• Controlling the fracture propagation is one of the most challenging engineering problems especially in the oil and gas sector.
• Predicting the fracture orientation becomes more complex when the medium is non-homogeneous and anisotropic while also possessing a non-linear material response.
• One such medium is the porous reservoir which has high leak-off potential whose fracturing behaviour is not clearly understood.
• Thus, a novel testing technique is adopted to simulate the ground conditions in the laboratory and study the instability characteristics of geo-materials.

• Fracture capture simulator (Fig.1) capable of applying true anisotropic boundary stress, injecting fluid at a predefined flow rate and viscosity while imaging fracture propagation is provided.
• Pressure profiles (Fig. 2) and progression of fracture (Fig. 3) are recorded simultaneously during fluid injection process on specimens subjected to different boundary stresses.
• The fracture initiation and evolution are analyzed using image processing, to provide information on fracture area/ orientation, volume change of the specimen and expansion velocities evolution with respect to time during the injection event.

Experiment Setup:

• Fracture capture simulator consists of a top metal cap which houses an injection tube through which the fracturing fluid is injected into the porous geo-material at a predefined flow rate/ pressure.
• To apply two different horizontal stresses on the specimen, a specially designed bladder holder housing four bladders is used.
• The bottom slab is made of transparent Perspex where the specimen is placed, in order to capture the fracture initiation and propagation.
• The imaging setup including the high-speed camera will be placed in-between the reaction columns to image the fracture propagation real-time after application of anisotropic stresses and injecting the fluid.
• A suite of 6 tests (3 cross-isotropic, 3 anisotropic) Fig. 3 have been performed to demonstrate that these experiments are repeatable.