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Title: Hydrodynamics of a vertical hydraulic fracture

We have developed a numerical algorithm, HUBBERT, to simulate the hydrodynamics of a propagating vertical, rectangular fracture in an elastic porous medium. Based on the IFD method, this algorithm assumes fracture geometry to be prescribed. The breakdown and the creation of the incipient fracture is carried out according to the Hubbert-Willis theory. The propagation of the fracture is based on the criterion provided by Griffith, based on energy considerations. The deformation properties of the open fracture are based on simple elasticity solutions. The fracture is assumed to have an elliptical shape to a distance equal to the fracture height, beyond which the shape is assumed to be parallel plate. A consequence of Griffith's criterion is that the fracture must propagate in discrete steps. The parametric studies carried out suggest that for a clear understanding of the hydrodynamics of the hydraulic fracture many hitherto unrecognized parameters must be better understood. Among these parameters one might mention, efficiency, aperture of the newly formed fracture, stiffness of the newly formed fracture, relation between fracture aperture and permeability, and well bore compliance. The results of the studies indicate that the patterns of pressure transients and the magnitudes of fracture length appear to conform tomore » field observations. In particular, the discrete nature of fracture propagation as well as the relevant time scales of interest inferred from the present work seem to be corroborated by seismic monitoring in the field. The results suggest that the estimation of least principal stress can be reliably made either with shut in data or with reinjection data provided that injection rates are very small.« less
Authors:
Publication Date:
OSTI Identifier:
6607801
Report Number(s):
LBL-23175
ON: DE87009278
DOE Contract Number:
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
Research Org:
Lawrence Berkeley Lab., CA (USA)
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; 15 GEOTHERMAL ENERGY; 03 NATURAL GAS; HYDRAULIC FRACTURING; HYDRODYNAMICS; ALGORITHMS; CRACK PROPAGATION; FINITE DIFFERENCE METHOD; GEOLOGIC FRACTURES; COMMINUTION; FLUID MECHANICS; FRACTURING; GEOLOGIC STRUCTURES; ITERATIVE METHODS; MATHEMATICAL LOGIC; MECHANICS; NUMERICAL SOLUTION Geothermal Legacy