Technical Paper
Reliability Analysis Spanning Whole Well Life

Proneta ltd (UK); SPE 78326; SPE 13th European Petroleum Conference held in Aberdeen, Scotland, U.K., 29-31 October 2002.

Abstract

Reversionary Mode Analysis (RMA) was used to analyse the reliability of the whole life-cycle of a proposed well development, so that the risks associated with different well designs could be quantitatively compared. The technique combines engineering analysis and economic modelling in a systematic and rigorous way. For this project, we needed to extend the economic aspects, to match the level of detail used in the business case economics for this field development.

RMA is an innovative and powerful system analysis technique that has been adapted from its aerospace origins for application in oil and gas projects. The engineering aspects, founded on conventional failure mode analysis methods, were already well developed.

The process started with engineering analysis of the failure modes, determining cause, effect and probability. To ensure proper coverage of the whole life-cycle, RMA handles both activities, defined by process flow diagrams, and equipment defined by system block diagrams. To confirm the validity of the analysis, the estimated probabilities of failure were checked with alternative sources.

Then an economic model was produced, quantifying in financial terms the consequences of a whole range of different types of failure. The analysis software consolidated all the failure mode data with the economic model.

The results in ‘risk-Dollars’ highlighted the aspects that are critical to the project’s viability, and provided a good basis for comparing different well options. The rigorous data structure provided the capability to ‘drill-down’ into critical aspects, to identify key causes for which mitigating measures were needed, which may occur at any stage in life-cycle.