Laboratory study of cryogenic fracturing of concrete samples

Abstract

While hydraulic fracturing has revolutionized hydrocarbon production from unconventional resources, waterless, or reduced-water technologies, are actively being sought due to concerns arising from its heavy dependence on water and clay swelling in water sensitive formations. Although today it is possible to fracture with liquefied petroleum gas or CO2, there has been very limited research on fracturing using cold liquefied gas. Some simple immersion tests to determine the effectiveness of liquid nitrogen as a fracturing fluid have been conducted with promising results (Grundmann 1998); however, there are no known comprehensive laboratory studies that exhaust the use of liquid nitrogen to determine its effectiveness. This study investigates the feasibility of wellbore fracturing by using pressurized cryogenic fluids to create a thermal gradient generating local tensile stresses on the borehole surface. The thermal tensile stress adds to the stresses incurred by pressurization, which, in many cases, leads to lowered breakdown pressure.