Evaluation of reservoir deformation induced by water injection in SAGD wells considering formation anisotropy, heterogeneity and thermal effect
Document Type
Article
Publication Date
1-1-2017
Abstract
Heavy oil recovery using steam assisted gravity drainage (SAGD) usually adopts a stimulation process through water injection to the horizontal wellpair in order to expand the pore space in the domain surrounding the dual wells to establish the interwell hydraulic communication, which will offer great benefits for the subsequent development stages. For realistic predictions and evaluations to be made of the efficiency of the stimulation, simulations of the water injection process taking into appropriate account of the rock properties and field conditions are required. This study proposed a comprehensive simulation methodology, which is capable of capturing properly the mechanical responses of the oil sand and the strain-dependent permeability evolution during the injection, as well as of addressing the petrophysical variations along the horizontal wellbores and the temperature effect of the injected water. The simulations were conducted for a real SAGD injection project in an oil field located in Karamay, northwest China, using the mechanical and hydraulic properties calibrated with the laboratory data and the field stress and boundary conditions. The simulations predict the pore pressure distribution and the dilation profile across different sections of the reservoir. In general, the predicted results in terms of bottom hole pressure (BHP) agreed well with the observed. The corresponding reservoir responses disclose that (1) the pay zone basically experiences poroelastic deformations under the field injection conditions and the rock formation parameters considered; (2) the generated pore pressure and development of the dilative zone are dependent on the temperature of the injected water and the position in the reservoir; (3) the degree of stimulation in the interwell domain is explicitly reflected in the temperature responses between the dual wells. These findings not only provide valuable information/guidance for the field production engineers to evaluate and improve the stimulation work, but also the approach proposed may be used to analyze the water injection problems involving other types of unconsolidated sandstone reservoirs.
Publication Source (Journal or Book title)
Journal of Petroleum Science and Engineering
First Page
767
Last Page
779
Recommended Citation
Lin, B., Chen, S., & Jin, Y. (2017). Evaluation of reservoir deformation induced by water injection in SAGD wells considering formation anisotropy, heterogeneity and thermal effect. Journal of Petroleum Science and Engineering, 157, 767-779. https://doi.org/10.1016/j.petrol.2017.07.067