Reservoir Development Plan for the Terra Nova Field

Abstract

Abstract The Terra Nova Oilfield located offshore Newfoundland, Canada, is currently under development according to a subsea layout with 4 "drill" centres and a floating production storage and offloading (FPSO) vessel. First Oil is planned for mid 2001. The base case reservoir development requires a total of 24 development wells plus flexibility to develop additional upside potential. Reservoir flexibility management requires waterflood and gas injection capability. The options of changing to water-alternating-gas (WAG) later in field life as well as converting certain producers to injectors are also a feature of the reservoir management plan. The development plan requires that 6 wells be pre-drilled prior to the arrival of the FPSO vessel. Results from these wells have confirmed the vertically layered reservoir and the need for horizontal as well as vertical and highly deviated wells. The presence of faults that potentially may ompartmentalize the reservoir has resulted in a development plan where the early wells are laid out as producer - injector pairs within individual fault blocks. Each fault block has been designated for either gas injection or water flooding. However, as new information about the reservoir, its geology and degree of compartmentalization becomes available through the drilling of the development wells and early production experience, the location and type of later wells will ensure that the all parts of the field are being produced in an optimized way. Introduction The Terra Nova Oilfield is situated offshore on the Grand Banks, 350 km east-southeast of St. John's, Newfoundland, Eastern Canada (Fig. 1). Water depth in the area is about 95 m. The field is estimated to contain over 150 million cubic meters (one billion barrels) of oil in place, of which around 58 million cubic meters (370 million barrels) are expected to be recovered. Based on a daily production rate of up to 23,850 cubic meters (150,000 barrels) per day, the field would produce for about 12 to 15 years, beginning in mid 2001. Terra Nova was discovered in 1984 with the drilling of the K-08 discovery well. A total of nine wells were drilled in and around the field between 1984 and 1988. Terra Nova is the second major oil field discovered on the Grand Banks, the first field being Hibernia which was put on production in 1997. In August 1996 a Development Application for Terra Nova was submitted to the Canadian-Newfoundland Offshore Petroleum Board (C-NOPB). The application outlined a subsea development with up to six "drill" centres and a Floating Production Storage and Offloading (FPSO) vessel. A total of 32 development wells was included for the delineated area of the field, covering both producer and injector wells. It was anticipated that 10 wells would be drilled and completed before production of First Oil. The selected facility had flexibility to develop additional upside potential in the field provided by non-delineated areas, and another 12 wells were foreseen for these areas.