ExxonMobil

About: ExxonMobil is a company organization based out in Irving, Texas, United States. It is known for research contribution in the topics: Catalysis & Polymer. The organization has 16969 authors who have published 23758 publications receiving 535713 citations. The organization is also known as: Exxon Mobil Corporation & Exxon Mobil Corp..

Use of multiattribute transforms to predict log properties from seismic data

Abstract: We describe a new method for predicting well‐log properties from seismic data. The analysis data consist of a series of target logs from wells which tie a 3-D seismic volume. The target logs theoretically may be of any type; however, the greatest success to date has been in predicting porosity logs. From the 3-D seismic volume a series of sample‐based attributes is calculated. The objective is to derive a multiattribute transform, which is a linear or nonlinear transform between a subset of the attributes and the target log values. The selected subset is determined by a process of forward stepwise regression, which derives increasingly larger subsets of attributes. An extension of conventional crossplotting involves the use of a convolutional operator to resolve frequency differences between the target logs and the seismic data. In the linear mode, the transform consists of a series of weights derived by least‐squares minimization. In the nonlinear mode, a neural network is trained, using the selected att...

Catalytic synthesis of hydrocarbons from carbon monoxide and hydrogen

Abstract: The increasing demand for energy, coupled with the uncertainty and expense of crude oil imports, has renewed interest in the production of fuels and chemicals from hydrogen-deficient materials. These energy sources such as coal, residua, oil shale, and tar sands can be gasified with steam and oxygen to produce a gas containing large quantities of carbon monoxide and hydrogen. Once methane is removed from this CO/H2 mixture it is purified to remove S poisons and then reacted over a catalyst to produce a variety of organic products. The synthesis of hydrocarbon products, with the exception of methane, is commonly referred to as the Fischer-Tropsch synthesis reaction.

Dynamical fluctuations of droplet microemulsions and vesicles

Abstract: The hydrodynamic fluctuations of nearly spherical vesicles and microemulsion droplets are considered. The incompressibility of the enclosed fluid and surfactant or lipid layer imposes a constraint of constant droplet volume and area on the fluctuations. These overdamped modes, driven by bending energy and damped by viscosity of the surrounding fluids, change the shape of the surface and may scatter neutrons or light. A dynamical structure factor S(q,t) is computed and a first frequency moment at fixed wave number ${\ensuremath{\omega}}_{\mathrm{char}(\mathrm{q}}$) obtained. In the limit of a stiff droplet at fixed ``excess area,'' a new mode is obtained ---an overdamped oscillation among ellipsoidal shapes about the minimum-energy (usually prolate) shape. Prospects for observing this fluctuation are discussed.

Elasticity of Compressed Emulsions.

Abstract: The elastic shear modulus of monodisperse emulsions is shown to exhibit a universal dependence on droplet volume fraction $\ensuremath{\varphi}$ when scaled by the Laplace pressure of the droplets, increasing as $\ensuremath{\varphi}(\ensuremath{\varphi}\ensuremath{-}{\ensuremath{\varphi}}_{c})$, where ${\ensuremath{\varphi}}_{c}\ensuremath{\approx}0.635$, the value of random close packing of solid spheres. Surprisingly the osmotic pressure required to compress the emulsions to increase $\ensuremath{\varphi}$ is nearly the same as the shear modulus over a large range of volume fraction, while the bulk osmotic modulus differs significantly. Models based on the structural disorder of the emulsions are discussed to account for these data.