Geomechanical Considerations when Planning SAGD Wells, a Case Study from Cuba

Abstract

This article is the first part of the geomechanical calculations performed in order to optimize the drilling and production operations of the first horizontal wells with target formation M in the Boca de Jaruco field, Republic of Cuba. Here, the analyzed data included regional geology, tectonics and stratigraphy, different types of well logging, the pressure curves while steam operations, core samples and drilling history. The outcome of this part of the work is the assessment of the current stress regime, stress directions and the stability windows for the planned wells. Moreover, the program of additional studies and logs acquisition was elaborated, as at this stage there is not enough data to confidently quantify the stress state, the core samples are not yet tested for rock's deformation and strength properties, and it is hardly possible to find carbonate bitumen deposits under development anywhere in the world which are analogous to the Boca de Jaruco field (with the sole exception of Grosmont in Northern Alberta, Canada). After the wells are drilled (presumably by the end of 2019) and the required information is collected (such as mechanical core testing under elevated temperatures, image logs in the deviated boreholes, etc.), the second part of the work is to be performed, which would include the analysis of the drilling results and the assessment of the cap rock behavior, pore pressure and porosity-permeability changes due to steam injection.