Case Study 4 header

Case Study 21

Technical Objective
Full workover avoided through innovative use of an LWIV to perform first subsea slickline intervention in Nigeria.

Offshore, Africa.

National Oil Company.

Well Type
Single string oil producer; 5-1/2", 17lb casing.

5-1/2" SIM Retrievable Bridge Plug and Boost Running Tool

The Challenge
A Customer experienced a Tubing Retrievable Surface Controlled Sub-Surface Safety Valve (TRSCSSSV) failure on its subsea well at 951m, with 7000bopd production locked in.

The objective was to offer a cost effective solution which included setting a new type of valve in place of a full workover, in a challenging subsea environment.

The TRSCSSSV is a safety valve system designed to be fail-safe and isolate the wellbore in the event of any system failure. Its malfunction in the ‘closed’ position had clear implications for well activity.

Ensuring well integrity was not compromised during the operation was a priority.

Peak’s Solution
Peak collaborated with their Nigerian partner to support a Light Weight Intervention Vessel (LWIV) operation using slickline. LWIV costs are significantly less than a semi-submersible rig with no requirements for support vessels. 

Peak utilised the unique design of its SIM System to mechanically set (via slickline) a 5-1/2” SIM Retrievable Bridge Plug above the failed valve at 951m using Peak’s Boost Running Tool.

The Boost Running Tool is activated by downward jarring which primes an in-built hydraulic chamber, creating an augmented high force output, to ensure the device is fully set. The tool automatically shears when the required setting force output is achieved, allowing the tool to be released from the device.

A spacer measuring 5.4m, connected below the SIM Plug, acted as the hold open device and an autonomous Safety Valve below the TRSCSSSV, completed the flow control package.

A successful In Flow Test was carried out ensuring well integrity was ascertained and the well was returned to full operation.

Value to Customer
Efficient communication ensured Peak and their Nigerian partner worked competently to provide the client with a prompt and cost effective solution.

The successful replacement of the valve (as an alternative to a full workover) and innovative use of an LWIV in Nigerian waters, to perform subsea slickline intervention, was significant.


Product Code(s): SIM Retrievable Bridge Plug - 351; Boost Running Tool - 364