Preprints
Filtering by Subject: Oil, Gas, and Energy
Global Liquefied Natural Gas Expansion Exceeds Demand for Coal-to-gas Switching in Paris Compliant Pathways
Published: 2020-12-04
Subjects: Oil, Gas, and Energy, Sustainability
The shift from coal to natural gas (NG) in the power sector has led to significant reductions in carbon emissions. The shale gas revolution that led to this shift is now fueling a global expansion in liquefied natural gas (LNG) export infrastructure. In this work, we assess the viability of LNG expansion to reduce global carbon emissions through coal-to-gas switching in the power sector under [...]
A quantitative assessment of the hydrogen storage capacity of the UK continental shelf
Published: 2020-11-20
Subjects: Oil, Gas, and Energy
Increased penetration of renewable energy sources and decarbonisation of the UK's gas supply will require large-scale energy storage. Using hydrogen as an energy storage vector, we estimate that 150 TWh of seasonal storage is required to replace seasonal variations in natural gas production. Large-scale storage is best suited to porous rock reservoirs. We present a method to quantify the hydrogen [...]
Closing the gap: Explaining persistent underestimation by US oil and natural gas production-segment methane inventories
Published: 2020-11-03
Subjects: Environmental Indicators and Impact Assessment, Oil, Gas, and Energy
Methane (CH4) emissions from oil and natural gas (O&NG) systems are an important contributor to greenhouse gas emissions. In the United States, recent synthesis studies of field measurements of CH4 emissions at different spatial scales are ~1.5x-2x greater compared to official greenhouse gas inventory (GHGI) estimates, with the production-segment as the dominant contributor to this divergence. [...]
The Global Warming Potential Misrepresents the Physics of Global Warming Thereby Misleading Policy Makers
Published: 2020-10-25
Subjects: Atmospheric Sciences, Environmental Sciences, Oil, Gas, and Energy
The Global Warming Potential (GWP) is a widely used metric used to compare the climate change effects of various greenhouse gases. Although GWP has an established role in international climate agreements, GWP does not, in general, describe any specific identifiable impact of greenhouse gas emissions on climate. It is argued here that GWP is unphysical, unintuitive, arbitrary, ignores the time [...]
The Paradox of Increasing Initial Oil Production but Faster Decline Rates in Fracking the Bakken Shale: Implications for Long Term Productivity of Tight Oil Plays
Published: 2020-10-21
Subjects: Oil, Gas, and Energy, Petroleum Engineering
In the US, tight oil is the largest source of liquid hydrocarbons and has driven the country to become the world’s largest oil producer. Eventually many countries will likely be producing very large quantiles of tight oil. However, how robust is tight oil production? The answer to this question will have an impact on the future geographic spread of oil production and will have geopolitical [...]
Bridging the gap between geophysics and geology with Generative Adversarial Networks (GANs)
Published: 2020-08-17
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Databases and Information Systems, Earth Sciences, Environmental Monitoring, Environmental Sciences, Geology, Geomorphology, Geophysics and Seismology, Natural Resource Economics, Oil, Gas, and Energy, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Water Resource Management
Inverse mapping from geophysics to geology is a difficult problem due to the inherent uncertainty of geophysical data and the spatially heterogeneous patterns (structure) in geology. We describe GANSim, a type of generative adversarial networks (GANs) that discovers the mapping between remotely-sensed geophysical information and geology with realistic patterns, with a specially designed loss [...]
Fracture mechanics of rate-and-state faults and fluid injection induced slip
Published: 2020-07-08
Subjects: Earth Sciences, Engineering, Environmental Sciences, Geophysics and Seismology, Oil, Gas, and Energy, Physical Sciences and Mathematics, Physics
Propagation of a slip transient on a fault with rate-and-state dependent friction resembles a fracture which near tip region is characterized by large departure of the slip velocity and fault strength from the steady-state sliding. We develop a near tip solution to describe this unsteady dynamics, and obtain the fracture energy Gc, dissipated in overcoming strength-excursion away from [...]
An agent-based model for estimating emissions reduction equivalence among leak detection and repair programs
Published: 2020-07-02
Subjects: Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
Alternative leak detection and repair (alt-LDAR) programs are being introduced by regulators in North America to provide flexibility in how oil and gas producers manage their fugitive methane emissions. However, emissions reduction equivalence must be established between a proposed program and a regulatory standard. We present LDAR-Sim, an open-source, agent-based numerical model for estimating [...]
Turbulent flow effects in a slickwater fracture propagation in permeable rock
Published: 2020-06-18
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Oil, Gas, and Energy, Physical Sciences and Mathematics, Volcanology
This work is devoted to an analysis of the near-tip region of a hydraulic fracture driven by slickwater in a permeable saturated rock. We consider a steady-state problem of a semi-infinite fracture propagating with constant velocity. The host rock is elastic and homogeneous, and fracture propagates according to linear elastic fracture mechanics. The fluid exchange between the fracture and [...]
Methane concentrations in streams reveal gas leak discharges in regions of oil, gas, and coal development
Published: 2020-06-18
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Geochemistry, Oil, Gas, and Energy, Physical Sciences and Mathematics, Water Resource Management
As natural gas has grown in importance as a global energy source, leakage of methane (CH4) from wells has sometimes been noted. Leakage of this greenhouse gas is important because it affects groundwater quality and, when emitted to the atmosphere, climate. We hypothesized that streams might be most contaminated by CH4 in the northern Appalachian Basin in regions with the longest history of [...]
A radial hydraulic fracture with pressure-dependent leak-off
Published: 2020-05-07
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Oil, Gas, and Energy, Physical Sciences and Mathematics, Volcanology
This paper investigates the problem of a radial (or penny-shaped) hydraulic fracture propagating in a permeable reservoir. In particular, we consider the fluid exchange between the crack and ambient porous media as a pressure-dependent process. In most of the existing models, the fluid exchange process is represented as one-dimensional pressure-independent leak-off described by Carters law. We [...]
Cascading Failure Phenomenon in the Multi-Stage Hydraulically Fractured Wells
Published: 2020-04-14
Subjects: Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
The phenomenon of cascading fracture failure during flowback and initial production from a horizontal multistage hydraulically fractured well is introduced, described, and investigated. First, a simplified analytical model of production from such well is built. This model allows evaluating a range of systems parameters through which the cascading failure evolves and performing a sensitivity study [...]
Policy Bridge: Air Quality Impacts from Oil and Natural Gas Development in Colorado
Published: 2019-12-13
Subjects: Environmental Education, Environmental Health and Protection, Environmental Monitoring, Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
The rise of hydraulic fracturing techniques has fostered rapid growth of oil and natural gas extraction in areas across the United States. In the Denver-Julesburg Basin (DJB), which mostly overlaps with Weld County in the Northern Colorado Front Range (NCFR) north of the City of Denver Metropolitan Area (DMA), the well drilling has increasingly approached, and in many instances moved into urban [...]
Detection and temperature estimation of gas flares with nocturnal Landsat OLI
Published: 2019-11-02
Subjects: Earth Sciences, Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
Natural gas flaring is a worldwide polluting activity carried out during oil production. Satellite imagery has emerged as a low-cost, objective tool to measure and monitor gas flaring. Since 2012, hectometre-resolution infrared imagery from the Suomi NPP VIIRS sensor has been used to operationally monitor global gas flaring (Elvidge et al. 2016). Since 2013, nocturnal acquisitions of Landsat 8 [...]
Verifying pore network models of imbibition in rocks using time-resolved synchrotron imaging
Published: 2019-10-25
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Oil, Gas, and Energy, Physical Sciences and Mathematics
At the pore scale, slow invasion of a wetting fluid in porous materials is often modelled with quasi-static approximations which only consider capillary forces in the form of simple pore filling rules. The appropriateness of this approximation, often applied in pore network models, is contested in literature, reflecting the difficulty of predicting imbibition relative permeability with these [...]