Abstract:

All of Valeura Energy’s operating fields in Gulf of Thailand use Electrical Submersible Pumps (ESPs) as a main artificial lift to produce crude oil. The continuity of production depends on the run-life of the equipment. In other words, the longer the ESPs’ run-life, the lower the Operating Expense (OPEX). However, millions of dollars have been spent on unnecessary workovers to replace ESPs that failed before delivering their expected service life. To reduce workover costs, many components need to be considered. A holistic review process was set up to improve the run-life, considering multiple aspects such as contracting strategies, repetitive failure analysis, equipment design, operation, monitoring, and maintenance.

Typically, an ESPs full life-cycle was use as the basis to assess / improve run-life, starting from design, manufacturing, installation, start-up, operating, through the ultimate pulling, tear down and analysis of the pulled ESP unit. In reality, there are other aspects to be considered as part of the processes to improve run-life.

Contracting is the first point to tackle to ensure that contractors will deliver best equipment and services. The run-life target was included in the scope of work and was tied in with the payment scheme. The second point is to identify the recurring failure modes, considering the possible root causes to improve sizing, material, and metallurgy selections. 

Moreover, the full breadth of available technologies in the market were also considered and selected as part of the design recommendation for both downhole and surface components. The QA/QC processes, installation procedures as well as the harmonic measurement and power supply quality from the surface facility were integrated into this improvement plan as well. In house Artificial Intelligence also played an important role for ESP performance and surveillance. The last piece of this jigsaw was to embed the ESPs’ run-life as part of corporate KPIs and to conduct quarterly reviews with contractor to identify the gaps and craft improvement plans.

At the early stage of implementation, there is no early life failure within 90 days after the installation. The production team had an operating awareness of ESPs. The surveillance system is also integrated and plays an important role in maintaining uptime.   It took approximately two years to lift the run-life up from 820 days to be above the target at 1095 days, and the current average run-life has further increased to approximately 1900 days. The lessons learned from this improvement have been implemented as a master plan for new field developments. Millions of dollars in unnecessary operating costs related to the ESPs’ run-life, such as workovers and deferred production, were saved over the last ten years.

Bio:

Thanudcha Khunmek is a Senior Completion and Well Services Engineer at Valeura Energy in Thailand with more than 19 years of experience in artificial lift and well completion design and operations. In his current role, he oversees all aspects of completion design, from the wellhead to completion equipment, including Electrical Submersible Pumps (ESPs). He began his professional career in 2005, focusing on artificial lift and completion techniques. Before joining Mubadala Petroleum in 2014, Thanudcha worked as an Artificial Lift Product Line Manager at Baker Hughes.