Single-Trip Perforate and Frac-Pack Completion With High-Efficiency Frac Gel in Bonga Phase II

摘要

The Bonga field is located offshore deepwater Nigeria. Part of the second phase of the development comprised five frac-pack treatments executed in a multi-darcy environment. With permeability variations from 1 to 7 Darcies, the salt-tolerant fracture fluid that was used for the frac treatments had efficiencies in the order of 40%, compared to 10 to 15% most commonly achieved in such treatments (Witteveld, 2004; Cipolla, 2005). Use of such a high-efficiency fluid resulted in substantial reduction in pump rates and horsepower requirements. All five treatments were performed from a stimulation vessel, three of the treatments with the conventional two-trip technique and two using the single trip perforating and frac-packing technique. The single trip system allowed the completion time to be reduced by 1 to 2 days as compared with conventional system. This paper discusses Bonga Phase 2 frac-pack treatments, with a comparison of the two techniques (single trip versus conventional) from a cost savings as well as well performance standpoints based on field applications. Design, execution and evaluation of the treatments are detailed, along with a discussion of the fluid system, and the lessons learned during the completions campaign.