Swellable Granular Subsurface Seal
Resolute Energy Solutions was formed in 2016 to develop new technologies for oil and gas, with a focus on well plugging & abandonment (P&A) and well integrity.
One of the first areas of interest for Resolute was to find better ways to fill unwanted gaps in well equipment and formations. P&A planning by both the industry and relevant authorities has highlighted an appetite for solutions that allow tubing and casing to be left in place safely when wells are abandoned. This could reduce both the time and costs of P&A.
Resolute’s idea was to deploy a swellable sealing material to seal cavities and fractures, or to isolate specific porous sections of a well. The material would be pumped or ‘spotted’ into the wellbore in a carrier fluid at the location where the seal was required. When the material expanded, it would create a plug. This could potentially be used in drilling and production stages, as well as in well integrity and abandonment.
One important application Resolute envisaged for its swellable seal was for sealing around control lines – present in around 90% of modern wells. Cement is not considered a suitable barrier for sealing around control lines because it can contract when setting, leaving potential leak paths between control lines and tubing. Resolute’s proposed swellable sealing materials are designed to work with cement and would allow sections of tubing and casing to be left in place even in permanent abandonment.
So, Resolute developed a concept for a seal, its technical operation and applications, and made a patent application covering a number of inventions, solutions and applications. It approached OGIC for support to develop the technology further and bring it closer to market.
OGIC agreed to co-fund and support the project, and Resolute selected Robert Gordon University (RGU) as its academic partner for the project – specifically, the Petroleum Engineering Research Group and the Centre for Advanced Engineering Materials in the School of Engineering.
The academic research required by Resolute was to get a deeper understanding of the physical and chemical properties of different materials. This would enable it to develop the most appropriate swellable materials for downhole applications to meet specific functional applications and industry standards.
The RGU team developed and conducted tests on different materials. They outlined the properties of different materials, and tested them under various conditions; and gathered pressure data from squeeze testing.
This enabled them to provide Resolute with important information on the suitability of different materials in varying temperature, salinity and pH conditions. It has also enabled Resolute to address key questions such as the size distribution and concentration of the sealant for different applications.
Using the academic input from RGU and the funding and support from OGIC, Resolute has made big strides forward in developing its solutions. In turn, this has opened the way for other milestone achievements. In 2019, Resolute was selected as one of just ten businesses in the OGTC’s second cohort of TechX pioneers, an accelerator programme that provides support and funding for young companies with new technology ideas.
“The potential benefits to industry of pump-down swellable seals could be significant: well integrity can be reinstated, overall field financial lifetimes can be extended, and when decommissioning comes, well abandonment can be made more cost effective, with improved environmental protection.”
Iain Lees, General Manager, Resolute Energy Solutions