Slot-Jet-Isolate: A Next-Generation Explosives-Free Remedial Technology

Abstract

Abstract The Slot-Jet-Isolate (SJI) system is a newly developed, explosives-free and low-footprint remedial technology designed for full flexibility in the remediation and testing of challenging annuli for a variety of applications. An extensive full-scale testing programme was executed with the support of industry sponsors to demonstrate the effectiveness of the Slot, Jet, Isolate (SJI) concept. Testing was performed on fully-cemented casings to confirm the ability of the slotting system to develop a hydraulic connection with the annulus for even the most challenging annuli not previously within the envelope of traditional systems. The learnings have been applied to further enhance the power of the slotting blades and robustness of the tool, and determine operational limits prior to initial field deployment. Following the success of the first phase of testing, the tool was deployed for an operator in the UKCS to successfully slot casing and displace oil-based mud from the annuli of four subsea wells prior to the setting of environmental plugs, removing the need for explosives and successfully conducting operations more efficiently than the established approach. Since this first application, the tool has subsequently also been run offshore Netherlands to slot casing to facilitate washing and removal of annular solids prior to pulling casings during P&A operations. The potential of the technology for future fully-rigless deployment via the use of Coiled Tubing was also confirmed. This paper will report on how the SJI system was developed with the help of effective collaboration between industry partners to accelerate its maturation from concept to successful field deployment in only 18 months, and will further demonstrate how this flexible technology may also be configured for applied casing recovery applications, in addition to its future intended application to annular cement remediation for well plug and abandonment (P&A).