Integrated Seismic Approach and Key Technologies for Shale Gas Characterization
Quantitative seismic interpretation workflows are still immature for shale gas reservoirs compared to QI applications for conventional carbonate and clastic reservoirs. However, surface seismic data and microseismic have proven to be an invaluable asset for organizations producing hydrocarbons from unconventional resource plays. More recent advances in pre-stack seismic data analysis yield attributes that appear to correlate to lithology, rock strength and stress fields in the formation. Knowledge and proper utilization of these attributes may prove valuable in the optimization of drilling and completion activities. In this paper we show an integrated seismic approach based on pre-stack azimuthal seismic data analysis, microseismic and well log information to identify "sweet spots", estimate geomechanical properties and in-situ principal stresses. In this paper we will also highlight how key technologies like the orthorhombic migration, 5D interpolation and azimuthal inversion are used in shale gas characterization.
Properties such as Young’s Modulus and Poisson’s ratio may provide valuable information for facies identification, mineral content, and rock strength. From these, we may infer preferential "sweet spots". Additionally, analysis of differential horizontal stress may be calibrated to field observations yielding stress field predictions such as fracture initiation pressure and closure pressure valuable during the completion stage of the fracture stimulation process. The reliability of these estimates has been addressed by incorporating triaxial core measurements and microseismic data.
AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013