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Abstract Until the offshore industry stepped off the continental shelf, the main marine geohazard risk addressed from geophysical data was the presence of shallow gas. Presence had been described using a number of non-standard approaches for its potential presence – distinct from the actual risk it presented to operations. In the 1990 “UKOOA Guidelines for the Conduct of Marine Rig Site Surveys,” a standardised nomenclature was suggested that was largely taken up as a standard by the industry.
At around this point in time, the industry had begun a move off the shelf and into deep water and, with this, a number of new geohazard issues started to present themselves (e.g. shallow water flow, chemosynthetic communities, hydrates and slope instability) for which the industry had no standard approach to assess the risk such hazards presented or to reliably define their presence.
Today the industry is faced with entry into frontier areas, with little prior published understanding, potentially complex slope and deep-water settings, and where the sources of geohazard risk to drilling and developments may be multiple, over printed, and inter-related.
In such settings, early effort in the exploration and production cycle is required to allow appropriate data to be gathered and assessed in appropriate time for drilling and facilities engineers either to avoid identified hazards, or mitigate their presence through appropriate engineering design.
In order to address these issues, BP has adopted a methodology to manage geohazard risks over the “Life of Licence,” starting with assessments of fundamental geohazard complexity and manageability on entry to a frontier area, at the basin or fairway scale, and thence defining an ongoing work programme to support continued refinement in understanding through to and including the abandonment phase.
This includes:
Suggested specific risking criteria for the presence of individual geohazard elements at a well location such that engineers can clearly, and consistently, understand potential hazard presence,
Early definition of required data acquisition needs and integrated studies for field development to adopt appropriate risk mitigation methods in engineering design,
Through the Operate phase of a field and on to eventual abandonment a system to address lessons and changes are noted with documents regularly updated ahead of additional drilling, field development, or abandonment activities.
The paper will present, and illustrate, the rationale adopted by BP showing examples of outputs produced along the process path, to demonstrate how the approach is delivered in practice.
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