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San Ramon, CA, United States

Chevron Corporation is an American multinational energy corporation. One of the successor companies of Standard Oil, it is headquartered in San Ramon, California, and active in more than 180 countries. Chevron is engaged in every aspect of the oil, gas, and geothermal energy industries, including exploration and production; refining, marketing and transport; chemicals manufacturing and sales; and power generation. Chevron is one of the world's largest oil companies; as of 2013, it ranked third in the Fortune Global 500-2014 list of the world's largest companies.Chevron's downstream operations manufacture and sell products such as fuels, lubricants, additives and petrochemicals. The company's most significant areas of operations are the west coast of North America, the U.S. Gulf Coast, Southeast Asia, South Korea, Australia and South Africa. In 2010, Chevron sold an average 3.1 million barrels per day of refined products like gasoline, diesel and jet fuel.Chevron's alternative energy operations include geothermal, solar, wind, biofuel, fuel cells, and hydrogen. In 2011–2013, the company planned to spend at least $2 billion on research and acquisition of renewable power ventures. Chevron has claimed to be the world's largest producer of geothermal energy. In October 2011, Chevron launched a 29-MW thermal solar-to-steam facility in the Coalinga Field to produce the steam for enhanced oil recovery. The project is the largest of its kind in the world. Wikipedia.

Mitri F.,Chevron
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control | Year: 2014

The near-field acoustic scattering from a sphere centered on the axis of a finite Bessel acoustic beam is derived stemming from the Rayleigh-Sommerfeld diffraction surface integral and the addition theorems for the spherical wave and Legendre functions. The beam emerges from a finite circular disk vibrating according to one of its radial modes corresponding to the fundamental solution of a Bessel beam J0. The incident pressure field's expression is derived analytically as a partial-wave series expansion, taking into account the finite size and the distance from the center of the disk transducer. Initially, the scattered pressure by a rigid sphere is evaluated, and backscattering pressure moduli plots as well as 3-D directivity patterns for an elastic PMMA sphere centered on a finite Bessel beam with appropriate tuning of its half-cone angle reveal possible resonance suppression of the sphere only in the zone near the Bessel transducer. Moreover, the analysis is extended to derive the mean spatial incident and scattered pressures at the surface of a rigid circular receiver of infinitesimal thickness. The transducer, sphere, and receiver are assumed to be coaxial. Some applications can result from the present analysis because all physically realizable Bessel beam sources radiate finite sound beams as opposed to waves of infinite extent. © 1986-2012 IEEE. Source

Creek J.L.,Chevron
Energy and Fuels | Year: 2012

A primary focus of flow assurance engineers during project development is the prevention and management of gas hydrate formation in pipelines. Historically, engineers have focused on hydrate formation prevention by injecting sufficient quantities of thermodynamic inhibitors to "shift" the hydrate stability region outside of the range of pressure and temperature operating conditions. However, as developments of hydrocarbon production occur in ever more extreme environments, the practice of complete prevention of hydrate formation may become prohibitively expensive because of the large amounts of inhibitor required. The example of high methanol dosage in equal volumes of inhibitor for water implies a cost of $84 per barrel of water produced at a methanol cost of $2/gallon. As the produced water volume increases during field life, the operators may not be able to pay for hydrate inhibition even with $100 per barrel of oil. The past decade has seen intensive research to discover strategies for transitioning from costly prevention measures to more cost-effective mitigation and flow-management measures. Such practices would allow for the possibility of hydrate formation in flow lines yet would involve managing the flow in the production system such that these formed hydrates would be continuously and safely transported along with the production fluids. This could reduce and, in some cases, eliminate the need for thermodynamic inhibition. Early attempts at moving from hydrate prevention to hydrate management focused on so-called "low-dosage hydrate inhibitors" (LDHIs), generally subdivided into kinetic hydrate inhibitors (KHIs) and anti-agglomerate chemicals (AAs). These chemicals could alter the formation rate of hydrates and/or limit the total growth while dispersing the hydrates in the hydrocarbon liquid phase. While these chemicals can aid in the management of hydrate formation, their range of application has typically been limited to a maximum water cut of less than 60%. More recently, researchers have sought methods to physically manage hydrate formation in a more "holistic" manner, focusing on the natural solids-carrying capability of the produced fluids and important interactions among any formed hydrates. These methods could be deployed if one had detailed knowledge of how blockages are formed and how fluid/emulsion properties affect hydrate transport. This presentation will discuss insights into the mechanisms of blockage formation through flow loop testing and accompanying simulations. It will also discuss how this knowledge has enhanced the ability of operators to successfully design production strategies to produce reservoir fluids in deepwater operations. © 2012 American Chemical Society. Source

Zones S.I.,Chevron
Microporous and Mesoporous Materials | Year: 2011

In this presentation I will attempt to describe the expansion of new materials in the microporous metal oxide world and then some of the boundary conditions which must be met in trying to scale them up. The field of zeolite and mesoporous materials has seen considerable numbers of new discoveries in recent years as the chemistries explored have continued to be creative. In what follows, I will survey some of the concepts used in arriving at new structures. Then I will follow-up with some views of issues that need to be faced in being able to generate these materials on a large scale and in an affordable fashion. This latter feature, of course, has some flexibility in terms of what the value of the process application will be, how strict the environmental regulations are in regard to both the process application and the catalyst production environment, and finally, costs of raw materials and production at the manufacturing site. © 2011 Published by Elsevier Inc. Source

Mitri F.G.,Chevron
Annals of Physics | Year: 2015

This investigation shows that a scalar Bessel beam can be transformed into the non-paraxial complex-source-point cylindrical wave (CSPCW). High-order CSPCW solutions, termed here high-order quasi-Gaussian cylindrical beams, which exactly satisfy the Helmholtz equation, are derived analytically. Moreover, partial-derivatives of the high-order CSPCW solutions satisfy the Helmholtz equation. In addition, the CSPCW solutions satisfy the nonrelativistic Schrödinger equation within standard quantum mechanics, thus, the results can be used in the description of elementary particle/matter motion and related applications in quantum scattering theory. Furthermore, the analysis is extended to the case of vector beams in which the components of the electromagnetic (EM) field are obtained based on different polarizations of the magnetic and electric vector potentials, which exactly satisfy Maxwell's vectorial equations and Lorenz' gauge condition. An attractive feature of the high-order solutions is the rigorous description of strongly focused (or strongly divergent) cylindrical wave-fields without any approximations, nor the need for numerical methods. Possible applications are in beam-forming design using high-aperture or collimated cylindrical laser/electron quasi-Gaussian beams in imaging microscopy, particle manipulation, optical tweezers, and the study of the scattering, and radiation forces on objects. © 2015 Elsevier Inc. Source

The optical theorem for plane waves is recognized as one of the fundamental theorems in optical, acoustical and quantum wave scattering theory as it relates the extinction cross-section to the forward scattering complex amplitude function. Here, the optical theorem is extended and generalized in a cylindrical coordinates system for the case of 2D beams of arbitrary character as opposed to plane waves of infinite extent. The case of scalar monochromatic acoustical wavefronts is considered, and generalized analytical expressions for the extinction, absorption and scattering cross-sections are derived and extended in the framework of the scalar resonance scattering theory. The analysis reveals the presence of an interference scattering cross-section term describing the interaction between the diffracted Franz waves with the resonance elastic waves. The extended optical theorem in cylindrical coordinates is applicable to any object of arbitrary geometry in 2D located arbitrarily in the beam's path. Related investigations in optics, acoustics and quantum mechanics will benefit from this analysis in the context of wave scattering theory and other phenomena closely connected to it, such as the multiple scattering by a cloud of particles, as well as the resulting radiation force and torque. © 2015 Elsevier B.V. All rights reserved. Source

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