ConocoPhillips has been on a quest to find a high volume artificial lift system that will operate reliably in a 250°C (482oF) downhole environment, which exists in certain SAGD applications. This presented two problems:
there were no commercially available technologies for such a high temperature; and
there were no facilities capable of testing these systems.
This paper describes the complexity of building and operating a high temperature flow loop rated for 250°C, and the lessons learned while upgrading an existing flow loop, from the initial design through the final commissioning phases. The paper also describes the issues encountered with the first artificial lift system tested at 250°C, which was a metallic stator progressing cavity pump system, rated for 1100 m3/d (6919 bpd) at 500 rpm.
In the end, the test program not only served to validate and define the pump's performance, but also provided valuable lessons on the completion configuration and operational procedures.
The ConocoPhillips technology group was tasked to find, select, and further develop artificial lift technology with the capability of handling fluid rates up to 1000 m3/d at 250°C (6290 bpd at 482oF) downhole conditions. The goal was not to just find and validate a single system, but to qualify several lift systems, in order to provide the production engineers with a "toolbox" of solutions.
This challenge was divided and approached as two different projects:
find, select and further develop potential lift systems with the needed volumetric capability; and
validate these systems through high temperature testing.
The latter was considered to be the bigger challenge of the two. ConocoPhillips did not operate any fields with downhole temperatures close to 250°C, so validation via field trial was not possible. A more controlled test facility (whether a well or flow loop) was also preferred, so that a comprehensive suite of performance curves could be collected to define the full operating envelope for each lift candidate. A test facility which was not associated with a specific pump vendor was also preferred, to avoid the legal and confidentiality issues with testing third party equipment.
ConocoPhillips decided that an existing high temperature flow loop located at C-FER Technologies Ltd, in Edmonton, Alberta, Canada was the best option for the artificial lift validation testing. The loop had been built as part of a Joint Industry Project (JIP)1 in 2004, but needed to be upgraded to allow for testing at 250°C. This was a costly endeavor, and ConocoPhillips and C-FER contacted other Canadian SAGD operators to see if the upgrade could be completed as a JIP, thus sharing the capital cost among several interested parties. However, no other operators were interested in upgrading the loop at the time, so ConocoPhillips proceeded to fund the project entirely.