A Truly Multi-Role-Vehicle

Abstract

ABSTRACT The design, manufacture and field operations of the MRP, a remotely operated vehicle, is discussed. This particular ROV is being extensively used throughout the world as a tool in the installation and maintenance of subsea equipment in the production of hydrocarbons and other supporting activities. The paper outlines the philosophy behind the design of this remotely operated vehicle and discusses both the technological and operational developments made from earlier systems and the advantages it has over other ROV systems. Field operation information, taken from the operations which the vehicles have performed since their purchase including detailsof operations to water depths in excess of nine hundred metres, are included. The possibilities for utilising such an ROV system in future offshore projects is also examined. INTRODUCTION Since the late nineteen seventies Subsea remotely operated vehicles (ROV's) have increasingly being used as tools to assist in the production of offshore hydrocarbons. Generally speaking ROV's have been categorised into two groups namely ‘inspection’ and ‘work class’. The main differences are:Their sizeTheir function Conversely, because of Health and Safety initiatives together with the relatively high operational costs associated with the hire of diving spreads, the industry has seen a steady decline in the use of professional diving teams. The majority of work class ROV's produced during this period were designed and manufactured primarily to perform specific tasks. For example the ‘Scorpio’ survey vehiclesand the ‘Trojan’ drill support vehicles. This meant that the ROV operators have had to purchase several different types of vehicle to allow them to offer a range of services to the industry. Accordingly the operators have to hold several differentspares packages to support the equipment, this in turn leads to higher operatingcosts all of which must be met by the industry. This paper outlines one ROV manufacturers approach to addressing this problem while combining what is believed to be the future needs of the industry. CONCEPT The MRVTM (Multi-Role-Vehicle) concept devolved from an extensive evaluation of the future requirements for work class remotelyoperated vehicles. This evaluation primarily consisted of discussions with the Oilcompanies and several ROV Operating companies. It became obvious that a vehicle which could perform a multitude of tasks preferably during the same operation would be advantageous. A vehicle which would be capable of carrying work-packages which conformed to industry ‘standards’ would ease the problems of availability and single source supply. A vehicle which could be used to perform several jobs during a singledive would of course lead to a saving of operational time and therefore money. As the name implies the Multi-Role-Vehicle is not just one vehicle but potentially anynumber built on the modular concept of a core vehicle to which specific workpackages are added only as necessary. The advantages with this approach are:Greater FlexibilityLower Capital costsLower Operating CostsShorter delivery lead times The concept of the vehicle can be aligned with that of an agricultural tractor to which trailers, buckets.