--> ABSTRACT: Original Gas-in-Place Evaluation for Non-American Gas Shale: The Petroleum System Modelling Supported Approach, by Grigo, Domenico; Galimberti, Roberto; Rodriguez, Elisabetta; #90135 (2011)

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Original Gas-in-Place Evaluation for Non-American Gas Shale: The Petroleum System Modelling Supported Approach

Grigo, Domenico 1; Galimberti, Roberto 1; Rodriguez, Elisabetta 1
(1)eni, San Donato Milanese, Italy.

In the major american Gas Shale basins the Gas in Place volume evaluation can be approached by simply extrapolating the well experimental data (Geochemistry and Logs) due to the intense drilling activity that allows to have available hundreds or more wells. On the other hand in the first phases of a gas shale project evaluation the well data resolution is so low that the normal approach (quantification of well data only) is not enough to describe properly the properties distribution. The extrapolation of well data to the entire prospect extension can be succesfully supported by the numerical simulation of the natural processes governing the properties distribution. Petroleum System Modelling is the only methodology capable to reproduce natural processes starting from well data at basin scale.


Starting from a 3D regional geological model of the area a tentative evaluation of the evolution of the basin is performed with the support of regional restoration in order to define the burial-uplift history. This leads to an original evaluation of maturity parameters that has to be validated against well maturity and temperature data. In the case of non reproducibility a trial and error approach has to be adopted in order to model the necessary thermal peaks. The latter have to be proven by literature data or by elements in the sedimentary sequence that justify the presence of higher past thermal gradients. It is very important in this case to consider not only the maturity data within the Gas Shale interval but also those coming from the entire stratigraphic sequence. This will also help in the definition of the uplift evaluation to confirm the information coming from the structural restoration.

Once these basic features are defined the major gas shale location is identified, but the larger gas shale prospects still have to be located. The information necessary at this point is the regional geochemical-geological model of the source rock. Now the extrapolation of the entire 3D Petroleum System Modelling of the study area can start considering all the processes related to the generation and the expulsion of hydrocarbons.

 

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.