purpose: to determine the prevalence of intraocular injuries in patients with blow-out fracture and also to evaluate the etiologic mechanism of orbital blow-out fractures methods: this study is a consecutive case series analysis of 116 patients with orbital blow-out fractures. the patients were visited by an ophthalmologist within 24 hours of trauma. results: ninety-one men and twenty-five wome...

An infinite elastic medium with a planar crack is considered. The crack is subjected to the pressure of fluid injected at a point on the crack surface. Description of the crack growth is based on the lubrication equation (balance of the injected fluid and the crack volume), the equation for crack opening caused by fluid pressure on the crack surface, the Poiseuille equation related local fluid ...

The morphological control of the fracture has a great impact on the effectiveness of the hydraulic fracturing; the geostress difference between productive interval and barriers is one of controlling factors for the fracture height control. The propagation behavior of the hydraulic fracture was studied using the 3D physical simulation under conditions of the presence and absence of the interlami...

We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, based on the finite element method for geomechanics. The T+M simulator can model the initial fracture development during the hydraulic fracturin...

This paper develops a closed-form approximate solution for a penny-shaped hydraulic fracture whose behaviour is determined by an interplay of three competing physical processes that are associated with fluid viscosity, fracture toughness and fluid leak-off. The primary assumption that permits one to construct the solution is that the fracture behaviour is mainly determined by the three-process ...

Reservoir simulators remain essential tools for improved reservoir management in order to optimize hydraulic fracturing design in unconventional low permeability reservoirs. However, the commonly-used simulator requires too much computational efforts for the description of local phenomena in the vicinity of the hydraulic fractures, and is practically infeasible for field applications, due to la...

Hydraulic fracturing treatments are often monitored by strings of geophones deployed in boreholes. Instead of picking discrete events only, we here use time-frequency representations of continuous recordings to identify resonances in two case studies. This paper outlines an interpretational procedure to identify their cause using a subdivision into source, path, and receiver-side effects. For t...

The generalized conceptual model for a fractured bedrock aquifer consists of low-permeability matrix blocks separated by highly permeable fractures that act as preferential pathways for ground water flow. The National Research Council (NRC 1996) summarizes three approaches for simulating ground water flow in fractured aquifers. The most common approach is to represent the system with an equival...

Abstract The shale gas reservoir is regarded as a dual medium consisting of fracture (hydraulic and discrete natural network) rock matrix, the seepage process in matrix fully considered mathematical model flow accordance with Darcy's law was established. results show influence order hydraulic geometry on cumulative production. Compared aperture 10 –4 m, when –5 m –6 production reduced by 88.0% ...

    The combination of horizontal drilling along with hydraulic fracturing has significantly improved the production of hydrocarbon reservoirs and made it possible to extract the relatively impermeable and uneconomical reservoirs. The production rate of oil and gas wells increases proportional to hydraulic fracture aperture or crack opening displacement (COD). This is an important parameter i...