scholarly journals Permeability Evolution of Pyrolytically-Fractured Oil Shale under In Situ Conditions

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3033 ◽  
Author(s):  
Fuke Dong ◽  
Zijun Feng ◽  
Dong Yang ◽  
Yangsheng Zhao ◽  
Derek Elsworth
Keyword(s):  
Oil Shale ◽  
Oil And Gas ◽  
Gas Production ◽  
Peak Temperature ◽  
Threshold Temperature ◽  
Rapid Rise ◽  
Permeability Evolution ◽  
Triaxial Stresses ◽  
In Situ Conditions

In-situ injection of steam for heating of the subsurface is an efficient method for the recovery of oil and gas from oil shale where permeability typically evolves with temperature. We report measurements on Jimusar oil shales (Xinjiang, China) at stepped temperatures to 600 °C and under recreated in situ triaxial stresses (15 MPa) and recover permeability evolution with temperature and stress. Initial very low permeability evolves with the temperature above an initial threshold temperature at high rate before reaching a plateau in permeability above a peak temperature. The threshold temperature triggering the initial rapid rise in permeability is a function of triaxial stresses. For Jimusar oil shale, this threshold temperature ranges from 200 °C to 250 °C for burial depths of 500 m and from 350 °C to 400 °C for burial depths of 1000 m. This rapid rise in permeability correlates with the vigor of pyrolysis and directly scales with the production rate of pyrolysis-derived gas production. The permeability increases with temperature to a plateau in peak permeability that occurs at a peak-permeability temperature. This peak temperature is insensitive to stress and is in the range 450 °C to 500 °C for all Jimusar samples. Pyrolysis plays an important role in the stage of rapid permeability evolution with this effect stopping once pyrolysis is essentially complete. At these ultimate high temperatures, permeability exhibits little reduction due to stress and remains elevated due to the vigor of the pyrolysis. These results effectively demonstrate that oil shale may be transformed by pyrolysis from a tight porous medium into highly permeable medium and that oil and gas may be readily recovered from it.

scholarly journals Permeability evolution of pyrolytically-fractured oil shale under in situ conditions

2018 ◽  
Author(s):  
Fuke Dong ◽  
Zijun Feng ◽  
Dong Yang ◽  
Yangsheng Zhao ◽  
Dereck Elsworth
Keyword(s):  
Oil Shale ◽  
Oil And Gas ◽  
Peak Temperature ◽  
Threshold Temperature ◽  
Stress Effect ◽  
Permeability Evolution ◽  
Triaxial Stresses ◽  
In Situ Conditions ◽  
Oil Shales

In-situ injection of steam for heating of the subsurface is an efficient method for the recovery of oil and gas from oil shale where permeability typically evolves with temperature. We reported measurements on Jimusar oil shales(Xinjiang, China) at different temperatures to 600℃ and under recreated in situ triaxial stresses to obtain permeability evolution with temperature and stress. Permeability of tight oil shales evolves with temperature to a threshold temperature and peak temperature. The threshold temperature was subjected to triaxial stresses. For Jimusar oil shale, the threshold temperature ranges from 200℃ to 250℃ at ground stress of buried depth of 500m and from 350℃ to 400℃ at buried depth of 1000m. The peak temperature was almost not subjected to triaxial stress and the range is from 450℃ to 500℃ for all Jimusar samples. Pyrolysis plays an important role in permeability evolution and fundamentally changes permeability tendency and magnitude. At high temperature permeability exhibits a little reduction due to stress effect but still remains a high level due to pyrolysis. The above results show that oil shale mass can change from tight porous media into highly permeable media and oil & gas can easily flow through oil shale stratum.

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.

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.

Mechanics of Geological Materials

1985 ◽  
Vol 38 (10) ◽  
pp. 1256-1260 ◽  
Author(s):  
M. M. Carroll
Keyword(s):  
Solid Mechanics ◽  
Oil And Gas ◽  
Rock Fracture ◽  
Energy Resource ◽  
Earthquake Hazard ◽  
Soil Liquefaction ◽  
Failure Behavior ◽  
Geological Materials ◽  
In Situ Conditions

Needed advances in various areas of energy resource recovery, underground construction, earthquake hazard reduction, and conventional and nuclear defense depend critically on the development of improved theories for mechanical and thermal behavior of geological materials. The areas include oil and gas (including off-shore and Arctic production), mining and in situ recovery, geothermal production, nuclear waste isolation, under-ocean tunneling, underground storage, nuclear test containment, and effects of surface explosions. The needed developments, some of which are detailed in earlier National Academy of Science reports, include constitutive theories for inelastic deformation, failure, and post-failure behavior, influence of microstructure and macrostructure, rock fracture (direct breakage, hydraulic fracture explosive fracture), frictional sliding, soil liquefaction, mechanics of ice, determination of in situ conditions, flow through porous media, and thermal effects. Advances in mechanics of geological materials will require adaptation of some established techniques in rheology, metal plasticity, composite materials, mixtures, etc., and also the development of some entirely new ideas and methods. The complicated nature of rocks and soils, the wide ranges of stress, temperature, strain rate, etc., the interactions encountered in geotechnical processes, and the vastly different dimensions and time scales involved, lead to a host of challenging problems in solid mechanics.

LEGAL FRAMEWORK AND LIABILITY OF LEAVING OIL AND GAS FACILITIES IN-SITU OR DEEP SEA DISPOSAL ON AUSTRALIA’S CONTINENTAL SHELF

2004 ◽  
Vol 44 (1) ◽  
pp. 809
Author(s):  
I.V. Stejskal
Keyword(s):  
Continental Shelf ◽  
Oil And Gas ◽  
Petroleum Industry ◽  
Legal Framework ◽  
Gas Production ◽  
Economic Life ◽  
Oil And Gas Production ◽  
Operational Life ◽  
Accepted Practice

Australia’s offshore petroleum industry is beginning to mature and many of its offshore oil and gas production facilities are reaching the end of their operational life. These facilities consist of an array of infrastructure including wells, wellheads, platforms and monopods of various construction, pipeline and flowlines, and anchors and risers. Many of these facilities will need to be decommissioned at the end of their operational and economic life in a safe and environmentally responsible manner.The Australian government has the jurisdiction to direct a company to remove all facilities associated with offshore production projects located on Australia’s continental shelf, but there is room for discretion for other decommissioning options. The manner in which facilities are decommissioned must be assessed on a case-by-case basis, taking into account factors such as technical feasibility, commercial risk, safety and social impacts, costs and environmental effects.Two decommissioning options appropriate in some instances are to leave selected facilities in-situ or dispose of a facility to some other location on the continental shelf, preferably in deep water. Residual liability refers to the responsibility and liability associated with leaving facilities on the seabed. If a facility is allowed to remain on the seabed, questions related to residual liability arise:who is responsible for any facility left on the seabed; andwho is liable to pay for compensation in the event that this facility is allowed to remain in place on the seabed and injury or damage is caused to a third person or property?There is no universally accepted practice in relation to residual liability in relation to decommissioning. In some countries, the State assumes responsibility; in other countries the company remains responsible in perpetuity. This issue still needs to be clarified in Australia.

scholarly journals RISK ANALYSIS OF THE PILLAR STRENGTH IN THE ESTONIA MINE

2015 ◽  
Vol 1 ◽  
pp. 19
Author(s):  
Juri-Rivaldo Pastarus ◽  
Sergei Sabanov ◽  
Jekaterina Shestakova ◽  
Oleg Nikitin
Keyword(s):  
Experimental Data ◽  
Risk Analysis ◽  
Moisture Content ◽  
Bearing Capacity ◽  
Oil Shale ◽  
Volume Density ◽  
Analysis Method ◽  
Strength Parameters ◽  
In Situ Conditions

This paper deals with the risk analysis and assessment of the pillars strength problems in the Estonia oil shale mine. Aim of this investigation was to determine the strength parameters and predict the bearing capacity of the pillars in Estonia mine, mining block No. 3107 Methods were based on theoretical investigation and experimental data of in-situ conditions. It is given the geological description of the mining block and determined the strength parameters, moisture content and volume density of the oil shale and limestone layers. Analysis showed that the used risk analysis method is applicable for Estonian oil shale mines. The results of the risk analysis are of particular interest for practical purposes.

In-Situ Sensing of Underwater Gas Releases

2021 ◽  
Author(s):  
Chetan Laddha ◽  
Lorna Ortiz-Soto ◽  
Leslie Baksmaty ◽  
Juan Dominguez-Olivo
Keyword(s):  
Oil And Gas ◽  
Building Blocks ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Technological Gap ◽  
Sensing Technology ◽  
In Situ Sensing ◽  
Reliable Solution

Abstract The O&G industry has been producing hydrocarbons from subsea reservoirs for several decades. However, there is a technological gap in the ability to reliably detect and quantify dissolved gases within the water column. This technological gap has in turn led to a scientific gap in our ability to determine the subsurface origin of subsea fluid emissions. Gas releases are commonly found in the marine environment primarily because of naturally occurring seeps and occasionally due to Oil and Gas production activities. There is a need to be able to identify the gas composition and accurately characterize its source (i.e., ongoing microbial activity or thermogenic derived hydrocarbons). However, building a reliable solution which allows this differentiation between thermal and microbial sources in the underwater environment as well as the inference of their subsurface origin requires a multi-disciplinary subsurface workflow coupled comprehensive high-fidelity measurements at the seabed. As one of the front-end building blocks of any robust multi-disciplinary workflow, there is a need for development of an in-situ sensing and sampling capability which allows real-time assessment and geological characterization of the underwater emissions across the upstream industry, from exploration to abandonment. Such a capability would also be complementary to the geohazard and subsurface assessment practices e.g., by reducing lost rig time during interventions by allowing quick characterization of emissions that arise from natural seeps or LOPC (Loss of Primary Containment) events. This paper describes the maturation of a compact underwater in-situ sensing technology deployed from autonomous or tethered underwater vehicles and which enables measurements of gas constituents and their respective isotopes at the seabed.

scholarly journals Reassessing the ratio of glyoxal to formaldehyde as an indicator of hydrocarbon precursor speciation

2015 ◽  
Vol 15 (13) ◽  
pp. 7571-7583 ◽  
Author(s):  
J. Kaiser ◽  
G. M. Wolfe ◽  
K. E. Min ◽  
S. S. Brown ◽  
C. C. Miller ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Global Scale ◽  
Gas Production ◽  
Retrieval Algorithm ◽  
Small Scale ◽  
High Time Resolution ◽  
Ozone Monitoring Instrument ◽  
Oil And Gas Production ◽  
Isoprene Oxidation

Abstract. The yield of formaldehyde (HCHO) and glyoxal (CHOCHO) from oxidation of volatile organic compounds (VOCs) depends on precursor VOC structure and the concentration of NOx (NOx = NO + NO2). Previous work has proposed that the ratio of CHOCHO to HCHO (RGF) can be used as an indicator of precursor VOC speciation, and absolute concentrations of the CHOCHO and HCHO as indicators of NOx. Because this metric is measurable by satellite, it is potentially useful on a global scale; however, absolute values and trends in RGF have differed between satellite and ground-based observations. To investigate potential causes of previous discrepancies and the usefulness of this ratio, we present measurements of CHOCHO and HCHO over the southeastern United States (SE US) from the 2013 SENEX (Southeast Nexus) flight campaign, and compare these measurements with OMI (Ozone Monitoring Instrument) satellite retrievals. High time-resolution flight measurements show that high RGF is associated with monoterpene emissions, low RGF is associated with isoprene oxidation, and emissions associated with oil and gas production can lead to small-scale variation in regional RGF. During the summertime in the SE US, RGF is not a reliable diagnostic of anthropogenic VOC emissions, as HCHO and CHOCHO production are dominated by isoprene oxidation. Our results show that the new CHOCHO retrieval algorithm reduces the previous disagreement between satellite and in situ RGF observations. As the absolute values and trends in RGF observed during SENEX are largely reproduced by OMI observations, we conclude that satellite-based observations of RGF can be used alongside knowledge of land use as a global diagnostic of dominant hydrocarbon speciation.

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.

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