Journal of Petroleum & Environmental Biotechnology

Role of discontinuities on hydro-mechanical properties of shale caprock overlying steam assisted gravity drainage

3^rd International Conference and Expo on Oil and Gas

July 13-14, 2017 Berlin, Germany

Abeer Heikal and Rick Chalaturnyk

University of Alberta, Canada

Posters & Accepted Abstracts: J Pet Environ Biotechnol

Abstract:

Steam assisted gravity drainage (SAGD) is used in Alberta to stimulate immobile bitumen to produce it from oil sands. The caprock is ultimate seal of bitumen that can effectively withstand stresses and strains induced from SAGD processes throughout life of reservoir. The caprock here is soft and heterogeneous. It is comprised of mudstone, shale and silt facies from clear water formation. Assessing caprock integrity is a challenging operational problem in any SAGD project. With increased heating and as steam chamber grows, caprock heaves. In past, there have been multiple documented steam and bitumen leaks. The objectives of this research include demonstrating importance of capturing shale caprock anisotropy via considering effect of natural discontinuities in the accurate determination of an equivalent continuum. The research aims to highlight fundamental role of discontinuities on hydro-mechanical properties of fractured caprock. It focuses on illustrating how discontinuities affect caprock deformability and its seal/flow characteristics. Research methodology includes fundamental characterization of clear water shale geological framework using in situ data captured by Light Detection and Ranging (LiDaR) technique. Numerical simulations have been carried out using 3D Distinct Element Code (3DEC). The index parameters needed were determined from laboratory testing. Preliminary results of an analysis comparing continuum versus discontinuum modeling illustrated the crucial role the discontinuities play in precisely determining the magnitude of uplift of caprock above SAGD. Neglecting discontinuities can result in an underestimation of heave value and overestimation of flow-resistance characteristics of caprock. New practical addition of this research is inherent in generating a fundamental integrated workflow that can be conveniently followed to build a geomechanical model from geological in situ data. The novel contribution of this research to the oil and gas industry includes studying a 3D DEM of a deterministic DFN of caprock.

Biography :

Email: heikal@ualberta.ca