Qualification test proves superior ESPCP stator performance for light oil | SLB
Tech Report

Qualification test proves superior ESPCP stator performance for light oil

Published: 05/20/2024

image of the PowerEdge tool

To enable rodless lifting of any API gravity oil and high gas and solids content, SLB innovatively reengineered the pump components in developing the new Reda™ PowerEdge™ energy-efficient wide-range ESPCP system.

  • The composite stator of the new ESPCP system features a thin, uniform elastomer wall supported by a rigid composite structure with high heat dissipation for running hotter and faster without generating the internal frictional heat that causes failures in conventional PCPs.
  • Unlike traditional PCP stators, which have elastomers that swell and cause interference with the fit of the rotor and early failures when exposed to light oil, the composite stator design and its thin, uniform elastomer minimize swelling, enabling smooth and continuous operation in light oil environments.
  • The PowerEdge ESPCP system also eliminates the use of traditional adhesives for robust higher-temperature operation. Running a conventional PCP in temperatures above 185 degF [85 degC] causes adhesion issues between the elastomer and metal housing that result in debonding of the rubber from the housing.

To qualify PowerEdge ESPCP system's performance and stability in lifting oil from mature wells with low production rates, both performance and endurance tests were conducted on the composite stator at C-FER Technologies in Edmonton, Alberta, Canada. The tests used a fluid formulated to simulate light oil (14% aromatics) at temperatures up to 248 degF [120 degC]. The five weeks of tests were primarily at 350 rpm and increased to 450 rpm in the final week—speeds higher than those typically used for conventional PCPs. The elastomer’s volumetric swelling stabilized just nine days into the testing.

As shown in the cross-sectional photograph taken halfway through endurance testing, the following superlative results were documented by endurance testing of the PowerEdge ESPCP system.

  • The pump had no visible oil precipitation, elastomer deformation of the stator cavity profile, or elastomer material degradation after testing, as evidenced by the stable low swell.
  • No debonding between the composite and elastomer was observed, and no elastomer debris was found in the flow loop.
Location
Canada, North America
Background

Traditional progressing cavity pump (PCP) stators cannot be used for light oil because they cause elastomer swelling that interferes with the rotor, leading to premature failure. Additionally, higher temperatures (>185 degF [>85 degC]) degrade elastomer adhesion, debonding it from the metal housing. These limitations mean operators must produce low flow rates in wells with light oil or higher temperatures by using rod lift systems. Rod lift introduces other constraints, including poor handling of gas and solids content, installation restrictions in deviated wells, and a high likelihood of failure due to rods parting or puncturing tubing, in turn requiring a workover.

Products Used
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