D3 Case StudyClient: A North Sea Oil & Gas OperatorService: Waste & Materials Inventory and Waste Assurance

The ProjectFor the decommissioning of a North Sea gas platform, the Operator required a detailed Waste & Materials Inventory as part of their Decommissioning Programme. The platform comprised topside with steel jacket, tied into four separate gas fields. The scope included all subsea installations and pipelines as well as the jacket and topside.

In addition to the Waste & Materials Inventory, the Operator was also looking for support on the development of the Waste Management Plan for the decommissioning works.

The ChallengeWe faced several challenges throughout this project, including the complexity of field ownership which involved four subsea fields, each with different ownership and jurisdictions throughout the UK and Norway. As part of the project, D3 had to consider waste characterisation in both UK (EWC) and Norwegian waste coding.Furthermore, for the subsea assets and pipelines, there were intricacies in which pipelines and assets were scheduled to remain , versus those for removal. With D3’s DAWN* being able to record asset data individually, as well as split a pipeline into sections for remain and remove, we were able to develop the materials inventories according to the scope of subsea works.

* DAWN: Decommissioning Assurance through Waste kNowledge is D3’s information management system for preparing materials inventories and managing waste through the decommissioning process

Pipelines

Total inventory line entries

Total tonnage

51 km

3,271

44,974Te

Sub-Sea

1 3

Platforms

1

D3 Case StudyClient: A North Sea Oil & Gas OperatorService: Waste & Materials Inventory and Waste Assurance

The SolutionD3’s team of engineers and waste management experts tackled the project with the same proven and consistent approach as for all the past offshore decommissioning inventories, working as a team to meet the 3 month timeframe.

Since the platform had a R2S 360o walk around photo-graphic record, we did not have to perform any offshore verification visits, cutting costs and time!

The resulting waste and materials inventory included 3,271 entries for individual items and structural elements, totalling more than 44,974t. Within the final decommissioning scope, the largest waste and materials fractions are steelwork and concrete (approximately 20,425t combined) with the other waste streams including nearly 500t of potentially hazardous wastes and NORM.

Value AddingAll waste and materials data/information held on DAWN for subsequent use as decommissioning develops with online supply chain access as required;

The waste and materials inventory data being digitised meaning that any changes on decommissioning scope are readily replicated in the inventory and subsequent waste management; and,

Each waste and material being linked in DAWN to a Waste Management Protocol allowing the Operator to utilise these protocols for the development of its Decommissioning Waste Management Plan and include the protocols in contracts throughout the supply chain.

Next StepsOn completion of the Waste and Materials Inventory, D3 have been retained by the Operator to provide ongoing waste assurance services through the subsequent decommissioning cycles. This includes keeping the waste management protocols updated for each type of waste and material present on the platform to be decommissioned, where these protocols specify the regulatory compliant handling and treatment activities for these wastes and materials.

This provides the operator with assurance that the supply chain for the decommissioning works, through adherence to the protocols, will be regulatory compliant and reduce risks of breach...one less risk for the Operator to manage!

Martin Bjerregaard 07969 725 418 martin@d3-consulting.com d3-consulting.com