Results 81 to 90 of about 19,864 (265)

Lichens as possible agents of sandstone deterioration in Jesuitic ruins of San Ignacio Miní (Misiones Province, Argentina)

open access: yesMateriales de Construccion, 2010
The ruins of San Ignacio Miní, in NE Argentina, Misiones Province, included by the UNESCO in the list of World Heritage in 1984, were built in the 18th century by the Guarani people under the supervision of the Jesuite Congregation. The ruins are located
V. G. Rosato
doaj   +1 more source

Dynamic tensile strength and fracture evolution of characteristic shale with bedding and hole using linear regression theory

open access: yesDeep Underground Science and Engineering, EarlyView.
The spiral conical perforations generated during methane in situ explosion fracturing operations lead to tensile fracture propagation in shale reservoirs being governed by the combined effects of impact pressure, bedding, and aperture under explosive loading. Using multiple regression analysis and digital image correlation technology, the mechanisms of
Yabo Chai   +7 more
wiley   +1 more source

Semi‐analytical solution for the stability of deep vertical shaft considering time‐dependent rock‐structure interaction

open access: yesDeep Underground Science and Engineering, EarlyView.
A novel cavity contraction solution and multilayer shaft wall model were developed to analyze deep shaft stability, considering rock viscosity, support structures, and water pressure, with successful validation through a Hulusu Coal Mine case study.
Bin Chen   +5 more
wiley   +1 more source

Multiple injection techniques to stimulate complex fracture networks in coal reservoirs: A case study on gas disaster reduction of subsurface coal mine in southwest China

open access: yesDeep Underground Science and Engineering, EarlyView.
An experimental device for physical simulation of hydraulic fracturing, comprising: a load‐bearing mechanism with multiple interconnected plates that collectively form an sample chamber; a load‐generating mechanisms, with multiple load‐generating mechanisms arranged within the experimental chamber.
Delei Shang   +5 more
wiley   +1 more source

Surface hydration‐induced damage in tight oil‐bearing sandy conglomerate reservoirs

open access: yesDeep Underground Science and Engineering, EarlyView.
A series of techniques such as X‐ray diffraction, scanning electron microscopy, energy‐dispersive spectroscopy, conductivity tests, and infrared thermal imaging were used. The key findings are the identification of a two‐stage surface hydration process and the elucidation of the effects of various minerals and elements on the hydration process ...
Anbang Zhao   +5 more
wiley   +1 more source

Sources of Sandstone [PDF]

open access: yesNature, 1872
YOUR geological readers will readily admit the importance of any hint that will assist them in determining the source from which a particular bed of sand or sandstone has been derived.
openaire   +2 more sources

The impact of forced closure on proppant distribution of hydraulic fracturing in shale formations

open access: yesDeep Underground Science and Engineering, EarlyView.
Research findings demonstrate that implementing forced closure within shale formations can remarkably mitigate proppant settlement, concurrently increasing the effective propped surface area from 29.74% to 38.68%. Abstract Forced closure is widely used in conventional oil and gas reservoirs to promote uniform proppant placement.
Tongxuan Gu   +3 more
wiley   +1 more source

Gaborlet‐guided sparse filtering: A novel intelligent method for lithology identification by vibration signals while drilling

open access: yesDeep Underground Science and Engineering, EarlyView.
The flowchart illustrates rock specimen testing, vibration signal acquisition, and feature extraction with Gaborlet and sparse filtering for classification. Abstract Traditional lithology identification methods mainly rely on core sampling and well‐logging data.
Jian Hao   +5 more
wiley   +1 more source

Fracture evolution of a thick soft protection layer and the water inrush mechanism in overburden under longwall mining

open access: yesDeep Underground Science and Engineering, EarlyView.
Through shear–tensile creep tests and viscoelastic modeling, the fracture evolution of thick soft protective layers is clarified. Results show thickness‐dependent rheological failure modes that govern four types of roof water inrush, providing a mechanism‐based framework for hazard prediction and control. Abstract In the Jurassic coal‐bearing strata of
Mengnan Liu   +4 more
wiley   +1 more source

Mechanistic insights across curing regimes for enzymatic and biopolymer‐optimized reinforcement in rock masses

open access: yesDeep Underground Science and Engineering, EarlyView.
This study examines the effects of curing temperature on the mechanical behavior of underground rock masses treated with enzyme‐induced calcite precipitation (EICP) and an innovative biopolymer‐modified EICP (BP‐EICP). Abstract Biocementation is an innovative and sustainable technique for reinforcing weak and weathered rock masses in natural and ...
Mary C. Ngoma, Oladoyin Kolawole
wiley   +1 more source

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