The Oooguruk project is located in the Alaskan Beaufort Sea and consists of a 6 acre gravel drill site approximately 5 miles offshore in 4.5 feet of water. The drill site is connected to an onshore facility by a complex flowline system consisting of a 5.7 mile subsea buried flowline bundle which transitions onshore to a 2.3 mile traditional North Slope above ground flowline support system. Approximately 38 horizontal extended reach wells will be drilled into two horizons to develop the field. Drilling commenced in December 2007 and the field is scheduled to come online in 2008.
This paper generally describes the Oooguruk field development concept, project execution strategy and the challenges faced during planning and construction. Details regarding island design, environmental design criteria, pipeline design and construction, and drilling rig capabilities are included in other technical papers.
In the winter of 2003 (January - April), Pioneer Natural Resources (as operator) and Armstrong Oil & Gas drilled three wells (Ivik No. 1, Oooguruk No. 1, Natchiq No. 1) in Harrison Bay, northwest of the Kuparuk River Unit Field. Pioneer determined that the resource was economic to develop after analyzing the results from these wells and subsequently acquiring well and geological data over the area. Pioneer would develop two separate reservoirs called Kuparuk C and Nuiqsut from a single drilling center.
The development plan consisted of three major components: an offshore drill site (ODS); an onshore interconnect and production support facility (OTP); and a system of flowlines, power cables and communications cables connecting the onshore and offshore facilities. Three phase production would be delivered through an interconnect to existing infrastructure at the Kuparuk River Unit (KRU) drill site DS-3H operated by ConocoPhillips. The location of these facilities is illustrated in Figure 1.
Five wells, three producers and two injectors, would be needed to recover the Kuparuk reserves in the original plan. A total of 33 wells, 18 producers and 15 injectors, would be drilled to recover the Nuiqsut reserves. The estimated recoverable reserves for the project were between 50 and 90 MMBOE. The depletion plan for both reservoirs would require long horizontal wells. Recovery would be enhanced by incorporating water-alternating-gas (WAG) injection capability and by installing electric submersible pumps (ESPs) in each of the production wells. Since the drill site would need to be self sufficient due to isolation during certain times of the year, a Class 1/Class 2 disposal well would also be drilled.
