DHSV Line Block UK Subsea Wellhead 

Product: Mac-Seal 02 Control Line Block  

 The client   

 A major oil and gas operator in the UK approached us for assistance in creating a control line block by deploying our chemically engineered specialist sealant product, Mac-Seal 02, into the control line. 

The results   

The testing involved pressure testing the isolation in the direction of the flow by raising the wellbore pressure, which was linked to the DHSV Control Line at the sea bed. This resulted in a positive pressure test of 2100 psi on the isolated DHSV line. Subsequently, a second pressure test conducted 24 hours later also yielded positive results. Overall, we achieved our objective by providing our customer with a safe, effective, and efficient isolation solution. They were delighted with the outcome.  

The challenge   

Hydrocarbon fluids leaked into the sea due to a loose hose connection on the subsea tree's DHSV. The leakage originated from the DHSV feed line, which had a hydraulic coupling problem at the tree, resulting in fluid discharge. With the WRDHSV recovered, the DHSV control line system remained open to the tubing bore, which created the issue. 

KCI was commissioned to create isolation at the loose connection to allow the planned well abandonment operation to be carried out safely and with no further environmental hydrocarbon discharges. 

The solution 

To facilitate the planned well abandonment operation and to prevent further environmental damage from hydrocarbon discharge, KCI was tasked with creating an isolation at the loose connection. Leveraging our bespoke engineered product, Mac-Seal, our technical service specialists deployed Mac-Seal into the control line hot stab via ROV. This effectively blocked the hydraulic system leak and created the necessary isolation. The Mac Seal material is fully cured within 8 hours.