Unity delivers 60%+ cost and efficiency gains using unique intervention technology in North Sea decommissioning programme

Source: press release, 15 March 2022

Unity’s Surface Intervention System, part of the company’s compact technology range, is delivering efficiency savings of between 50-75%
Unity’s Surface Intervention System, part of the company’s compact technology range, is delivering efficiency savings of between 50-75% (photo: Unity)

Unity, Europe’s largest provider of well integrity solutions, is supporting a North Sea well decommissioning programme for a major international operator using its uniquely compact and multifunctional Surface Intervention System (SIS). Unity’s work on this multi-well campaign is worth an estimated six-figure sum.

The SIS has already completed intervention work on the first well, where it was deployed offline to set a shallow bridge plug in preparation for the removal of wellhead equipment. Unity’s stand-alone technology replaced the need for traditional intervention equipment and delivered significant savings to the operator in cost, time and efficiency, by working below deck while P&A drilling operations were ongoing. Compared to traditional methods, the intervention was performed around 60% faster and delivered a cost and personnel package saving of 66%.

During the project, deck space and bed space were restricted due to the drilling operations, but Unity’s compact SIS technology, which requires just two technicians to operate, provided the ideal shallow intervention solution. With a small footprint the SIS was easy to accommodate on the platform below the drilling rig in a restricted well bay. The SIS and pressure control package were rigged-up below deck using a small A-frame crane provided by Unity. The plug was set first time and the equipment was rigged down all within 24 hours.

Gary Smart, CEO at Unity says, “The SIS has great utility and has been used by several operators for milling, inspection, fracturing and P&A operations, generating material savings against traditional shallow well intervention techniques. This technology is soon to be complemented by our newly announced Compact Shear Seal Valve technology, reducing the footprint and weight of the overall system even further.”

The SIS is the first multifunctional shallow well intervention system on the market and combines heavyweight capability within a compact and mobile package. It is simple to operate, fast to deploy and ideal to assist in the end phase of well P&A activity through plug setting and the removal of Xmas tree and wellhead equipment. In addition, it can be used to carry out inspection and remedial work of the internals of the surface equipment and tubulars prior to removal. The SIS has a powerful hydraulic motor, driving a push, pull and rotate function which can rival wireline or coiled tubing capability.

Unity has established an impressive well decommissioning project track record which currently extends to over 150 wells with another 230 in the pipeline over the next 3 years. Work has included plug setting, isolation verification, removal of Xmas trees and surface wellhead equipment, installation of suspension flanges and manufacture of wellhead removal tools. The company is experienced in working with all makes and types of surface wellhead equipment.