Subsea gas-lift design for the Angola Kuito development

Stable production with minimal fluctuation in gas/liqnid ratio (GLR) is critical when designing gas-lift systems for subsea applications. Subsurface gas-lift equipment must last the life of the well, and the unloading and operating procedures minimize erosion of the gas-lift valve and orifice. Dynamic modeling was used to determine the optimum orifice size for long-term operability over a range of injection rates, water cuts, and productivity indices. Also, the model was used to develop startup procedures that minimize erosional effects on the downhole orifice and help answer questions regarding cyclic-production pressures at the subsea wellhead.