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Sayakhov, F. L.; Kovaleva, L. A.; Nasyrov, N. M.

doi:10.1023/a:1014831025835

Cited by 14 publications

(4 citation statements)

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“…Downhole resistive (or ohmic) heaters have also been proposed for heating near the well in heavy-oil reservoirs to reduce the skin effect by near-well viscosity reduction McGee et al 1999a, b), even though this is not efficient for bitumen reservoirs, and its depth of influence is limited. RF EM stimulation has been proposed for heavy-oil-recovery heating in several studies (Abernethy 1976; Islam et al 1991;Sahni et al 2000;Sayakhov et al 2002;Carrizales et al 2008;Davletbaev et al 2011;Kovaleva et al 2011). A number of field tests of bottomhole heating by RF-EM radiation was carried out in Russia, the USA, and Canada (e.g., Spencer 1987Spencer , 1989Kasevich et al 1994).…”

Section: Em-sagd Technologymentioning

confidence: 99%

Evaluation of Induced Thermal Pressurization in Clearwater Shale Caprock in Electromagnetic Steam-Assisted Gravity-Drainage Projects

2013

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Inductive methods, such as electromagnetic steam-assisted gravity drainage (EM-SAGD), have been identified as technically and economically feasible recovery methods for shallow oil-sands reservoirs with overburdens of more than 30 m (Koolman et al. 2008). However, in EM-SAGD projects, the caprock overlying oil-sands reservoirs is also electromagnetically heated along with the bitumen reservoir. Because permeability is low in Alberta thermal-project caprock formations (i.e., the Clearwater shale formation in the Athabasca deposit and the Colorado shale formation in the Cold Lake deposit), the pore pressure resulting from the thermal expansion of pore fluids may not be balanced with the fluid loss caused by flow and the fluid-volume changes resulting from pore dilation. In extreme cases, the water boils, and the pore pressure increases dramatically as a result of the phase change in the water, which causes profound effective-stress reduction. After this condition is established, pore pressure increases can lead to shear failure of the caprock, the creation of microcracks and hydraulic fractures, and subsequent caprock integrity failure. It is typically believed that low-permeability caprocks impede the transmission of pore pressure from the reservoir, making them more resistant to shear failure (Collins 2005(Collins , 2007. In cases of induced thermal pressurization, low-permeability caprocks are not always more resistant. In this study, analytical solutions are obtained for temperature and pore-pressure rises caused by the constant EM heating rate of the caprock. These analytical solutions show that pore-pressure increases from EM heating depend on the permeability and compressibility of the caprock formation. For stiff or low-compressibility media, thermal pressurization can cause fluid pressures to approach hydrostatic pressure, and shear strength to approach zero for low-cohesive-strength units of the caprock (units of the caprock with high silt and sand percentage) and sections of the caprock with pre-existing fractures with no cohesion. IntroductionOf Canada's 179 billion bbl of oil reserves, Alberta's oil sand contains 170.4 billion bbl of those oil reserves (Government of Alberta 2011, 2012, and with the recent increase in demand, tremendous efforts are being made to develop bitumen reservoirs in the coming decades. SAGD is one successful thermal-recovery technique applied to the oil sands of Alberta, Canada. Approximately 80% of the oil sands are recoverable through in-situ production (i.e., they lie at a depth of 75 to 750 m with an average seam thickness of less than 20 m), with only 20% recoverable by mining (i.e., they lie at a depth of 75 m or less with an average seam thickness of 32 m) (Vermeulen and Chute 1983; Government of Alberta 2008).

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Section: Em-sagd Technologymentioning

confidence: 99%

Evaluation of Induced Thermal Pressurization in Clearwater Shale Caprock in Electromagnetic Steam-Assisted Gravity-Drainage Projects

2013

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“…The results of the numerical model have been used to calculate the energy balance factor (К EB ) as given by Sayakhov, Kovaleva and Nasyrov (1998); this method relates the energy equivalent of additional production achieved by a given technique to all the expenditures entailed by applying this technique. In the present case, the calculation has been parameterized by the RF-EM generator power consumption; its efficiency ratio; power line losses from the thermal power plant, where the produced oil is assumed to be used as the heat source, to the generator location; the power line efficiency ratio, and others.…”

Section: Energy Balance Calculationmentioning

confidence: 99%

Recoveries of Heavy Oil and Bitumen Techniques With the Radio Frequency Electromagnetic Irradiation

Kovaleva

Davletbaev²,

Minnigalimov³

2010

All Days

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Production improvement of heavy-oil/bitumen recovery by using Radio-Frequency (RF) Electromagnetic (EM) fields present great practical interest. Most of the material of the oil industry -oil-saturated reservoir, formation fluid, oil, bitumen and their components (resins, asphaltenes, paraffin, oil-water emulsion, high-viscosity and extra-heavy crude oil) in their electromagnetic properties are non-magnetic dielectric materials with low electrical conductivity. If the electromagnetic field impacts these materials, electro-thermo-and hydrodynamic phenomena take place. The RF-EM fields in the form of waves can penetrate deeply enough -from fractions of a meter to several hundred meters -into oil and gas technological working mediaThe paper deals with the impact of EM fields on the heavy-oil/bitumen sand deposit and electro-, thermo-and hydrodynamic processes control for enhanced oil recovery. The present paper discusses the technique of RF-EM heating of an oil-bearing layer combined with solvent injection, aimed at increasing heavy and extra-heavy oil recovery rate. Such combined technology expands the displacement area and allows a deeper heating of the layer. This method increases the technical and economic efficiency of field development by treating a producing well in three stages. At the first stage, the well operates as in injector to inject a solvent with simultaneous RF-EM exposure. At the second stage, the well is suspended to 'stay' without any treatment. Finally, the well is re-commissioned to produce from the layer.The paper presents a mathematical model for this three-stage iterative process, which describes transfer of mass and heat within the 'well/ reservoir/ rock environment' system. A numerical simulation was also employed to study the effect of heavy oil production and the relative energy balance. The model estimates the optimum solvent volume and stage duration; the paper also gives a comparative analysis of calculation results for two cases: the one using the suggested combined technique, the other using constant heating without solvent injection.

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“…For petroleum-based applications, the use of microwaves has been primarily observed in enhanced oil recovery (EOR) techniques. Several studies have been performed to determine the efficiency of electromagnetic heating as a support method for EOR (Kislitsyn and Nigmatulin, 1990;Kovaleva et al, 2004;Sayakhov et al, 2002;Sysoev and Kislitsyn, 2011). In the case of hydrate reservoirs, the decomposition of methane hydrate into gas and water is an endothermic reaction.…”

Section: Introductionmentioning

confidence: 99%

Implementation of a multi-layer radiation propagation model for simulation of microwave heating in hydrate reservoirs

Gupta

Yadav

Das

et al. 2021

HFF

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Purpose This paper aims to present the implementation of a multi-layer radiation propagation model in simulations of multi-phase flow and heat transfer, for a dissociating methane hydrate reservoir subjected to microwave heating. Design/methodology/approach To model the induced heterogeneity due to dissociation of hydrates in the reservoir, a multiple homogeneous layer approach, used in food processes modelling, is suggested. The multi-layer model is incorporated in an in-house, multi-phase, multi-component hydrate dissociation simulator based on the finite volume method. The modified simulator is validated with standard experimental results in the literature and subsequently applied to a hydrate reservoir to study the effect of water content and sand dielectric nature on radiation propagation and hydrate dissociation. Findings The comparison of the multi-layer model with experimental results show a maximum difference in temperature estimation to be less than 2.5 K. For reservoir scale simulations, three homogeneous layers are observed to be sufficient to model the induced heterogeneity. There is a significant contribution of dielectric properties of sediments and water content of the reservoir in microwave radiation attenuation and overall hydrate dissociation. A high saturation reservoir may not always provide high gas recovery by dissociation of hydrates in the case of microwave heating. Originality/value The multi-layer approach to model microwave radiation propagation is introduced and tested for the first time in dissociating hydrate reservoirs. The multi-layer model provides better control over reservoir heterogeneity and interface conditions compared to existing homogeneous models.

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Cited by 14 publications

References 0 publications

Evaluation of Induced Thermal Pressurization in Clearwater Shale Caprock in Electromagnetic Steam-Assisted Gravity-Drainage Projects

Evaluation of Induced Thermal Pressurization in Clearwater Shale Caprock in Electromagnetic Steam-Assisted Gravity-Drainage Projects

Recoveries of Heavy Oil and Bitumen Techniques With the Radio Frequency Electromagnetic Irradiation

Implementation of a multi-layer radiation propagation model for simulation of microwave heating in hydrate reservoirs

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