Digital core analysis: Improved connectivity and permeability characterization of thin sandstone layers in heterolithic rocks

Heterolithic thin beds reservoirs contain significant amounts of hydrocarbons. We characterized the reservoir properties (sandstone connectivity, continuity and permeability) of sandstone layers in heterolithic rocks using three-dimensional imaging and analysis of heterolithic core plugs and mini plugs. The high-resolution three-dimensional models of the samples are smaller than a typical reservoir model grid block and similar the millimetre-to-centimetre beddings in heterolithic rocks. We find that the key to reservoir quality in heterolithic rocks is the connectivity and continuity of thin reservoir sandstone layers. Also, we show that these well connected and continuous thin sandstone layers have higher effective permeabilities that are comparable to a reference reservoir sandstone. These results can provide further information as to why some low resistivity heterolithic intervals with low net-to-gross values of the sandstone produced a significant amount of hydrocarbon despite lower production forecast based on well logs and core plug data. Determining the connectivity and continuity of thin sandstone layers is difficult due to limitations of well logs and core plug analysis that do not resolve and capture the connectivity of thin beddings. We show that 3-D Image Visualization is effective in characterizing the connectivity and continuity of thin sandstone layers in heterolithic rocks. Also, our Digital Core Analysis method computed permeability of thin sandstone layers in 3-D models of mini plugs representing thin sandstone layers in heterolithic core plugs. Our results represent information and reservoir properties at the millimetre-to-centimetre scale that are similar to the thickness of thin sandstone beddings in heterolithic rocks.The study was supported by the Universiti Malaya Research Grant RP031A-15AFR and FP045-2017A and was conducted at the Australian National University under a Dual PhD program arrangement with Universiti Malaya. PETRONAS, the Malaysian National Oil Company, is acknowledged for providing the core samples used in this stud

Pharmacological inhibition of endoplasmic reticulum stress mitigates osteoporosis in a mouse model of hindlimb suspension

Abstract Hindlimb suspension (HLS) mice exhibit osteoporosis of the hindlimb bones and may be an excellent model to test pharmacological interventions. We investigated the effects of inhibiting endoplasmic reticulum (ER) stress with 4-phenyl butyrate (4-PBA) on the morphology, physicochemical properties, and bone turnover markers of hindlimbs in HLS mice. We randomly divided 21 male C57BL/6J mice into three groups, ground-based controls, untreated HLS group and 4-PBA treated group (HLS+4PBA) (100mg/kg/day, intraperitoneal) for 21 days. We investigated histopathology, micro-CT imaging, Raman spectroscopic analysis, and gene expression. Untreated HLS mice exhibited reduced osteocyte density, multinucleated osteoclast-like cells, adipocyte infiltration, and reduced trabecular striations on micro-CT than the control group. Raman spectroscopy revealed higher levels of ER stress, hydroxyproline, non-collagenous proteins, phenylalanine, tyrosine, and CH2Wag as well as a reduction in proteoglycans and adenine. Furthermore, bone alkaline phosphatase and osteocalcin were downregulated, while Cathepsin K, TRAP, and sclerostin were upregulated. Treatment with 4-PBA partially restored normal bone histology, increased collagen crosslinking, and mineralization, promoted anti-inflammatory markers, and downregulated bone resorption markers. Our findings suggest that mitigating ER stress with 4-PBA could be a therapeutic intervention to offset osteoporosis in conditions mimicking hindlimb suspension