Imaging Unconventional Reservoir Pore Systems

This Memoir covers recent advances in the acquisition and application of high-resolution image data to unconventional reservoirs. The value of integrating multiple techniques is a common theme. Chapters address imaging methods, recognition of artifacts, and case studies that explore nanopore systems within particular depositional settings. The importance of mineralogy, organic matter content, and fabric to reservoir quality issues such as wettability, porosity, and formation damage are addressed. This volume will prove useful to anyone interested in the methods for observing and quantifying the pore systems that control hydrocarbon storage and flow in unconventional reservoirs. Unconventional reservoirs studied include Bakken, Barnett, Bossier, Eagle Ford, Geneseo, Green River, Horn River, Marcellus, Mississippi Lime, Monterey, Niobrara, Wolfcamp, and Woodford formations.
Correlative X-ray and Electron Microscopy for Multi-scale Characterization of Heterogeneous Shale Reservoir Pore Systems Available to Purchase
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Published:January 01, 2016
Abstract
The complexity of unconventional reservoirs is manifested both in compositional variance of the matrix and the vast heterogeneity of the pore geometry. These complications confound proper understanding of transport properties and, consequently, recoverability for all stages in the production life cycle. Imaging techniques have emerged as a technical solution to aid how we decipher these complexities at the appropriate scales. In this study, we use the Woodford Shale as a representative of a commercially viable unconventional reservoir, and we apply multi-scale imaging analytics to a core sample. Our observations across four different length scales from imaging results of micro-x-ray microscopy (micro-XRM), nano-x-ray microscopy (nano-XRM), and focused ion-beam scanning electron microscopy (FIB-SEM) demonstrate both heterogeneity and anisotropy at every scale. We describe our multi-scale imaging workflow, which proved necessary to capture the multi-scale variability. In this instance of siliceous type II source rock, we find that micro-XRM was insufficient to visualize porosity, nano-XRM was sufficient for visualization of only limited porosity, whereas FIB-SEM yielded the resolved pore network. We further find that discrimination of the pore types, with the aid of image segmentation, helps define the connectivity and nature of the transport system. Collectively, the application of imaging across scales with appropriate image processing is required to adequately understand the transport-governing microstructure.
- Anadarko Basin
- applications
- characterization
- Devonian
- electron microscopy data
- geometry
- heterogeneity
- heterogeneous materials
- matrix
- mechanical properties
- microstructure
- mineral composition
- organic compounds
- Paleozoic
- petroleum
- porosity
- reservoir rocks
- segmentation
- SEM data
- shale oil
- thermal maturity
- United States
- variations
- Woodford Shale
- X-ray data