Innovative Technology for Gas Handling and Solids Control to Extend ESP Run Life: A Villano Field Case Study
Flow instability caused by free gas interference and solids production is one of the primary threats to ESP reliability and run life in mature, depleted reservoirs. In the T Sandstone reservoir of Villano Field, Ecuador, the combination of high gas-liquid ratio, low bottomhole pressure, and active sand production creates operating conditions that conventional ESP configurations have proven unable to sustain reliably. Historical data from this reservoir with low productivity index in a highly depleted zone indicates an average ESP run life of approximately 285 days, with 84% of failures attributable directly to gas interference or solids ingestion. This paper presents the engineering basis and field validation of an integrated downhole completion system that simultaneously addresses both failure mechanisms through three interdependent innovations: a pre-charge pump (gas booster) installed upstream of a tandem gas separator with a blocked-intake design that compresses the multiphase mixture before separation, improving gas segregation efficiency from approximately 45% to greater than 90%; a lower hydrocyclone desander providing continuous centrifugal removal of sand particles smaller than approximately 35 micrometers in diameter through centrifugal separation, before they reach the rotating assembly; and an upper gravitational desander above the main pump discharge that captures settleable solids during shutdown events, preventing backflow particle accumulation during restart. Field results from Well A demonstrate a 31% reduction in mean intake pressure, transition from highly unstable intake pressure fluctuations between 400 and 700 psi to a stabilized level around 380 psi, a 77% decrease in motor current fluctuation amplitude, and 100% operational continuity in the post-installation monitoring window. Weibull reliability modeling projects an 81% improvement in mean time to failure from 283 to 514 days. A set of practical recommendations for gas management and solids control in similar wells is derived from the operational experience documented in this study.