Stress Determination by Hydraulic Fracturing in Subsurface Waste Injection

By the utilization of commercially available and specially designed equipment, hydraulic fracturing experiments were conducted on a regional scale in the Piceance Basin of northwest Colorado. These tests confirmed that vertical fractures may be hydraulically induced at well-face injection pressure of about two thirds of the total overburden load. Further, the fractures will continue to propagate vertically as long as injection pressure exceeds the combined value of least principal horizontal stress and tensile strength which may lead to contamination of potable water aquifer and may trigger earthquakes.