Signature of seismic wave attenuation during fracture network formation

Ultrasonic velocity and attenuation anisotropy of shales, Whitby, United Kingdom

We have conducted ultrasonic experiments, between 0.3 and 1 MHz, to measure velocity and attenuation (Q?1) anisotropy of P- and S-waves in dry Whitby Mudstone samples as a function of stress. We found the degree of anisotropy to be as large as 70% for velocity and attenuation. The sensitivity of P-wave anisotropy change with applied stress is...

Investigation on Mechanical Behaviour of Coal and Overburden Rock for UCG

In recent years, the coupled UCG-CCS process has been considered as another potential CCS option, which can offer integrated energy recovery from coal and storage of CO2. However, existing potential problems may counteract its potential benefits. To develop a generic UCG-CCS site characterisation workflow, different aspects of this complex...

Study of shale wettability for CO2 storage

For a water-saturated cap-rock, which consists of a low-permeability porous material, the wettability of the reservoir rock-connate water- CO2 system and the interfacial tension (IFT) between CO2 and connate water are the significant parameters for the evaluation of the capillary sealing. Also, the amount of capillary-trapped CO2 depends on the...

Variations in petrophysical properties of shales along a stratigraphic section in the Whitby mudstone (UK)

Fracture network growth for prediction of fracture characteristics and connectivity in tight reservoir rocks

Fracturing experiments on very low-porosity dolomite rocks shows a difference in growth of fracture networks by stress-driven fracturing and fluid-driven fracturing. Stress-driven fracture growth, in the absence of fluid pressure, initially forms fractures randomly throughout the rocks followed by growth and coalescence of fractures to form a...