The Planning and Drilling of a Wildcat Well in the Republic of Seychelles by an Operator-Contractor-Integrated Services Alliance

Abstract

Constant Bank - 1 is a 3,200m (10,500ft) wildcat well located in 50m (164ft) of water on a carbonate bank in the Republic of Seychelles, a group of tropical islands in the Indian Ocean. This paper covers in detail how the contracting philosophy was developed to plan and execute the project through the formation of an alliance comprised of Operator, Drilling Contractor and Integrated Services Company. It examines the unique environmental and logistical features of this project and how the alliance sought to deal with these critical issues utilising the strengths of the respective companies to reduce risks and ensure a cost-effective, successful operation, The logistical management of planning a rank wildcat in a remote location with no practical means of resupply and no local resources was further complicated by anticipated technical difficulties with the well. The paper concludes by considering the different objectives of each company in conjunction with the overall project objectives and how these respective goals were aligned to the mutual needs of the alliance. The lessons learned by all three alliance members are noted and recommendations made on how they would approach such all operation in the future. Introduction Enterprise Oil Exploration Ltd., under a license agreement with the Seychelles National Oil Company, had a commitment to drill a subsea exploration well to a total vertical depth of 3,200m (10,500ft). The well was located on Constant Bank, 200 km (124mi) south east of the main island of Mahe (Fig. 1). Enterprise was the sole licensee with 100% equity in the well. This paper describes the various factors that increased the risks and consequently the potential costs of drilling this well. A project management strategy involving integrating all the principal services into two distinct contract groups was devised and applied to manage these risks and reduce the costs. The lessons learned from the application of this process to a high-risk remote-location single-string venture are noted and recommendations are made for enhancing this form of management strategy in future drilling operations. In addition, the limitations of this type of approach are defined. Project Outline The principal factor governing the drilling project is the well location. Located in 50m (164ft) of water on a carbonate bank 200 km2 (124mi) from the main island of Mahe and over 5,300km (3,300 mi) from the Singapore supply base, the well had a number of significant risks associated with it. The Republic of Seychelles is one of the smallest countries in the world with a population of 70,000 people living on several small granite islands totaling 280 km2 (175 mi2) in area in the western Indian Ocean. The country is renowned for its unspoiled, pristine environment with the main sources of revenue being tourism and fishing, two businesses that are usually not associated with oil exploration. These potential incompatibilities could be compounded by the company's very high public exposure in such a small country. Consequently, environmental protection was of paramount importance. Moreover, the country was devoid of any infrastructure to support an offshore exploration programme. Coupled with this, the remote location of both the well and the islands themselves meant that any resupply would be very difficult unless by air. This combination of these geographical and ecological factors resulted in the decision to use a drillship. The vessel to be selected had to have the capacity to carry all the equipment and materials for the well plus considerable contingency. Added to all the aforementioned challenges, the well was a rank wildcat and given the difficulties of resupply it would be necessary to carry substantial additional materials to allow for any unforeseen well problems. Also, the drillship would require state-of-the-art minimum-discharge systems to meet the onerous environmental restrictions imposed by the Seychelles authorities. P. 431