This paper presents a novel technique for assessment of fracture and injection domain geometry from fall off tests. Using type curve analysis techniques established in part for long term water injection, algorithms were developed for assessment of geomechanical and fracture properties of injectors. These properties include the stress contrast between the injection and containment layers, the rate of fracture shrinkage (height and/or length) during fall off, the extent of the inner relative permeability domain and outer domain, and others.
A software tool was developed to incorporate these algorithms. The tool was used to analyze fall-off test results obtained from a large-scale slurry injection operation used for disposal of drilling wastes in Alaska’s North Slope. The software tool’s predicted fracture height showed very good agreement to the height interpreted from temperature logs conducted by the operator in the well.