AN EXPERIMENTAL INVESTIGATION INTO HYDRAULIC FRACTURE PROPAGATION .2. SINGLE WELL TESTS

This paper presents the experimental results of single well hydraulic fracture tests. The tests were conducted in dry gypstone blocks of 305 x 305 x 305 mm. True triaxial stresses were applied to the specimens. Leak-off was incorporated. The deformation of the specimens during injection was monitored to provide further data to characterize the fracture. The fracture and the oil penetration area were observed after testing. The influences of the least principal stress and the injection rate on fracture propagation were studied. The experiments produced considerable data on build-up of bottomhole pressure before breakdown, breakdown pressure under various states of stress and injection rates, behavior of fracture propagation post breakdown, and leak -off behavior. The monitoring of fracture propagation post breakdown and observation of leak -off provided data for a leak -off dominated material for use in numerical models.