Schlumberger

Technical Paper: Application of multipoint geostatistics to honor multiple attribute constraints applied to a deepwater outcrop analog, Tanqua Karoo Basin, South Africa

Society: SEG
Paper Number: 2147942
Presentation Date: 2005
 

Abstract

We have used a multipoint geostatistics algorithm called Snesim (Strebelle, 2000) to evaluate its applicability to reservoir modeling. To test the algorithm, we used a data from a deepwater reservoir analog from outcrops in the Tanqua Karoo Basin, South Africa. Our implementation demonstrated the ability of the algorithm to efficiently and faithfully reproduce the texture of geological facies while honoring a large number (127) hard data locations plus rotation and scaling fields and soft probability fields. We have used hand-drawn stationary training images with 3–5 facies to model the proximal to distal facies relationships seen in outcrop. The results show the ability to honor hard data, soft constraints, and complex geological relationships that vary over the reservoir grid. One of the virtues of the Snesim algorithm is its ability to honor multiple soft probability fields when probability distributions overlap; there is no requirement for exclusive categorical membership with sharp cut-offs. This promises to allow better use of seismically derived attribute data for modeling of complex reservoirs.

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