Rock Physics Analysis of Shale Reservoirs

Abstract

This chapter reviews major developments in rock physics of organic-rich shales (ORSs). First, it brings together available published laboratory measurements on shales including those shales whose total organic carbon (TOC) content is unknown. Next, the chapter reviews experimental and theoretical studies of anisotropic elastic properties of ORSs in connection with their TOC fraction, partial saturation, and maturity. It focuses on the effects of microstructure and maturity on elastic parameters of ORSs. Recent seismic surveys are used to assess the application of the findings of rock physics modeling for predicting the seismic response of ORSs. The chapter discusses an attempt to estimate orientation of vertical fracture sets permeating Bakken Shale from amplitude versus offset and azimuth (AVOAz) data. It presents a study in which the investigated naturally matured samples of the Bakken Shale showed huge differences in mineralogy. These mineralogical differences affect elastic properties and can obscure the effects of maturity.