When assets, either onshore or offshore, approach the end of their service life, the options for oil and gas asset decommissioning or lifetime extension should be properly and strongly considered. This often involves the performance of a variety of risk, technical hazard, economic and environmental assessments to determine the path that best meets the ultimate goals and objectives of the Operator.
When Cessation of Production (CoP) is reached, there are two major considerations that must be made, which includes:
- Mothballing the plant until decommissioning operations can commence
- Proceed directly to formal decommissioning operations following CoP
Where oil and gas asset decommissioning occurs following a significant period of time in mothballed state, those facilities will be required to be maintained during the period of mothballing so that SCE barriers remain live and the eventual dismantling process can take place safely. The facilities decommissioning process, when and where implemented, should achieve the highest practicable standards of safety, whilst at the same time realising an optimal balance of technical, environmental, societal, and economic standards.
There are a number of detailed assessments that are required as part of this decommissioning process, this should serve to consider the following key priorities:
- To determine if there are any potential further uses for the facilities (i.e. jacket structures, topsides structures, onshore plant structures, offshore and onshore process plant and all associated appurtenances) either at the present location or at other potential locations across the globe
- To examine any and all relevant issues associated with the full removal of the installation(s) and all associated materials to achieve a clear seabed or to return onshore land back to green-field use
- To undertake a specific process of comparative assessment to allow authoritative and comparative evaluation of the complete removal of jacket structure(s) against potential alternative options (such as partial removal, toppling at site etc.); such considerations, however, are unique to jacket structures and will not apply to other elements of the decommissioning scope
- To describe and compare all viable and alternative options for decommissioning and any associated regulatory obligations that are pertaining thereto
- To define and understand certain areas of decommissioning which may be universally acknowledged as challenging (such as from decommissioning studies, lessons learned, guidance and the like)
Oil and Gas Asset Late Life Operations and Decommissioning
AIE proactively supports its clients to navigate the technical and regulatory complexities of late-life operations through to formal decommissioning. We recognise that Operators are faced with the conflicting challenges in present-day uncertain market conditions of maximizing economic hydrocarbon recovery, set against a back drop of high oil price volatility and low oil prices generally, with CoP and asset decommissioning becoming a more realistic prospect within the forthcoming period.
We understand that decommissioning operations, in particular, require significant capital investment with very little or no real return for Operators. We also recognise that there are a number of options available to Operators when faced with decommissioning, as are summarised in the illustration below for offshore plant. However, irrespective of the options that are chosen, there are a number of requirements that must be properly satisfied:
The decommissioning options that are currently available to Operators are numerous and may be visualised with reference to the flowchart below, which serves to show the high-level options for decommissioning of offshore facilities. However, irrespective of the type of plant or facility to be decommissioned, AIE contends that choosing pragmatic approaches are of paramount importance; in this regard, we see derogation as just one of the options that we may propose when devising the most appropriate economic and ecologically acceptable ways in which decommissioning may be accomplished.
AIE works to provide robust but specifically tailored services which help our Clients to proactively manage their planned plant decommissioning works; this serves to provide significant cost savings, improve project efficiency, risk reduction, and maximises safety during the decommissioning process.
We work to solve the significant challenges that will be faced during decommissioning:
We have a long and established track record in the management of facilities integrity, in lifetime extension assessment, of plant mothballing and/or preservation methods and in late life operations; these key service areas are used as the basis for reverse engineering to affect the removal of either individual vessels or systems or entire installations with multiple process systems, ensuring an efficient and smooth process throughout the decommissioning cycle.