The Bullwinkle Project: An Overview

Abstract

ABSTRACT The Bullwinkle platform is located in Green Canyon area, Gulf of Mexico in 1353 feet of water. It is the largest steel offshore platform in the world, located in the deepest water and is taller than the world's highest building. The platform took five years to design, build and install. Seventy-five thousand tons of steel were used to build this structure, of which 49,000 tons were in the jacket, 13,000 in the conductors, 11,000 in the piling and 2,000 in the deck. This paper discusses the planning, phased bid/award and schedule control and gives a broad overview of the building and installation process. Several companion. Papers (1-11), give specific details of the platform design and construction. INTRODUCTION In May 1983, Shell Offshore Inc. (SOl) acquired Blocks 65 and 109, Green Canyon area, for a lease bonus of $30.1MM. In April 1984, Block 64 was acquired for an additional $4.4MM. The leases on all three blocks are 100% owned by SOl. This prospect area (Fig. 1) was code named Bullwinkle by SOl's explorationists, a name that continued throughout development. The discovery well was drilled in October 1983 on Green Canyon Block 65. A total of four wells and four sidetracks were drilled in the three blocks to evaluate and delineate the reservoirs. Evaluation of development alternatives had been underway concurrent with field exploration, and in June 1985 construction of a platform was begun in accordance with the schedule shown in Fig. 2. Platform installation was completed in late September 1988. The basic characteristics of the platform are described in detail in companion papers (1-11), but Fig. 3 provides some basic information on forces, weights and dimensions. Development drilling is presently underway, with initial production scheduled to begin in 1989 while drilling continues. Oil production is expected to peak at 50,000 barrels per day, with natural gas production reaching 90 million cubic feet per day in 1992. The Bu11wink1e project will cost about $500MM excluding lease bonus costs. About 50% of the project costs was spent to build and install the platform. The other 50% will be spent for development drilling, permanent production facilities and a pipeline system. PLANNING Various concepts for field development received consideration during the early engineering efforts. These included (i) two fixed platforms, each With 24 well slots; (ii) one fixed platform with 50 slots; (iii) a compliant tower. Based on in-house estimates of project costs the single fixed platform, with capability to handle two drilling rigs and 60 wells, was chosen. The project schedule noted in Fig. 2 was developed with an early June 1988 target date for launch. That launch time was chosen to avoid the spring weather, and to allow sufficient time for offshore work before the major part of the hurricane season. Figure 4 dramatically shows the statistical .significance of working offshore early in the hurricane season.