Hydraulic fracturing and matrix stimulation are two major methods of the reservoir stimulation. Hydraulic fracturing, which is the newest technique and technically more complex, is very useful in low permeability reservoirs. Although it has been used widely in hydrocarbon production wells, it is a new method in Iran. In this paper, the effect of sufficient barrier layers on hydraulic fracturing...

a r t i c l e i n f o Keywords: Concrete (E) Fiber reinforced concrete (FRC) (E) Constitutive relationship (C) Cohesive fracture (C) Fracture energy (C) A simple, effective, and practical constitutive model for cohesive fracture of fiber reinforced concrete is proposed by differentiating the aggregate bridging zone and the fiber bridging zone. The aggregate bridging zone is related to the total...

Fracture mechanics is a field of solid mechanics interested with the behaviour of materials under certain loads their distribution and finally the fracture criteria of given materials.This Paper evaluates size dependency of fracture parameters, fracture energy (Gf) and fracture process zone effective length (Cf) of concrete concluded as per Bazant’s size effect method. Fracture mechanics standa...

in order to investigate the role of multi-wall carbon nanotubes (mwcnts) on fracture mechanism of epoxy nanocomposites, a series of tensile standard specimens reinforced with different carbon nanotube contents (0, 0.3, 0.6 and 1 wt%) were produced. the fracture surfaces of the produced nanocomposites were evaluated using scanning electron microscope (sem). the results show that the surface frac...

Numerical simulation of tracer testing data is conducted based on hydrogeology parameters inferred from pressure interference data. By incorporating both of pressure interferences and tracer testing data, pertinent values of average fracture spacing and rock-matrix permeability can be estimated. Relatively good match of tracer return curves are obtained. It is necessary to assign very small fra...

Aims Prediction of trabecular fracture zone is a wide challenge not yet solved. Some in-vitro studies pointed out the importance of local variation of the framework for the global behavior of the whole trabecular structure [1-4]. Researchers agree that the identification of the weakest link in the trabecular framework can lead to the prediction of the fracture zone, first, and of the failure ev...

We study fracture of notched samples made of quasi-brittle, polyphase materials like rock, concrete or ceramics. The fracture demonstrates the size effect during loading. This means that a full-size sample made of such a material exhibits different fracture behaviour than a laboratory-size sample. The effect is explained by the existence of an extended zone of distributed defects and cracks (pr...

The influence of loading rate (crosshead speed) on the fracture process of bluntly notched samples of pearlitic steel under hydrogen environment is analyzed in this paper. Results indicate that the location of the zone where fracture initiates (fracture process zone) in pearlitic steel samples with a blunt notch directly depends on the loading rate or crosshead speed. For slow testing rates, su...