Challenge:
Cliff Head oilfield, located offshore Western Australia, utilizes a Coiled Tubing deployed Electrical Submersible Pump (CT-ESP) system for its complex horizontal oil wells. The field faced a significant challenge: declining production rates due to solids build-up within the ESPs, which impaired pump performance. Furthermore, the offshore platform was ‘not normally manned’ (NNM), adding additional complexity to diagnosing and resolving these well performance issues in a cost-effective manner without invasive techniques.
Solution:
A comprehensive analysis combining real-time ESP and well data with well performance modeling software was conducted. Individual well models were developed to identify the root cause of declining performance, revealing a “performance limiting factor” (PLF) caused by solids accumulation in the ESPs.
In response, targeted chemical soak treatments were applied to two production wells, removing flow restrictions and restoring efficiency. Production trends were closely monitored to assess performance before and after the treatments. Additionally, reservoir simulation and ESP performance analyses were carried out, which identified the potential for further optimization by upsizing ESPs.
Value Added:
The targeted chemical soaks resulted in significant production increases of 17% and 48% in the treated wells. Based on the reservoir simulation results, field-wide production improvements of up to 50% were identified by upgrading to larger ESPs. This integrated approach of data-driven well diagnostics and proactive treatments delivered material production enhancements, minimized downtime, and improved the long-term efficiency of the Cliff Head oilfield.
