Sand Control Robustness in a Deepwater Development: Case Histories From Girassol Field (Angola)

摘要

Wells in the Girassol field, offshore Angola, are situated in very deep water and have being completed in unconsolidated sandy turbiditic reservoirs. Today in Girassol which includes also Jasmin reservoir, 29 wells have been completed and connected to production facilities and pressure maintenance is coming from 13 water injectors and 2 gas injectors. The completion strategies employed have included mainly stand alone screens in open hole and cased hole frac-packs. A review of the design for both producers and injectors, along with the criteria related to the sand characteristics, and off-shore implementation of the completions will be described. Production strategy recommendations to minimize the sand risk during well start-up and ramp-up and also well steady-state production will be given. This paper will provide an overview of the behavior of both sand control techniques after 5 years of production and injection. An in depth analysis of the different productivity/injectivity characteristics such as drawdown values applied and PLT observations during these 5 years allow us to draw some general recommendations for these types of sand control techniques when used in a similar geological environment. Impact of the measured drawdown values, on the sand control robustness will be described.