| Popis: |
Resource volume assessment is an integral part of prospect evaluation. A prospect, in its simplest form, is an unpenetrated reservoir block with seismic data sometimes as the only available data. Hence, a prediction of the most likely hydrocarbon accumulation is required. Recovery factor evaluation for a prospect that has been prognosed via basin modelling to most likely contain non-associated gas (NAG) under high pressure will require an assessment of the abandonment reservoir pressure primarily from analogues or comparable reservoir. The current practice assumes pressure gradient ranges which are then used to estimate the abandonment pressure for the high pressure gas prospectivity evaluation hence it does not take into account the impact of the dynamics of flow (and flow regime). Besides, the assumed pressure gradient ranges may not be robust enough for the evaluation. This paper discusses an approximate methodology to evaluate abandonment reservoir pressure for a high pressure NAG prospect where suitable analogues are not readily available. Two methods were proposedand modelled accordingly using the available seismic data: pressure gradient and pressure sensitivity. The result showed that the pressure gradient modelling approach gave a wider range of recovery factor, wide enough for the resource class maturity. |
