Improvement Possibilities for the Open Geological Model of the Groningen Field

Abstract

At present, the geological model of the Groningen gas field is one of the largest high-quality open data sets in the oil and gas industry. The purpose of this study is to demonstrate the possibilities of improving the Groningen model, as well as to illustrate some open questions regarding the application of geostatistics in a typical geomodeling workflow in terms of this model.

The model was analyzed, and the analysis showed significant uncertainty in the three-dimensional interpolation of reservoir properties. The properties were modeled using geostatistical simulation; the variability of the modeled parameters was assumed stationary over the entire modeled area. This assumption is not always true even for local objects, and in this case the model covers almost the whole region. The next step was to check whether the variability of the properties was stationary according to the initial data. The verification was carried out using model areas with the size of a area corresponding to that of a typical field.

The main practical result is a demonstration of a way to increase the reliability of the geological model of the Groningen field considered in the study by rejecting geostatistical simulation, which is not applicable in this case, and employing one of the other methods of property propagation instead. Since this model can be used as a basis for various geomechanical simulations necessary to understand the nature of technogenic seismicity associated with the development of this field, ensuring maximum reliability of the model is a very important issue.

Another result of this study is a demonstration of a set of checks necessary to assess the applicability of geostatistical tools. Such a set of checks can be effectively applied in the modeling of any field, both in the course of simulation work to prevent distortions in the model and for examination of existing models. The study showcases the possibility of performing such checks using specialized procedures, as well as with the help of standard geostatistical tools available in most geological modeling packages.

For the first time, the applicability of geostatistical tools in terms of the underlying geostatistical concept of the stationarity hypothesis is considered in detail with a real field serving as the illustration. The study demonstrates the necessary verification tools and considers the issues of compiling the optimal set of such checks.