Print this pageDetailed Performance Tracking of from Exploration Portfolio Exemplified by Reservoir Statistics
The necessity of performance tracking within exploration is widely recognised and accepted among companies in the oil and gas industry. Still, the problem of too optimistic volume and risk assessments persists. The optimism is probably caused by underrating of the prospects’ volumetric downside and choice of too optimistic most likely cases.
Even when risk and/or volumetric bias have been identified in a company’s portfolio, the problem is difficult to correct for. Statistical analysis of a set of wells may appear unbiased. Yet, subsets of the same wells based on risk classes, prospect types, regions, trap types etc. may reveal optimism or pessimism in pre-drill assessments. Serious biases in smaller sub-sets of the portfolio may not come into light if the detail level in the performance tracking is too coarse. Furthermore, optimism in one sub-set may be crossed out by pessimism in another. Even when a bias has been clearly identified, correcting for it is demanding since the result of the tracking only gives the average deviation from mean, and not the exact answer to how individual prospects should be evaluated.
Thorough investigations of sub-sets of wells as well as individual risk and volume parameters is necessary to detect exactly where in the prospect assessments over-optimism occur, and it is the only means to find out what correcting actions to undertake. Such investigations commonly reveal over-optimism in the assessment of column heights and amount of reservoir. StatoilHydro carries out regular detailed performance tracking on sub-sets of wells and on individual risk and volume factors. StatoilHydro’s applied methodology for detailed performance tracking exemplified by reservoir performance tracking will be the topic of the talk.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil