Increased energy demands for oil and gas have triggered the need to exploit high-pressure/high-temperature (HP/HT) fields, including extreme HP/HT and ultra HP/HT fields. However, well completion of ultra HP/HT fields is posing great technological challenges to operator and service companies. Existing completions technology seems to be reaching its design limits at around the 15,000 psi and 450°F territory.
As operators continue to drill into deeper and more extreme formations, the demand for technologies to suit these environments will steadily increase. Great efforts have been made to overcome the hurdles to develop safe and reliable completion tools qualified for conditions in excess of the 15,000 psi and 450°F territory across the industry over the years. A technological milestone was recently set in packer seal system development—the first 25,000-psi 500°F packer seal system.
Qualification testing was conducted with nitrogen to all the rating envelope points at 500°F with a cool down to 250°F.
The packer seal system passed all tests with no visible seal element extrusion, and no leaks were detected at any of the load points during testing.
This paper presents how this innovative seal system design evolved from several field-proven HP/HT seal systems, and how technological challenges are addressed by adopting state-of-the-art materials and design processes. The paper includes information about conceptual design, design optimization using finite element analysis (FEA), material characterization for both metallurgical and seal material, and seal assembly manufacturing. The qualification testing processes for this 25,000-psi 500°F packer seal system are also described, along with the market potential for these ultra-HP/HT wells.