Unity has developed a new technology to pressure test suspended mudline wells from a vessel before plugging and abandoning (P&A) activity for improved safety and cost savings.
Initially, the Temporary Abandonment Cap Test Tool (TACTT) was deployed to support Spirit Energy’s end of life project located in the Southern North Sea.
Unity said that TACTT is the first technology of its kind that can seal on to any type and size of temporary abandonment (TA) cap. It can pressure test the seal to ensure well containment and later on test and vent pressure from below the cap and leaves a secondary seal in place. Instead of using a rig, the tool can be cable deployed from a vessel through open water.
Designed according to Spirit Energy’s specifications and deployed from a rig in the North Sea in 2014, the TACTT technology allows for vessel deployment and opens up further opportunities. Using the technology, the operator will be able to get knowledge with regard to the amount of pressure accumulation below the TA cap. This can be accommodated in the operator’s plans for decommissioning.
Unity CEO Gary Smart said: “Decommissioning is the inevitable end-stage of any well, and although the industry is developing many solutions to extend producing life, we must also look to innovate further new technology to support operators’ P&A obligations.
“We developed the TACTT in response to operator demand, as there was no specific solution available on the market to pressure test suspended mudline wells behind their TA caps prior to removal.”
Spirit Energy drilling and wells director Olav Log said: “Unity’s TACTT allowed Spirit Energy to successfully abandon two North Sea wells in line with UK Government regulations. The tool removed all risk associated with re-entering a suspended well and the ability to deploy by vessel provided significant project savings.”