Sand Management Practices for Extended ESP Run Life, a Study Case from a Mature Field in Ecuador

Abstract

Abstract To analyze some factors that affect electrical submersible pump (ESP) performance and its reliability, focused on sand control practices (downhole devices as well as chemical sand consolidation), fluid characterization, and bending stress effects. To describe some study cases where these practices were applied over the last ten years leading to an increase in ESP reliability. To show ESP performance for 74 installations executed during the latest development stage in the Tarapoa block. ESP performance in Tarapoa is affected by downhole devices sand production efficiency such as screens, automatic solids fallback preventer valves, and chemical sand consolidation treatments, the study starts with a summary of these experiences and related issues. Viscosity influence on ESP performance is studied since design stage sensitivity to water cut, emulsion, API gravity, and sand content is included. During the production stage, the need for single, double, or multiport capillary systems is described as well as the chemicals used. The finite element method is used to evaluate the stress effect during ESP installation and optimal setting depth for different well trajectories. The best method for sand control in directional wells is chemical sand consolidation, this technique does not require additional downhole equipment and the effect on the productivity index is negligible. Standalone screens are recommended for horizontal wells but their effectiveness in sand production is limited. Automatic solids fallback valve provides some protection to ESP by preventing sand deposition when well is shut-in, up to 2,320 days running with this equipment. The production status of ESP under different viscosity conditions is simulated improving ESP run life. In addition, chemical injection effectively improves the physical properties of the fluid, which makes ESP relatively stable. Through the application of finite element software, a reliable stress distribution through the equipment was obtained. This analysis is used during installation operation and to define recommended setting depth. Average ESP run life extended over 1,900 days with a Mean Time Between Failure (MTBF) over 4,000 days. This study summarizes the practices used to improve ESP performance over the last 10 years. ESP performance is affected by various factors that are described in this study from downhole sand control devices, chemical treatments, accessories installed along with ESP, and chemicals used during the production stage.