Formation of conical fractures in sedimentary basins ...

Large sand intrusions often exhibit conical morphologies analogous to magmatic intrusions such as saucer-shaped or cup-shaped sills. Whereas some physical processes may be similar, we show with scaled experiments that the formation of conical sand intrusions may be favoured by the pore-pressure gradients prevailing in the host rock before sand injection.

Geology of Kentucky: Chapter 23, Petroleum and Natural Gas

2008-2-4 · The rock is a fine-grained sandstone, often red-purple in color, and intercallated with red shales. It occurs just below the Big Lime, in the upper Waverly (Pocono of West ia). On the basis of shale partings, three pays are locally …

Formation of conical fractures in sedimentary basins ...

Highlights We mechanically explain the tripartite architecture of sand intrusion complexes. We produce conical hydraulic fractures in experiments involving pore fluids. Fractures grow vertically until a critical depth where two dipping wings form. The inclined fractures open in mixed mode before transforming into fine shear bands. Shear bands induced by deformation of the cover provide ...

STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES 1 ...

2006-3-19 · consists of squeezing pieces of rock diametrically between two hardened steel cones. The test set-up is shown in Figure 1. For these tests, rock pieces must have a length at least 1.4 times their diameter (Figure 2a). The point load index, Id, is equal to where P is the load at rupture and D is the core diameter. Rock specimens break since tensile

Formation of conical fractures in sedimentary basins ...

 · Large sand intrusions often exhibit conical morphologies analogous to magmatic intrusions such as saucer-shaped or cup-shaped sills. Whereas some physical processes may be similar, we show with scaled experiments that the formation of conical sand intrusions may be favoured by the pore-pressure gradients prevailing in the host rock before sand injection.

Hydraulic Bursting Of Concrete And Rock | U.S. Rock ...

Hydraulic Bursting Of Concrete And Rock William C. Cooley. William C. Cooley Terraspace, Inc. Search for other works by this author on: This Site. Google Scholar. Paper presented at the 19th U.S. Symposium on Rock Mechanics (USRMS), Reno, Nevada, May 1978.

TEMPORAL VARIATIONS IN A FRACTURE CONTROLLED …

2013-3-27 · Sandstone denuded during a Lake Iroquois breakout. The site is ideally suited for the study of fracture flow hydrology because of the lack of over burden. One can clearly document the orientation and density of fractures exposed on the bedrock surface and cliff faces. We have over 25 wells at the site used for the study of fracture-flow hydrology.

Lithological control on fracture cementation in the Keuper ...

The spatial arrangement of gypsum veins as preserved natural hydraulic fractures have been characterized in the Triassic Keuper Marl Formation (UK), a caprock for hydrocarbon reservoirs and CO 2 sequestration. The marls cropping out are subdivided into five discrete fracture units based on the presence and abundance of gypsum veins.

Modified Fracture Mechanics Approach for Hydraulic ...

2020-12-4 · Hydraulic fracturing (HF) test has been widely used to determine in situ stress. The use of a conventional continuum method for this purpose has raised considerable controversies concerning field tests, particularly in the determination of the maximum horizontal principal stress under preexisting fractures. Fracture …

Hydrodynamic analysis of clastic injection and hydraulic ...

2011-12-11 · a) consists of purple siltstone, silty fine sand-stone, and fine sandstone, while the upper member (E 1y b)is composed of gray and reddish fine sandstone and gravelly sand-stone in the west and breccia near the Pijiang Fault in the east (Fig. 3b). Above the E 1y is the E 2g that is composed of purple muddy sandstone, siltstone and gypsum.

Fracture Processes of Rocks In Dynamic Tensile-splitting ...

1st Canada - U.S. Rock Mechanics Symposium May 27–31, 2007 Vancouver, Canada All Days. Previous Paper; Next Paper; Article Navigation Fracture Processes of Rocks In …

Damage and Fracture Behavior of Rock

2019-5-2 · Damage and Fracture Behavior of Rock. Hang Lin,1 Ri-hong Cao,1,2,3 Xiang Fan,3,4 and Yixian Wang 5. 1School of Resources and Safety Engineering, Central South University, Changsha, Hunan 410083, China. 2School of Civil, Environmental and Mining Engineering, The University of Western Australia, Perth 6009, Australia.

An Improved Fracability-Evaluation Method for Shale ...

2017-10-13 · The new fracability model takes into account the brittleness, fracture toughness, and minimum horizontal in-situ stress of the gas-shale reservoirs. Compared with the previous models, the new model has better resolution in identifying fracability. The accuracy of the proposed model is verified with the efficiency of field hydraulic-fracturing jobs.

Three-dimensional measurement of fractures in ...

Fractures and fracture networks are three-dimensional (3D) features that have 3D effects on the flow properties of natural materials. Because fractures are characteristically rough and uneven, flow through them tends to follow a meandering path of least resistance defined by local pressure gradients, which are in turn largely determined by the fracture topology, in particular variation in ...

Mechanical Properties of Intact Rock and Fractures in ...

2012-1-21 · Therefore, the mechanical and hydraulic properties of intact rock and jointed rock are needed. To obtain the required mechanical properties of intact rock and rock joints, it is necessary to measure the properties in the field or laboratory tests. Triaxial compression and shear tests are commonly used for

Resistance of caprock to hydraulic fracturing due to CO2 ...

2013-9-17 · The geomechanical stability of caprock is critical to the long-term safety of geologic storage of CO 2 in depleted oil reservoirs. Based on the theory of rock fracture mechanics in deep formations, we propose a quantitative assessment framework for the resistance of caprock to hydraulic fracturing due to CO 2 injection and storage in a sand lens reservoir.

Numerical investigation of the hydraulic fracturing ...

2021-4-1 · This model has been calibrated against triaxial experiments. Further description of the model parameters and the detailed calibration process can be found in Taghipoor, Roostaei, Nouri, and Chan (2014).A cohesive constitutive model (Barenblatt, 1962) is used to calculate the tensile strength of the material is assumed that before fracturing, the rock undergoes linear softening under tension ().

Li ZHUANG | Researcher | PhD | Korea Institute of Civil ...

Berea sandstone in northern Ohio is a transversely isotropic rock. X-ray CT investigations showed that its internal structure is composed of cross-bedded loose layers and …

D. BUREAU | Lecturer | PhD | Université du Maine, Le Mans ...

Like igneous intrusions, sandstone intrusions exhibit geometries such as dykes, sills, cone- and saucer-shaped or wings. To form, these features require hydraulic fracturing of the overburden ...

Natural Rock Fractures: From Aperture to Fluid Flow ...

2021-8-7 · Fractures provide preferential flow paths that define the rock mass internal "plumbing", especially in low matrix-permeability rocks. Therefore, the rock mass hydraulic response results from the fracture density, orientation, and the stress-sensitive fracture transmissivity (Barton et al. 1995; Zimmerman and Bodvarsson 1996) turn, fluid conduction in fractured rock masses affects the ...

Mechanical Parameters Controlling Sandstone Intrusion ...

Like igneous intrusions, sandstone intrusions exhibit geometries such as dykes, sills, cone- and saucer-shaped or wings. To form, these features require hydraulic fracturing of the overburden, fluidization and injection of depositional sand into the contemporaneous fracture network.

Effects of Confining Stresses, Pre-crack Inclination ...

2019-11-16 · Tang SB, Zhang H (2016) Hydraulic fracture prediction theory based on the maximum tangential strain criterion. Chin J Rock Mech Eng 35(suppl 1):2710–2719. Google Scholar Teufel LW, Clark JA (1981) Hydraulic fracture propagation in layered rock: experimental studies of fracture containment. SPE J 24(1):19–32

Shale Anisotropy and Natural Hydraulic Fracture ...

2020-2-5 · 1 Introduction. Hydraulic fracturing in shale is important for the sealing capacity of shale layers during natural (Foschi et al., 2018; Petrie et al., 2014) and artificial (Elkhoury et al., 2015) fluid‐expulsion events.The mechanical anisotropy of shale is evident from its fissility in hand samples, from abundant examples of layer‐parallel natural fractures hosted in shales worldwide ...

Features of fracture height propagation in cross-layer ...

2021-4-1 · The hydraulic fracture propagates in a stripe shape vertically in both sandstone and shale layers, but it spreads in the plane in shale layers after connecting beddings. Restricted by beddings, the hydraulic fractures in shale layers are smaller in height than those in sandstone layers.

Coupled hydro-mechanical evolution of fracture ...

2020-12-15 · The increase of fluid mixture pressure in the basal sandstone formation results in vertical fracturing and growth in Mode I failure. Shear bands develop in the fracture branch in the upper inclined dyke zone in a mixed mode of shear-tension failure. Q. Gan et al. / Journal of Rock Mechanics and Geotechnical Engineering 12 (2020) 742e751 743

Fracture (Frac) Sands in Kentucky, Kentucky Geological ...

2019-9-13 · Fracture (Frac) Sands in Kentucky General Information. Sandstone suitable for use in hydraulic fracture well treatments (frac sands) are in high demand due to the shale gas revolution in the U.S. Shale reservoirs are stimulated for oil and gas …

Special Topics in Natural Fracture Development: Hybrid ...

vertical growth of hydraulic fractures. Hybrid fractures. There is a large volume of rock mechanics literature addressing the development of shear fractures and extension fractures. A number of authors have proposed the existence of hybrid fractures that have attributes of both extension and shear fractures (e.g. Hancock, 1985).

Assessing the role of fractures on the permeability of the ...

2018-7-1 · The influence of open fracture space on rock permeability is often assessed using the cubic law (Witherspoon et al., 1980; Tsang, 1984; Pyrak-Nolte et al., 1987; Zimmerman and Bodvarsson, 1996), which models the permeability of a fracture as k f = d 2 12, where d is the fracture aperture. The cubic law models laminar fluid flow between smooth ...

Introduction to Groundwater Science

2019-1-28 · • Porosity - the percentage of rock or sediment that consists of voids or openings – Measurement of a rock''s ability to hold water – Loose sand has ~30-50% porosity – Compacted sandstone may have only 10-20% porosity • Permeability - the capacity of a rock to transmit fluid through pores and fractures – Interconnectedness of pore ...

StabilityAssessmentofDangerousRockMassofanOverhanging ...

2021-7-6 · rock mass and classified the collapse types into shear-fall, tension-break, fall-fall, tipping-collapse, crushing and cav- ... maximum circumference stress fracture criterion and maximum shear stress fracture criterion, and deduced the ... purple gray sandstone interbedded with purplish red mud-

Chapter 4 Engineering Classification of Rock Materials

Table 4–13 Fracture type 4–21 Table 4–14 Fracturing density description chart 4–21 Table 4–15 Joint set spacing categories 4–22 Table 4–16 Aperture category 4–23 Table 4–17 Joint infilling 4–24 Table 4–18 Joint persistence categories 4–25 Table 4–19 Types of joint ends 4–25 Table 4–20 Descriptors for weathering condition of joint face rock 4–27