also been proposed as a pipeline repair system, due to its working philosophy and Sonsub's knowledge and experience within this field (DSRS - Diverless Sealine Repair System). This paper will briefly introduce the Brutus system and present the result of the wet trials. Also, the system's pipeline repair capabilities and methodology will be outlined. Consideration about the integrated approach and its advantages with respect CAPEX and OPEX will be given, together with a general analysis comparing the benefit of this concept versus existing tie-ins and/or repair systems. Introduction The possibility of utilizing a common system during the completion of a field (CAPEX) and also during its lifetime (OPEX) is a very interesting option, especially for medium/deep waters developments requiring innovative and diverless technology. Having a large experience in both remote connection technology and repair of either rigid or flexible lines, Sonsub felt that a common approach to both the above topics would be a major step towards cost saving and standardization of equipment for deep water field developments. As a result of the above, and following the development of both the DSRS (Ref. 1) and the BRUTUS system (refs. 2 & 3), Sonsub has now developed a new concept. The concept is based on the combination of the above systems and will allow Sonsub to offer a single approach to tie-in and repair operations with proven diverless technology. The DSRS Background The DSRS is a development of the original Pipeline Repair System (PRS), first tested in 1992. A succession of shallow water trials of the various subsystems has allowed optimization of the individual and overall designs. The final solution is now a "low force" modular concept, which offers the following benefits:It is independent of surface equipment;Low force;In the event of bad weather, the ROV can be recovered and the site temporarily abandoned;Operates using readily available work class ROVs;Can be deployed rapidly from a ROV support vessel;