Background
An E&P Company operating in the North Sea realised that prospect risk and success volume ranges were not being consistently predicted. This aligned with an overall industry trend wherein calibrating forecasts and results was becoming increasing difficult. Their assessment concluded that in many cases, the chance of success for the entire prospect segment, e.g. a fault block, was being taken as the chance of success for the well targeting that segment. The company was attempting to address this complexity with a tedious spreadsheet-based workaround, disconnected from their standard prospect assessments.
Specific Challenges
The company realised that, for a given oil-containing prospect, the well might encounter only gas (too much updip) or water (too much downdip), missing the oil zone. This is particularly relevant for thin reservoirs, in the presence of gas, with seal-limited accumulations (not filled to spill point). Well risk can be equal to prospect risk (in best case), but often, as it varies along the flank of the structures
Solution
In the Ariane software, every probabilistic simulation of prospect risk and volume is logically followed by a well risk and volume analysis. Depending on the “penetration window” of the well, the outcome could be an oil discovery, a gas discovery or a dry hole. Using Ariane, exploration wells can be dynamically planned and locations chosen to optimise risk-reduction and find proven volumes.
Outcome
Implementing Ariane enabled the error-prone workaround to be effortlessly integrated into the operator’s prospect assessments. Further implementation lead to tangible gains in efficiency, transparency and integrity of results.