(221b) Geostatistical Inversion Technique for Thin Sandstone Modeling

In the field development stage imaging and well placement for Wara Formation is a very difficult task especially if the reservoir is thin. The objective of this project is to develop the best methodology to model the subsurface and to achieve the objective integration of different data set is required. In this project, a comprehensive study was conducted for the entire Wara Formation to understand the complexity and the distributions of the good quality sandstone reservoir. In order to use the seismic data for quantitative interpretation the workflow should combine seismic, well logs (petrophysics /rock physics) and interpretation. Integration is required because each data has its advantages and disadvantages. Well logs data have a good vertical resolution but limited in the wellbore, however the seismic data is good in spatial distribution but poor in resolution. Geostatistical seismic inversion was used in this project, that resulted in producing set of highly detailed porosity and lithology simulation all are equal probable, unbiased and they are constrained with the input data in this project seismic and logs. The software used in this project is CGG Powerlog for the petrophysics and CGG Jason for the inversion.

Geostatistical tool is proven to be a powerful tool in integrating different data sets to produce the best possible reservoir description. The porosity and lithology 3D model results have been matched with well logs that are not used in the modeling and the output showed a very good correlation. The results showed a promising result that could be used in developing the field.