Four Years' Experience Operations - MSV

ABSTRACT This report presents the operating experience of Multi-Functional Support Vessels (MSV's) which have been put in service to meet the needs of specific offshore areas. The offshore petroleum industry started in the 1960's equipping offshore vessels with special equipment to support offshore operations. This equipment includes fire fighting, wild well control, platform evacuation, diving inspection, pipeline/platform maintenance, and hotel/field storage facilities. In the mid-1970's the industry determined that special vessels were required to effectively utilize this particular equipment and provide year-aroun4 service. Several special vessels have been committed, built and put in service. The operating experience of these vessels for daily and emergency assignments has proven these units have justified the costs and commitments. INTRODUCTION In the early 1950's, 1960's and 1970's there were no special vessels assigned to and justified to support continuous daily maintenance and emergency support for a specific producing area. Industry depended upon the use of existing vessels on which special equipment was installed for the specific maintenance or emergency. Conventional barge-type derrick barges were the most frequently used units; however, the time required to mobilize this equipment and its efficiency in weather environments was not effective overall. Figure 1 shows the types of equipment spreads that were used in the past to control offshore platform fires. In the 1970's it was determined that existing equipment and techniques could not efficiently be used to combat offshore petroleum emergencies. Platform costs, water depth, and rough sea conditions of the North Sea were the final convincing factor. Figure 2 illustrates the specialized Multi-Functional Support Vessels that were developed to meet the industry's needs. The MSV had two justifications. First, it was equipped and ready to fight the offshore emergency, and secondly its daily use as a field maintenance vessel. Listed below are examples of the MSV's daily and emergency functions. Justification 1. Daily Work - Field Service Diving Inspection Platform Maintenance Floating Machine Shop Production Equipment Repair Pipeline Repair Field Storage Hotel Service Sub sea Well Maintenance 2. Emergency Work Evacuation Platform Hospital Helicopter Base Fire Control Wild Well Control Pollution Pickup One MSV can serve several platforms or fields for both of the above justifications. There are several types of MSV's and several joint industry efforts between oil companies and countries that have justified the services of MSV's. This paper will present some of the history, give examples of joint efforts, describe some of the MSV vessels, and report on the operating experience of one of these semi-submersible vessels. HISTORY Field maintenance vessels used in the past have been contracted on an "as needed" basis. Derrick or pipe lay barges were the primary source of maintenance units. These units had hotel, crane, storage and other support facilities for repairing items offshore. This same equipment was used to fight offshore emergencies. An example of the use of conventional equipment to fight an offshore blowout is given in Figure 3. The methods used conventional equipment to set a platform beside the burning structure and the fire fighting operations were conducted from this platform.