Summary of Lessons Learned: In advance of the removal of the Brent Delta topside by SLV, the owners prepared the installation for CoP, completed a programme to plug and make safe the wells, rendered the topside hydrocarbons-free, and prepared the topside for removal.
The Lessons Learned from this multi-faceted programme of work over approximately 10 years are summarised below.
Project-wide Planning: • Decommissioning needs to be considered early in the EOFL phase, i.e. before CoP • Lack of planning is likely to erode overall Asset value; early planning is likely to enhance Asset value • A focus on Abex may highlight the need for early Asset investment • Transition into the Decommissioning phase is likely to be just as challenging (if not more so) than production • Start early – CoP is often triggered by an unplanned event – Be Ready! – Reduces some risk and ~20% maintenance hours but utility reliability is crucial; e.g. of cranes, power, safety systems – Prioritise decommissioning work appropriately pre-CoP: it’s a major opportunity to get into a project mindset • Early strategic decisions will have a major impact to overall decommissioning costs • Hydrocarbon-free is a more significant milestone than CoP; achieving this milestone can lead to a reduction in maintenance costs of up to 50%. • A new risk profile means different ways of working • Engage the market in decommissioning solutions: Continually monitor market conditions to optimise: early input from supply chain • Organisation Design / People / Skills Planning: improve collaboration between Project / Operations / Wells • Focus on down-manning, a milestone that has a significant effect on cost and offshore exposure.
Cost-savings: • Typically, over 40% of the decommissioning costs on manned installations are associated with the P&A of platform wells. • Recognise the hierarchy of value drivers – least to most valuable – Wireline P&L before P&A – Wireline P&L concurrent with P&A – Commence P&A before CoP • New ways of working are driving down costs (Well P&A) and duration (post-CoP Opex) – Individual wells – appropriate P&A barrier philosophy – Suitable platform focus
– POB – Integrated rig and asset crew – Application of new technology/techniques – Conductor recovery using the platform crane proved to be much cheaper than using the rig.
Work-scopes: • Freeze engineering solution at the right time; a mindset of continuous improvement preserves value • Flexible execution: – Project led, but construction driven – Multiple work fronts available for fall back work – Flexibility as demand changes, capability to manage/adapt – Offshore integration – Platform Services under Project – Reduced & simplified interfaces: rapid decision making