Depositional-process controls on chemofacies in mixed-lithology submarine lobe deposits: a high-resolution core study from the Permian Wolfcamp XY Formation, Delaware Basin, Texas, U.S.A. DOI

Shaskia Herida Putri,

Zane Jobe,

Jesse Melick

et al.

Journal of Sedimentary Research, Journal Year: 2025, Volume and Issue: 95(1), P. 63 - 85

Published: Jan. 30, 2025

ABSTRACT Mixed siliciclastic–carbonate mudrocks have variable depositional processes and diagenetic pathways, creating mineralogical complexity thus difficulty in characterizing reservoir quality using typical subsurface datasets (e.g., well logs) as conventional visual core-description techniques. Core-based X-ray fluorescence (XRF) data quantifies subtle elemental variations that can aid interpreting fine-scale sedimentological packages reservoir-property distribution. XRF has proven to be particularly useful for defining the of muddy, thin-bedded, mixed-lithology successions like Wolfcamp Bone Spring formations Delaware Basin, Texas, USA. These units consist early middle Permian siliciclastic carbonate deep-marine deposits form productive unconventional hydrocarbon reservoirs. However, spatial temporal variability evolution leads predicting presence quality. Several studies utilized core-based this purpose, but not at a resolution sufficient capture true heterogeneity these thin-bedded deposits. Using continuous, high-resolution (1 cm, 0.39 inch) from 66 m (218 feet) core associated geomechanical well-log XY interval, study demonstrates chemofacies derived unsupervised machine learning correlate with event-bed interpretations Unsupervised k-means clustering principal-component analysis on 17 XRF-derived concentrations derive four characterize geochemical heterogeneity: 1) calcareous, 2) detrital, 3) oxic–suboxic argillaceous, 4) anoxic argillaceous. The mineralogy paragenesis are validated scanning-electron microscopy (SEM) thin-section petrography. Vertical XRF-based accurately represent facies changes hybrid-event-bed boundaries, often matching cm-by-cm visually-described lithofacies. We utilize detailed dataset construct predictive model linking sediment routing sources various properties. This research also properties total organic carbon, porosity, permeability, water saturation) response (brittleness unconfined compressive strength) vary chemofacies, argillaceous generally being less brittle having higher porosity. results used log-based prediction other mixed deep-water reservoirs around world.

Language: Английский

Depositional-process controls on chemofacies in mixed-lithology submarine lobe deposits: a high-resolution core study from the Permian Wolfcamp XY Formation, Delaware Basin, Texas, U.S.A. DOI

Shaskia Herida Putri,

Zane Jobe,

Jesse Melick

et al.

Journal of Sedimentary Research, Journal Year: 2025, Volume and Issue: 95(1), P. 63 - 85

Published: Jan. 30, 2025

ABSTRACT Mixed siliciclastic–carbonate mudrocks have variable depositional processes and diagenetic pathways, creating mineralogical complexity thus difficulty in characterizing reservoir quality using typical subsurface datasets (e.g., well logs) as conventional visual core-description techniques. Core-based X-ray fluorescence (XRF) data quantifies subtle elemental variations that can aid interpreting fine-scale sedimentological packages reservoir-property distribution. XRF has proven to be particularly useful for defining the of muddy, thin-bedded, mixed-lithology successions like Wolfcamp Bone Spring formations Delaware Basin, Texas, USA. These units consist early middle Permian siliciclastic carbonate deep-marine deposits form productive unconventional hydrocarbon reservoirs. However, spatial temporal variability evolution leads predicting presence quality. Several studies utilized core-based this purpose, but not at a resolution sufficient capture true heterogeneity these thin-bedded deposits. Using continuous, high-resolution (1 cm, 0.39 inch) from 66 m (218 feet) core associated geomechanical well-log XY interval, study demonstrates chemofacies derived unsupervised machine learning correlate with event-bed interpretations Unsupervised k-means clustering principal-component analysis on 17 XRF-derived concentrations derive four characterize geochemical heterogeneity: 1) calcareous, 2) detrital, 3) oxic–suboxic argillaceous, 4) anoxic argillaceous. The mineralogy paragenesis are validated scanning-electron microscopy (SEM) thin-section petrography. Vertical XRF-based accurately represent facies changes hybrid-event-bed boundaries, often matching cm-by-cm visually-described lithofacies. We utilize detailed dataset construct predictive model linking sediment routing sources various properties. This research also properties total organic carbon, porosity, permeability, water saturation) response (brittleness unconfined compressive strength) vary chemofacies, argillaceous generally being less brittle having higher porosity. results used log-based prediction other mixed deep-water reservoirs around world.

Language: Английский

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