Date of Award
Doctor of Philosophy
An explicitly coupled finite element framework is developed to address the in-situ pyrolysis of oil shale by radio frequency heating. This framework is constructed by coupling equations describing thermal, phase field, mechanical, and electromagnetic (TPME) phenomena to describe this enhanced oil recovery method. This work focuses on the development of a numerical simulation tool using two-dimensional finite element analysis to model heat generation by electromagnetic energy and the conversion of solid kerogen into liquid oil for subsequent production. The conversion of solid to liquid matter in the subsurface induces deformation of the subsurface formation leading to quantifiable uplift and subsidence. In the absence of readily available numerical models of field data for calibration, a verification process is undertaken which leverages the Method of Manufactured Solutions. Upon verification of the numerical framework uncertainty quantification is performed in order to evaluate epistemic uncertainty associated with selected physical characteristics of oil shale. Lastly, the TPME framework is used to model a variety of scenarios describing oil shale of differing kerogen content, and situated in disparate geological and operational scenarios. Results show the conversion of solid kerogen to liquid oil by way of phase field interface arrival time for a target kerogen-rich formation, as well as the determination of vertical mechanical displacement of the formation due to post-conversion stress dissipation. The end result is a distribution of operating scenarios which can be taken into consideration in the development of the resource using radio frequency heating as an enhanced oil recovery method.
Travis St. George Ramsay
Ramsay, Travis St. George, "Numerical modeling of oil shale in-situ pyrolysis by radio frequency heating using a thermal – phase field – mechanical – electromagnetic (TPME) two-dimensional finite element method framework" (2020). Graduate Theses and Dissertations. 18385.