Restrictions on commingled production hampered productivity
Ecuador has several mature oil fields classified as brownfields, and the
country is aggressively seeking to increase oil production. Discovered in 1969,
the Shushufindi-Aguarico oil field uses artificial lift to produce from two
main stacked reservoirs, which have different pressure regimes. Commingled
production had not been an option in the past because the lack of independent
measurement and flow control of each producing layer impeded reservoir
management and petroleum accounting.
Dual concentric completions were historically used to produce both sands
simultaneously, providing little flexibility and necessitating a separate ESP
for each layer. This architecture increased the complexity, risks, and costs
(including deferred production) of completion installation and interventions,
including the scale removal and acid treatments typically needed in
brownfields. ESP maintenance, repair, and replacement required pulling out the
entire completion and exposed the formation to damaging well control fluids.
Consequently, remedial measures were often postponed as long as one pump was
operational, reducing productivity. In 2014, only 66 of 215 dual completions
were active, representing 31% efficiency.
A solution was required that would
- manage simultaneous production from two or more sands
- provide zonal flow control and downhole monitoring of pressure and temperature in real time
- enable back allocation of commingled production
- accommodate artificial lift mechanisms such as ESPs
- enable production testing without intervention
- allow stimulation operations or chemical injection, as needed
- expedite interventions, including ESP replacement
- minimize formation damage during workovers
- transmit data in real time from the field to the office
