Geology

Hammer

Firth

Operations research

Structural engineering

Schedule

Operating system

Construction engineering

Oceanography

Engineering

Submarine pipeline

Principal (computer security)

Marine engineering

Systems engineering

Geotechnical engineering

Towing

Computer science

Underwater

ABSTRACT This paper reviews the Planning and execution of the Marine Operations for the Hutton TLP including:Well Template InstallationSite PreparationFoundation InstallationTemporary AnchoragesMatingMajor TowsTLP Installation Planning the work to meet project objectives resulted in the utilisation of a number of new techniques and advanced equipment applications. These included underwater pile hammers and special acoustic equipment to provide positioning information during underwater operations. However, the detailed planning which preceded each operation significantly enhanced the effectiveness of the equipment employed. Further, it contributed materially to the attainment of First Oil only twenty two days after TLP installation. INTRODUCTION The 'towing, mating and installation of the Hutton Tension Leg Platform (TLP) involved extensive marine operations ranging from conventional sea tows to the first-ever installation of a TLP. To ensure the success of some of the more complex marine operations, special methods and unique equipment applications were required. A number of these are addressed in papers presented at other OTC sessions. This paper provides an overview of all of the principal marine operations associated with the TLP, highlighting those which required something more than a conventional approach. Figure 1 shows the relative locations of the operations covered, including:Hutton Field, Offshore OperationsInshore OperationsInverness Firth AnchorageMoray Firth AnchorageHull T?OWDeck TowMating The paper stresses the importance of effective management in the success of marine operations including the specific areas of advanced planning, contingency planning, co-ordination with regulatory agencies and the supervision of contractors. The overall marine operations schedule is included as Figure 2. Marine Operations on the project critical path were the Hull Tow, Mating, TLP Tow and Installation. WELL TEMPLATE INSTALLATION A 32 slot template for pre-drilling wells (Figure 3) was the first structure to be placed at Hutton. The template, measuring 33.2m long by 11.6m wide by 6.6m high and weighing 400T in air, was installed in two phases: Phase 1 In April 7981 the template was transported to the field and within 24 hours of arrival at Hutton was placed on the sea bed. The template?s final position was within 5.Om of the geographic target. This accuracy was achieved by using a newly developed subsurface acoustic positioning system integrated with surface electronic navigation equipment. The subsurface equipment was developed from an existing transponder which operated in a short base line mode and transmitted data on position, orientation and levelness. This system became an integral part of the systems developed for foundation and TLP tether leg installation. Phase 2 A semi-submersible drill rig was used to complete the template installation.

Hutton TLP Marine Operations