عنوان مقاله [English]
This paper is concerned with the problem of a plane strain hydraulic fracture transverse to a borehole. Compressibility and near borehole effects are considered to explain the early unstable phase of the fracture growth observed in laboratory experiments, which are potentially applicable to micro fracture experiments conducted in order to determine in-situ stresses. The fracture
grows in an impermeable elastic material. A solution is obtained in terms of fluid net pressure, fracture length and opening. It is shown that the problem depends only on a dimensionless viscosity and an evolution parameter that are related to the compressibility and borehole effect. Instability is identified in the problem after breakdown for an inviscid fluid. The potential for unstable growth depends on the initial flow length, the fluid compressibility, the volume of the fluid and the material elastic modulus.