Abstract
The aim of history matching is to minimise the difference between calculated and observed data; An assisted history matching method has been developed where predictions are quantitatively compared to observed seismic and production data and then the model is updated in an objective manner. To improve convergence to suitable solutions, we use a proxy model to understand how parameters control the misfit and then use a global stochastic method such that the random search of the parameter space is biased using derived sensitivities. This maximises the breadth of search offered from stochastic approaches with rapid convergence from gradient type methods. We apply the approach to the Schiehallion field from the west of Shetland. The field has two pre-production and several monitor surveys. We have studied this field previously and use it as a laboratory to apply our new technique. A quadratic regression equation was derived from a representative sample of models and used to generate gradients of the misfit with respect to the parameters. These are used to direct the choice of new models during a random search increasing the chance of finding new models. The new method speeds up the rate of convergence towards better models by a factor of three generally. Suitable models that match observations can be found after running a few hundred models instead of many hundreds. We also tested for the effects of noise in the seismic and production data and these can be minimised. The regression equation itself is of limited use to replace the full misfit calculation but provides excellent sensitivity information. With improved convergence we have the ability run fewer models or search the parameter space more widely. This leads to an improved set or final reservoir models. These in tum can be used more effectively in reservoir management decisions. © 2010, Society of Petroleum Engineers.
Original language | English |
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Title of host publication | Society of Petroleum Engineers - 72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010 - Incorporating SPE EUROPEC 2010 |
Pages | 3094-3108 |
Number of pages | 15 |
Volume | 4 |
Publication status | Published - 2010 |
Event | 72nd EAGE Conference & Exhibition - Barcelona, Spain Duration: 14 Jun 2010 → 17 Jun 2010 |
Conference
Conference | 72nd EAGE Conference & Exhibition |
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Abbreviated title | SPE EUROPEC 2010 |
Country/Territory | Spain |
City | Barcelona |
Period | 14/06/10 → 17/06/10 |