Progress and perspective on the estimation methods for subsurface density distribution in oil and gas exploration: identification of issues in existing exploration schemes and investigation of possible contributions of muography

Abstract

Subsurface density investigation using cosmic ray muons (muography) has been evolving and diversifying its application due to continuous improvement of measurement systems. Investigation of its applicability in oil and gas exploration can promote wider discussion to take forward its application to different promising areas. To increase the reliability and applicability of density information, it is important to identify issues in existing exploration schemes in terms of estimating subsurface density distribution and to investigate possible contributions of muography. This review paper first clarifies the superiority of density information, and then reviews the technical progress of gravity and seismic surveys which have been playing an important role for estimating subsurface density distribution, and finally, based on the reviews, proposes several suggestions to encourage the application of muography to oil and gas exploration.