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.

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.

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 Hydrogen sulfide formation in oil and gas

2016 ◽  
Vol 94 (4) ◽  
pp. 406-413 ◽  
Author(s):  
Robert A. Marriott ◽  
Payman Pirzadeh ◽  
Juan J. Marrugo-Hernandez ◽  
Shaunak Raval
Keyword(s):  
Hydrogen Sulfide ◽  
Sulfate Reduction ◽  
Oil Sands ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Ionic Strength Effect ◽  
Thermochemical Sulfate Reduction ◽  
Fracture Fluid

Hydrogen sulfide (H2S) can be a significant component of oil and gas upstream production, where H2S can be naturally generated in situ from reservoir biomass and from sulfate-containing minerals through microbial sulfate reduction and (or) thermochemical sulfate reduction. On the other hand, the technologies employed in oil and gas production, especially from unconventional resources, also can contribute to generation or delay of appearance of H2S. Steam-assisted gravity drainage and hydraulic fracturing used in production of oil sands and shale oil/gas, respectively, can potentially convert the sulfur content of the petroleum into H2S or contribute excess amounts of H2S during production. A brief overview of the different classes of chemical reactions involved in the in situ generation and release of H2S is provided in this work. Speciation calculations and reaction mechanisms are presented to explain why thermochemical sulfate reduction progresses at faster rates under low pH. New studies regarding the degradation of a hydraulic fracture fluid additive (sodium dodecly sulfate) are reported for T = 200 °C, p = 17 MPa, and high ionic strengths. The absence of an ionic strength effect on the reaction rate suggests that the rate-limiting step involves the reaction of neutral species, such as elemental sulfur. This is not the case with other thermochemical sulfate reduction studies at T > 300 °C. These two different kinetic regimes complicate the goal of extrapolating laboratory results for field-specific models for H2S production.

scholarly journals Declining methane emissions and steady, high leakage rates observed over multiple years in a western US oil/gas production basin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
John C. Lin ◽  
Ryan Bares ◽  
Benjamin Fasoli ◽  
Maria Garcia ◽  
Erik Crosman ◽  
...  
Keyword(s):  
Natural Gas ◽  
Oil And Gas ◽  
Methane Emissions ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Production Region ◽  
Main Component ◽  
Oil Gas ◽  
The U.S

AbstractMethane, a potent greenhouse gas, is the main component of natural gas. Previous research has identified considerable methane emissions associated with oil and gas production, but estimates of emission trends have been inconsistent, in part due to limited in-situ methane observations spanning multiple years in oil/gas production regions. Here we present a unique analysis of one of the longest-running datasets of in-situ methane observations from an oil/gas production region in Utah’s Uinta Basin. The observations indicate Uinta methane emissions approximately halved between 2015 and 2020, along with declining gas production. As a percentage of gas production, however, emissions remained steady over the same years, at ~ 6–8%, among the highest in the U.S. Addressing methane leaks and recovering more of the economically valuable natural gas is critical, as the U.S. seeks to address climate change through aggressive greenhouse emission reductions.

scholarly journals Daily Satellite Observations of Methane from Oil and Gas Production Regions in the United States

2020 ◽  
Author(s):  
Pieternel Levelt ◽  
Pepijn Veefkind ◽  
Esther Roosenbrand ◽  
John Lin ◽  
Jochen Landgraf ◽  
...  
Keyword(s):  
United States ◽  
Natural Gas ◽  
Oil And Gas ◽  
The United States ◽  
Methane Emissions ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Natural Gas Production ◽  
Oil And Natural Gas

<p>Production of oil and natural gas in North America is at an all-time high due to the development and use of horizontal drilling and hydraulic fracturing. Methane emissions associated with this industrial activity are a concern because of the contribution to climate radiative forcing. We present new measurements from the space-based TROPOspheric Monitoring Instrument (TROPOMI) launched in 2017 that show methane enhancements over production regions in the United States. Using methane and NO<sub>2</sub> column measurements from the new TROPOMI instrument, we show that emissions from oil and gas production in the Uintah and Permian Basins can be observed in the data from individual overpasses. This is a vast improvement over measurements from previous satellite instruments, which typically needed to be averaged over a year or more to quantify trends and regional enhancements in methane emissions. In the Uintah Basin in Utah, TROPOMI methane columns correlated with in-situ measurements, and the highest columns were observed over the deepest parts of the basin, consistent with the accumulation of emissions underneath inversions. In the Permian Basin in Texas and New Mexico, methane columns showed maxima over regions with the highest natural gas production and were correlated with nitrogen-dioxide columns at a ratio that is consistent with results from in-situ airborne measurements. The improved detail provided by TROPOMI will likely enable the timely monitoring from space of methane and NO2 emissions associated with regular oil and natural gas production.</p>

scholarly journals Systematic Experimental Investigation on In-Situ Self-Adaptive Sealing Property of Composite Pressure-Activated Sealant for Curing Minor Tubular Leaks

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5597
Author(s):  
Lin Xu ◽  
Xiaohe Huang ◽  
Xin Huang ◽  
Jie Xu ◽  
Xijin Xing ◽  
...  
Keyword(s):  
Size Distribution ◽  
Oil And Gas ◽  
Coupling Model ◽  
Gas Production ◽  
Phase System ◽  
Oil And Gas Production ◽  
Sustained Casing Pressure ◽  
Sealing Materials ◽  
Self Adaptive

Curing minor leaks and restoring the integrity of a wellbore in a safe and economical way is always challenging in oil and gas production. In this work, a composite pressure-activated sealant, combined with liquid and solid sealing materials, was prepared via the demulsification approach. The structure, morphology, and size distribution of key particulates in the sealant were examined, and the in-situ self-adaptive sealing property was examined with a specially design dynamic sealing detector. The results indicated that the pressure-activated sealant was a multi-dispersed phase system, and the dispersed colloid particles were regular in shape and had a narrow size distribution of 300–400 μm. The solid sealing materials were introduced to construct a composite pressure-activated sealant, and the sealing capability can be markedly reinforced by cooperativity of liquid and solid sealing materials. A mechanochemical coupling model was put forward to rationalize the dynamic sealing process. Finally, such sealant system was employed in a certain offshore gas well with sustained casing pressure to verify its applicability in minor defect repairs.

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.

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