Fracturing in Basin Models, Application to the Barnett Formation in the Fort Worth Basin, Texas

Sassi, William; Milelli, Laura; Gasparrini, Marta

Petroleum system modelling of geopressure and fracturing has been applied on a US case study of the Barnett Shale Formation. This project evaluates demonstrative workflows for petroleum system modelling of gas shale plays. It combines a study of the mineralized fractures sampled in cored Barnett Shale intervals and a sensitivity analysis of the regional-scale petroleum system and shale gas play of the Fort Worth Basin, north-east Texas. Results provide: (i) the key characteristics of shale fracturing: geometry, spatial distribution, history of fluid movement based on mineralogy, geochemistry and fluid inclusions (i.e. fractures paragenesis from mineralized veins study); (ii) an improved understanding of the key factors controlling the temporal and spatial occurrence of fractures in shale;(iii) recommendations and guidelines to populate basin models with permeability maps according to fracturing episodes

Barnett shale's mineralized fractures in cored intervals of a well found in the gas window, and two others in the oil window, reveal 4 distinct fracturing episodes. The timing of overpressuring modelled in the Fort Worth Basin case study demonstrates the controlling effects of sedimentation rates, kerogen maturation and the key role of the adopted compaction-permeability law. Knowledge of fracture paragenesis established is crucial to calibrate porosity-permeability laws and constrain simulation of hydrofracturing in basin models. A new methodology is proposed to take into account the regional tectonic stress field linked to fracture network and overpressure episodes and study fracture network's impact on estimated remaining gas in place.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013