Uncertainty Quantification of an Explicitly Coupled Multiphysics Simulation of In-Situ Pyrolysis by Radio Frequency Heating in Oil Shale

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1443-1461
Author(s):  
Travis Ramsay
Keyword(s):  
Radio Frequency ◽  
Uncertainty Quantification ◽  
Oil Shale ◽  
Oil And Gas ◽  
Polynomial Chaos ◽  
Epistemic Uncertainty ◽  
Rf Heating ◽  
Commercial Development ◽  
Mc Simulation

Summary In-situ pyrolysis provides an enhanced oil recovery (EOR) technique for exploiting oil and gas from oil shale by converting in-place solid kerogen into liquid oil and gas. Radio-frequency (RF) heating of the in-place oil shale has previously been proposed as a method by which the electromagnetic energy gets converted to thermal energy, thereby heating in-situ kerogen so that it converts to oil and gas. In order to numerically model the RF heating of the in-situ oil shale, a novel explicitly coupled thermal, phase field, mechanical, and electromagnetic (TPME) framework is devised using the finite element method in a 2D domain. Contemporaneous efforts in the commercial development of oil shale by in-situ pyrolysis have largely focused on pilot methodologies intended to validate specific corporate or esoteric EOR strategies. This work focuses on addressing efficient epistemic uncertainty quantification (UQ) of select thermal, oil shale distribution, electromagnetic, and mechanical characteristics of oil shale in the RF heating process, comparing a spectral methodology to a Monte Carlo (MC) simulation for validation. Attempts were made to parameterize the stochastic simulation models using the characteristic properties of Green River oil shale. The geologic environment being investigated is devised as a kerogen-poor under- and overburden separated by a layer of heterogeneous yet kerogen-rich oil shale in a target formation. The objective of this work is the quantification of plausible oil shale conversion using TPME simulation under parametric uncertainty; this, while considering a referenced conversion timeline of 1.0 × 107 seconds. Nonintrusive polynomial chaos (NIPC) and MC simulation were used to evaluate complex stochastically driven TPME simulations of RF heating. The least angle regression (LAR) method was specifically used to determine a sparse set of polynomial chaos coefficients leading to the determination of summary statistics that describe the TPME results. Given the existing broad use of MC simulation methods for UQ in the oil and gas industry, the combined LAR and NIPC is suggested to provide a distinguishable performance improvement to UQ compared to MC methods.

scholarly journals Cyclic Subcritical Water Injection into Bazhenov Oil Shale: Geochemical and Petrophysical Properties Evolution Due to Hydrothermal Exposure

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4570
Author(s):  
Aman Turakhanov ◽  
Albina Tsyshkova ◽  
Elena Mukhina ◽  
Evgeny Popov ◽  
Darya Kalacheva ◽  
...  
Keyword(s):  
Energy Demand ◽  
Oil Shale ◽  
Oil And Gas ◽  
Subcritical Water ◽  
Pore Space ◽  
Water Injection ◽  
Microstructural Properties ◽  
Gas Generation ◽  
Geochemical Parameters

In situ shale or kerogen oil production is a promising approach to developing vast oil shale resources and increasing world energy demand. In this study, cyclic subcritical water injection in oil shale was investigated in laboratory conditions as a method for in situ oil shale retorting. Fifteen non-extracted oil shale samples from Bazhenov Formation in Russia (98 °C and 23.5 MPa reservoir conditions) were hydrothermally treated at 350 °C and in a 25 MPa semi-open system during 50 h in the cyclic regime. The influence of the artificial maturation on geochemical parameters, elastic and microstructural properties was studied. Rock-Eval pyrolysis of non-extracted and extracted oil shale samples before and after hydrothermal exposure and SARA analysis were employed to analyze bitumen and kerogen transformation to mobile hydrocarbons and immobile char. X-ray computed microtomography (XMT) was performed to characterize the microstructural properties of pore space. The results demonstrated significant porosity, specific pore surface area increase, and the appearance of microfractures in organic-rich layers. Acoustic measurements were carried out to estimate the alteration of elastic properties due to hydrothermal treatment. Both Young’s modulus and Poisson’s ratio decreased due to kerogen transformation to heavy oil and bitumen, which remain trapped before further oil and gas generation, and expulsion occurs. Ultimately, a developed kinetic model was applied to match kerogen and bitumen transformation with liquid and gas hydrocarbons production. The nonlinear least-squares optimization problem was solved during the integration of the system of differential equations to match produced hydrocarbons with pyrolysis derived kerogen and bitumen decomposition.

scholarly journals Thermodynamic mechanism evaluate the feasibility of oil shale pyrolysis by topochemical heat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuai Zhao ◽  
Xiaoshu Lü ◽  
Youhong Sun ◽  
Jiandong Huang
Keyword(s):  
Transition State ◽  
Oil Shale ◽  
Oil And Gas ◽  
Early Stage ◽  
Oil Production ◽  
Pilot Project ◽  
Main Stage ◽  
Oil Shale Pyrolysis ◽  
Heat Method

AbstractTopochemical heat in-situ pyrolysis of oil shale is achieved by injecting high temperature nitrogen to promote oil shale pyrolysis and release heat, and then injecting air to trigger oil shale combustion in the early stage of oil shale pyrolysis, and then by injecting normal temperature air continuously to promote local oxidation of oil shale in the later stage. In order to verify the oil and gas recovery by topochemical heat method, Jilin University has chosen Fuyu City, Jilin Province, to carry out pilot project of oil shale in-situ pyrolysis by topochemical heat method. Besides, in order to infer the spontaneity, feasibility and difficulty of continuous pyrolysis of oil shale based on topochemical heat, this paper, the mechanism of solid-state pyrolysis and the thermodynamic analysis of transition state of oil shale in Fuyu area are discussed. Because the second stage of oil shale pyrolysis is the main stage of oil production. Therefore, the characteristics of Gibbs free energy, free enthalpy and free entropy of transition state in the main oil production stage of oil shale pyrolysis are obtained by calculation. The results show that in situ pyrolysis of oil shale topochemical heat can be carried out spontaneously and continuously, and the release characteristics of volatiles during pyrolysis of oil shale are described.

Application Prospects in China of Oil Shale In Situ Mining Method and an Improved Method

2014 ◽  
Vol 535 ◽  
pp. 602-605 ◽  
Author(s):  
Gui Jie Zhao ◽  
Chen Chen ◽  
Fang Qian
Keyword(s):  
Alternative Energy ◽  
Oil Shale ◽  
Oil And Gas ◽  
Outlet Channel ◽  
Heat Efficiency ◽  
Initial Stage ◽  
New Energy ◽  
Development And Utilization ◽  
Mining Methods

Oil shale resources is a new energy has a huge potential for development, as the complement and alternative energy of the oil and gas, more and more people pay attention to it. China's oil shale resources are widely distributed and reserves are huge, but current mining methods are still primitive, mainly to direct exploitation, exploitation efficiency is low and ecological damage is serious, it will be replaced by in-situ mining methods in the future. This paper summarizes the research of oil shale in situ mining, aims at the problems of that the conduction of heat efficiency is low and the outlet channel is less which exist in the in-situ mining at the present, and put forward the concept of in-situ broken that is using some methods to make the oil shale change from huge to small block in the initial stage of the in-situmining, further in-situ heating, mining of oil shale，and put forward the method of in-situ noncontact wind breaking oil shale, this method using the crushing wind to break the oil shale, having high feasibility. This paper did in-depth research on the in-situ mining, and it can provide a reference for the development and utilization of oil shale resources.

Radio Frequency Heating Simulation Using A Reservoir Simulator Coupled with Electromagnetic Solver for Soil Remediation

2021 ◽  
Author(s):  
Xiaoyue Guan ◽  
Gary Li ◽  
Hanming Wang ◽  
Shubo Shang ◽  
Timothy Tokar ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Simulation Model ◽  
Soil Remediation ◽  
Field Test ◽  
Test Data ◽  
History Matching ◽  
Heating Process ◽  
Rf Heating ◽  
Reservoir Simulator

Abstract Radio frequency (RF) heating is recognized as a technique having the potential to thermally enhance remediation of hydrocarbon-impacted soil. RF heating delivers electromagnetic (EM) power to a targeted body of soil, resulting in an increased soil temperature that enhances the in-situ remediation processes such as biodegradation. Antennas are placed either on the ground or installed in the soil near the ground surface. The antennas operate in the hundreds of kHz to MHz range. To model the RF heating process, we successfully coupled a reservoir simulator with a 3-dimensional (3D) EM solver to evaluate the ability of RF technology to heat soil in situ. The coupled reservoir/EM simulator solves the EM fields and associated heating for a heterogeneous reservoir or soil volume in the presence of multiple antennas. The coupling was accomplished through a flexible interface in the reservoir simulator that allows the runtime loading of third-party software libraries with additional physics. This coupled workflow had been previously used for studying RF heating for heavy oil recovery (Li 2019). An RF heating simulation case study was performed in support of a soil remediation field test designed to demonstrate the ability to heat soils using EM energy. The study included field test data analysis, simulation model building, and history matching the model to test data. Results indicate, on average, the soil was heated ∼2-3°C above the initial formation temperature after approximately two days (52 hours) of RF heating. We found that the RF heating was local, and our simulation model, after tuning input parameters, was able to predict a temperature profile consistent with the field test observations. With properly designed RF heating field pilots and tuning of EM and reservoir parameters in simulation models, the coupled reservoir/EM simulator is a powerful tool for the calibration, evaluation, and optimization of RF heating operations.

Numerical Simulation of the In-Situ Upgrading of Oil Shale

SPE Journal ◽  
2010 ◽  
Vol 15 (02) ◽  
pp. 368-381 ◽  
Author(s):  
Y.. Fan ◽  
L.J.. J. Durlofsky ◽  
H.A.. A. Tchelepi
Keyword(s):  
Chemical Reaction ◽  
Oil Shale ◽  
Oil And Gas ◽  
Energy Resource ◽  
General Purpose ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Design And Optimization ◽  
Compositional Flow

Summary Oil shale is a highly abundant energy resource, though commercial production has yet to be realized. Thermal in-situ upgrading processes for producing hydrocarbons from oil shale have gained attention recently, however, in part because of promising results reported by Shell using its in-situ conversion process (Crawford et al. 2008). This and similar processes entail heating the oil shale to approximately 700°F (371°C), where the kerogen in the shale decomposes through a series of chemical reactions into liquid and gas products. In this paper, we present a detailed numerical formulation of the in-situ upgrading process. Our model, which can be characterized as a thermal/compositional, chemical reaction, and flow formulation, is implemented into Stanford's General Purpose Research Simulator (GPRS). The formulation includes strongly temperature-dependent kinetic reactions, fully compositional flow and transport, and a model for the introduction of heat into the formation through downhole heaters. We present detailed simulation results for representative systems. The model and heating patterns are based on information in Shell publications; chemical-reaction and thermodynamic data are from previously reported pyrolysis experiments. After a relatively modest degree of parameter adjustment (with parameters restricted to physically realistic ranges), our results for oil and gas production are in reasonable agreement with available field data. We also investigate various sensitivities and show how production is affected by heater temperature and location. The ability to model these effects will be essential for the eventual design and optimization of in-situ upgrading operations.

Radio‐frequency geotomography for remotely probing the interiors of operating mini‐ and commercial‐sized oil‐shale retorts

Geophysics ◽  
1984 ◽  
Vol 49 (8) ◽  
pp. 1288-1300 ◽  
Author(s):  
Stephen F. Somerstein ◽  
Mike Berg ◽  
David Chang ◽  
Hwang Chung ◽  
Hal Johnson ◽  
...  
Keyword(s):  
High Temperature ◽  
Radio Frequency ◽  
Oil Shale ◽  
Vertical Plane ◽  
Skin Depth ◽  
Image Resolution ◽  
High Signal ◽  
Signal Attenuation ◽  
Attenuation Coefficients

Cross‐borehole, radio‐frequency geotomographs were made across two different‐sized, operating, experimental, underground, in‐situ, oil‐shale retorts. The tomographs taken of the smaller retort were of a plane 16.7 m wide by 18.0 m high bisecting the retort. The measurements were taken at a frequency of 25 MHz and showed excellent correlation of high signal attenuation with the high‐temperature zones. Measured attenuation coefficients (inverse skin depth) at 25 MHz ranged from [Formula: see text] across the cool, unrubbled, sill‐pillar, and between [Formula: see text] for the high‐temperature 370–700° C zone. Image resolution was approximately 1 m. The signal attenuation across the lower retort region was also found to correlate well with the movement and concentration of condensed water. The conventional algebraic deconvolution method (ART) was modified for limited perspective and finite beam width, and gave results which were in good agreement with thermocouple data. The measurements made on the larger retort were taken over a period of 33 days of retort burn and mapped the attenuation coefficients in a vertical plane 90 m wide by 48 m high at a frequency of 1.5 MHz. At this frequency, attenuation coefficients in the cool, dry retort regions were between 0.12 and [Formula: see text], while regions containing a high moisture content had coefficients of from 0.15 to [Formula: see text]. In the regions encompassing the retorting and combustion zones, attenuation coefficients were between 0.15 and [Formula: see text]. Some additional effects on the attenuation measurements were observed due to nearby thermocouple piping. The movement of the contours of attenuation coefficient with time followed temperature changes, though the paucity of thermocouples in the tomographic plane only allowed a marginal correlation to be made. Overall results suggest that radio‐frequency geotomography can be a useful tool for mapping in‐situ moisture concentrations and temperature fronts in an operating in‐situ oil‐shale retort.

scholarly journals Release characteristics of Pb and BETX from in situ oil shale transformation on groundwater environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Han Wang ◽  
Wenjing Zhang ◽  
Shuwei Qiu ◽  
Xiujuan Liang
Keyword(s):  
Alternative Energy ◽  
Oil Shale ◽  
Oil And Gas ◽  
Ex Situ ◽  
Rock Interaction ◽  
Groundwater Environment ◽  
Benzene Series ◽  
Over Time ◽  
Water Rock Interaction

AbstractOil shale has received attention as an alternative energy source to petroleum because of its abundant reserves. Exploitation of oil shale can be divided into two types: ex situ and in situ exploitation. In situ transformation has been favoured because of its various advantages. Heating of oil shale leads to the production of oil and gas. To explore the influence of solid residue after pyrolysis of oil shale on the groundwater environment, we performed ultrapure water–rock interaction experiments. The results showed that Pb tended to accumulate in solid residues during pyrolysis. Additionally, the Pb concentration goes up in the immersion solution over time and as the pyrolysis temperature increased. In contrast, when we measured the soaking data of benzene series, the concentrations of benzene and toluene produced at temperatures over 350 ℃ were highest in the four oil shale pyrolysis samples after pyrolysis. The water–rock interaction experiment for 30 days led to benzene and toluene concentrations that were 104 and 1070-fold over the limit of China’s standards for groundwater quality. Over time, the content of benzene series was attenuated via biological actions. The results show that in situ oil shale mining can lead to continuous pollution in the groundwater environment.

Uncertainty Quantification of Allen-Cahn Phase Field Parameters in Multiphysics Simulation of Oil Shale Radio Frequency Heating

2021 ◽  
Author(s):  
Travis Ramsay
Keyword(s):  
Finite Element ◽  
Phase Field ◽  
Oil Shale ◽  
Polynomial Chaos ◽  
Rock Type ◽  
Reaction Diffusion ◽  
Chaos Expansion ◽  
Summary Statistics ◽  
Rf Heating ◽  
Simulation Results

Abstract Radio frequency (RF) heating represents a dielectric heating technique for converting kerogen-rich oil shale into liquid oil through in-situ pyrolysis. This process can be modeled using a multiphysics finite element based coupled thermal, phase field, mechanical and electromagnetic (TPME) numerical framework. This work focuses on the combination of a two-dimensional (2D) TPME multiphysics simulation with uncertainty quantification (UQ) that incorporates the Allen-Cahn phase field parameters, specifically those which describe the associated reaction-diffusion process as electromagnetic energy being converted to thermal energy in the RF heating process. The breadth of UQ performed in this study includes not only the Allen-Cahn parameters but also selected thermal, statistical rock-type distribution in the geological model, as well as electromagnetic parameters of the applied quasi-static Maxwell equation. A Non-Intrusive Polynomial Chaos (NIPC) is used for: considering the affect of Allen-Cahn phase field parameters on the evaluation of plausible conversion timelines of TPME simulation and the evaluation of summary statistics to predict the order of Polynomial Chaos Expansion (PCE) that is representative of full kerogen-rich zonal conversion response in a geologically descriptive finite element model. A sparse representation of polynomial chaos coefficients is highlighted in the process of computing summary statistics for the complex stochastically-driven TPME simulation results. Additionally, Monte Carlo (MC) simulations were performed in order to validate the results of the sparse NIPC representation. This is done considering MC is a widely recognized stochastic simulation process. Additionally, NIPC was used to illustrate the potential performance improvement that are possible, with a sparse polynomial chaos expansion enhanced by the incorporation of Least Angle Regression (LAR), as compared to MC simulation. Although the parametic uncertainty of the reaction-diffusion parameters of the Allen-Cahn was comprehensive, they did not accelerate the conversion timelines associated with the full zonal conversion of the kerogen-rich rock type in the statistical simulation results. By executing the stochastic simulations for a greater length of time the extent of full zonal conversion is examined in the RF modeling.

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