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A predictive anisotropic rock physics model of shale and its practical applications

Event Type

Event Date

Thursday, October 20, 2022

Event Location

Event Address

Zoom

Event Start

1400

Event End

1530

Event Details

Title: A predictive anisotropic rock physics model of shale and its practical applications

Presenter: Dr. Michinori Asaka

Date: Thursday, 6th October 2022

Time: 1400 - 1530 AWST

Registration: https://us02web.zoom.us/webinar/register/WN_aHzlwiLpRRy6hKzdpx_JRw

Abstract:

Elastic response of rocks often depends on the rock’s orientation, i.e., most rocks are anisotropic. In particular, shales which are the overburden rock in most of conventional oil and gas fields, often show strong elastic anisotropy due to alignment and platy nature of its constituent mineral. Various anisotropic rock physics models have been proposed to predict the elastic anisotropy of shales, however, practical applications are limited and most of rock physics models in the past do not follow the observed internal structure of shales and bound water properties suggested by existing studies. A predictive rock physics model of shale is developed by combining existing theories. Properties of locally aligned clay platelets, called domains, are calculated using a model based on the anisotropic Hashin-Shtrikman estimates. The effect of domain orientation is then accounted for by the orientation distribution function of domains. This model is consistent with the observed internal structure of shales and allows the finite shear stiffness of bound water to be taken into account. The applicability of the model was investigated using existing core measurements. The results imply that the model can be used to predict anisotropy parameters from limited information. 

Bio:

Michinori Asaka started his career as a geophysicist with INPEX in 2009. He worked for various geophysical problems including AVO analysis/inversion, rock physics, 4D seismic feasibility study, structural interpretation, and depth conversion. In 2018, he joined the PhD programme in Geophysics at Norwegian University of Science and Technology, Trondheim, Norway. He completed his thesis focusing on practical applications of elastic anisotropy in rock physics, rock mechanics and seismic reservoir characterization in 2022. He is currently working for INPEX where he continues working on reservoir characterization.