Innovative conductor deflection tool enables reuse of platform well slots

PROJECT OVERVIEW

An offshore Middle East operator approached Claxton, a Cutting and Decommissioning brand in Acteon’s Energy Services division, to design, manufacture and install an innovative solution to enable the replacement of corroded conductors and non-profitable wells within a platform with a new well.

THE CHALLENGE

Due to the age of the well conductors and offshore platforms that sit within a corrosive environment, an engineered solution was required which would allow the customer to drill new wells reusing the existing platform slots. The life of the field needed to be extended using a cost-efficient approach whilst minimising the number of operations and associated risks on the project.

CUSTOMER GOAL

The customer required a solution to extend the life of their offshore assets to continue production from a field that had many years remaining but was no longer feasible with the existing well infrastructure.

OUR SOLUTION AND ITS COMMERCIAL BENEFITS TO THE PROJECT

We develop market-leading services and integrated solutions

Claxton engaged with the key stakeholders to fully understand the structural and design criteria requirements of the new well and its interface with the platform and other wells, and the methodologies of installation available to the operator commonly used in the region.
Common methodologies for asset life extension, such as the use of an above mudline whipstock, were considered and discussed but there were concerns about the platform not being able to withstand the installation loads of the new well, so an alternative approach was required with the development of the conductor deflection tool (CDT).
Claxton developed the CDT, enabling the customer to deviate a new well using the platform guide slots, whilst preventing the transfer of the installation loads to the platform; instead, the load transferred to the stump of the older well.
The design of the CDT features a larger conductor pipe in which a long vertical window is cut. Low friction pads are fitted at the top and bottom of the window to provide the new conductor a 2° deviation and reduce vertical running loads.
The CDT has robust, high-strength threaded connections to aid rig handling; eccentric centralizers to ensure the new conductor is vertical; a cement basket to protect the new conductor from corrosion and avoid future integrity issues.
Centralising fingers and hardened blades were used to ensure secure alignment to the existing stub/stump and stable centralization to ensure verticality.
The CDT provided a secure alignment to the existing stub/stump and stable centralization to ensure verticality within the required limits at the upper end of the well. The design also incorporated a threaded connection to aid rig handling and reduce vertical running loads through the introduction of glide pads.
The CDT design was unique to the project and with each iteration/new order, the product is being refined further to accommodate new challenges.

We work at scale with a proven track record for delivery

Claxton applied experience knowledge and track record of providing bespoke equipment to guide discussions with the customer structural team and make sure all key requirements were catered for including risk mitigation.

We optimise the project to increase commercial value

The CDT design will withstand the impacts of the harsh subsea environment and well loading throughout its design life.
CDT enables slot recovery wells to be drilled through existing platform guides and next to existing wells then deflect the drill string and conductor.
Extended the life of the field in the most cost-efficient way possible whilst minimising risks during operation and throughout the design life of the CDT.