Case History: Well Completion and Servicing Strategies for the Hibernia Field

Abstract

Offshore field development includes not only planning for appropriate well completion designs but also implementation in such a manner that production and economic goals for all stakeholders are realized. Consideration must also be given to operational support functions so that their administration will meet the project needs without compromising environmental, regulatory or safety standards. Often, a multidiscipline team approach offers the best method for developing the solutions needed to accomplish all the objectives. In this paper, Hibernia Management's approach to well development, completion and servicing strategies are discussed. Initial completion strategies were required to meet the designated design criteria of maximum well deliverability, minimal well maintenance, well servicing costs, and finally, minimal overall field-life-cycle costs. To comply with these stringent requirements as well as future needs, the downhole configuration would have to facilitate future non-rig workovers, recompletions or redrills, and have the flexibility to allow incorporation of future technological advances or changes in reservoir management. In reviewing all options, minimizing overall field-lifecycle costs and the number of potential workovers were to be given primary consideration. Also of significant importance was the need to provide a zonal recompletion method as it was felt that the need for selective isolation of different zones would be needed to maximize recovery throughout the life of the wells. Completion strategies, the completion configuration, pre-installation shop tests, personnel training, completion servicing considerations and other challenges such as a "green field site" and rig requirements were reviewed; from these analyses, operational strategies were developed. The initial completion installations were successful. The first two wells flowed approximately 40,000 BOPD and are Canada's highest producing wells recorded to date! Introduction The Hibernia Field is located in the North Atlantic Ocean, approximately 315 km east/southeast of St. John's Newfoundland in approximately 80 meters of water. It is estimated to contain 3 billion barrels of crude oil, of which 615 million barrels are expected to be recovered. Average daily production from the gravity-based platform is expected to plateau at 135,000 BOPD, and field life is anticipated to exceed 20 years from the initial production start up date- November 17, 1997. Fig. 1 is a map of the Hibernia field location and Fig. 2 is a photograph of the Hibernia Platform.. The majority of reserves within the Hibernia field are found in two principal formations: the Hibernia sandstone at approximately 3700 meters subsea, and the Avalon sandstone at approximately 2400 meters subsea. The Hibernia sands will be developed first since they are of higher reservoir quality. Fifty five completions are planned. Twenty five are scheduled for the Avalon over field life. The majority of the wells will be drilled and completed during the initial years of field development with 64 wells targeted for completion by 2003. Due to the project scope, this paper will focus its discussion on the hardware for the completion configurations and how completion equipment was selected by the multidisciplined team1.2.3 to address project strategies. While the authors realize that drilling and completion fluids and perforating are integral parts of the completion and provide major contributions to its success, these topics are outside the scope of this paper.

Field Data Supports the Use of Stiffness and Tortuosity in Solving Complex Well Design Problems

“…The Hibernia field was discovered in 1979 and is one of the largest known oilfields in North America with an estimated two billion barrels of oil in place, of which 615 million are conservatively estimated as recoverable, [9]. The current owners in the field are Chevron, Mobil, Murphy Oil, Norsk-Hydro, Petro-Canada and the Canada-Hibernia Holding Company.…”

Considerations for the Design, Development, and Testing of an Integrated Large Monobore Completion System to Facilitate High-Rate Production

“…To this end, newly developed concepts in monobore completion techniques are receiving more consideration as a possible method for resolving these challenges. 1,2,3,4 The integrated completion system described in this paper is designed to minimize wellbore complexity, increase completion reliability, and provide the remedial flexibility necessary to exploit a high-rate reservoir to the fullest extent.…”