Determination of the stress profile in a deep borehole in a naturally fractured reservoir

In this paper we attempt to determine the stress profile in a naturally fractured reservoir. Having calculated the vertical stress using the conveniently available density data, in dealing with the minimum horizontal stress component, a contribution of tectonic effect has been added to the conventional approach taking the advantages of step rate injection tests which have been performed in the wellbore. This extra term has been taken into account regarding the layered nature of the reservoir and two different producing formations present in the region. Eventually the maximum horizontal stress component has been determined using the frictional faulting theory concepts, and has been validated by taking drilling induced tensile fractures and wellbore breakouts into consideration. In a few depths where both types of wellbore failures were present, consistent results have been reached. A discussion of the results of the maximum horizontal stress determination is provided. (C) 2010 Elsevier Ltd. All rights reserved.