Triton Energy Ltd. (Triton) (acquired by Amerada Hess Corporation in August 2001) and Energy Africa (15% WI), set a benchmark for the oil industry by discovering and developing a deepwater Equatorial Guinea, West Africa field and establishing production to a FPSO in less than 14 months. The fast-track development project operated by Triton commenced in October 1999 following the Ceiba-2 confirmation well. The completion strategy and its success played a major role in realizing this world record achievement and continually improving well performance in the Ceiba field.1
As with any new field, development of the optimum completion strategy evolved based on lessons learned. Eight (8) producers, one (1) sidetrack and three (3) water injection wells have been completed to-date. The initial five (5) production wells (Phase I), utilized cased-hole completions. Four of these five wells employed single-trip perforating and gravel pack (STPGP) completion techniques. These completions produced upwards of 18,000 bopd with moderate skins. The fifth cased hole production well was completed using a single-trip perforating, gravel pack technique in conjunction with a hydraulic fracture treatment (STPFP). This resulted in an improved skin factor and Productivity Index (PI). The remaining three (3) producers were completed as open hole gravel packs using mineral oil based mud (MOBM) as the reservoir drill-in fluid (RDF). Three seawater injection wells have also been completed to date. Two (2) were performed as STPGP's and one (1) as a STPFP. These recent changes of methodology have proven successful in further enhancing productivity index and reducing skins.
The versatility and flexibility required to successfully incorporate the required strategy changes in such a short time frame, reflects the weighted risk taking approach and aggressive management style of the operating company and a strong commitment of the service sector.
Major Contributors to Project Success: Development of strategies to allow flexibility and overcome supply, logistical and operational constraints associated with remote operations. Optimization of completion techniques and equipment Successful utilization of a single trip perforating/gravel pack system for wells with world class, high permeability intervals Successful utilization of a single-trip perforating and screen running technique in conjunction with a Frac-Pack treatment Development of strategies to address issues, problems and results associated with transitioning from a single trip perforating and gravel pack to open-hole gravel pack completion Development of strategies to address issues, problems and results associated with testing wells at rates in excess of 11,500 BOPD to floaters.
Introduction
Mbini-1 was spudded on August 19, 1999 and reached total depth September 23, 1999. Flow tests of 12,401 bopd of 30° API oil (surface equipment limited) were flared from a 160 feet interval. Shortly after the discovery, the name of the well and field were changed in honor of the largest native tree in Equatorial Guinea, the Ceiba.
Ceiba-2 was drilled at an adequate distance from Ceiba-1 to prove economic viability of the project. Ceiba-2 cut a 300 feet oil column with an oil/water contact similar to that found in Ceiba-1. This provided the confirmation that Triton had discovered an economically viable field and a fast tracking strategy was initiated.
Within three months of the discovery of Ceiba-1, Triton had proposed a development plan and received approval from the government to proceed to exploit the field (Figure 1).
