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 three-dimensional fully-coupled poroelastic displacement discontinuity method is developed and used to analyze the temporal variation of opening and slip of a natural fracture in a reservoir in response to the sudden application of fluid pressure in the fracture surfaces. Numerical results show that a hydraulic fracture opens in an increasing manner with time as the rock moves towards a drain...

Stress-intensity factors (SIFs) are the most important parameters in fracture mechanics analysis of structures. These parameters are evaluated for a stationary crack in functionally graded plates of arbitrary geometry using a novel Galerkin based mesh-free method. The method involves an element-free Galerkin method (EFGM), where the material properties are smooth functions of spatial coordinate...

Brittle materials such as rock and ceramic usually exhibit apparent increases of strength and toughness when subjected to dynamic loading. The reasons for this phenomenon are not yet well understood, although a number of hypotheses have been proposed. Based on dynamic fracture mechanics, the present work offers an alternate insight into the dynamic behaviors of brittle materials. Firstly, a sin...

Some fundamental mechanisms associated with cooling/heating of the rock in the context of drilling and reservoir stimulation in enhanced geothermal systems are described. The role of temperature and pore pressure in wellbore failure and fracture width is considered using analytical and boundary element models. Results indicate that cooling induces a pore pressure drop inside the formation that ...

Data on discontinuities are always necessary for design, characterization and analysis of rock structures. The time honored method of manual measurements with Brunton compass is both time consuming and often inconvenient given issues such as restricted access to measurement areas, introduction of erroneous data due to sampling difficulties and human bias, considerable safety risks since measure...

To obtain the effect of fracture failure mechanics characteristics and behavior brittle rock masses on compound factors fissure openings inclination, uniaxial loading tests were performed single-fissured rock-mass specimens with different using a test machine. The results show that increase in openings, fissured peak strength variation inclination angle changes from first decreasing then increa...

High resolution measurements of fracture aperture of granite and sandstone rocks were performed using CAT scanner. The aperture distribution was statistically characterized for future experimental and numerical studies on single and multiphase flow and transport. The fracture aperture can be measured in-situ and nondestructively with CAT-scanning. The minimum pixel size is 0.27 x 0.27 mm, but f...