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..

Wellbore method and apparatus for sand and inflow control during well operations

Abstract: A method, system and apparatus associated with the production of hydrocarbons are described. The system includes a wellbore that accesses a subsurface reservoir; a production tubing string disposed within the wellbore; and one or more sand control devices coupled to the production tubing string and disposed within the wellbore. At least one of the sand control devices includes a first tubular member having a permeable section and a non permeable section; a second tubular member disposed within the first tubular member. The second tubular member has a plurality of openings and an inflow control device that each provide a flow path to the interior of the second tubular member. Also, the at least one of the sand control devices includes a sealing mechanism disposed between the first tubular member and the second tubular member. The sealing mechanism is configured to provide a pressure loss during gravel packing operations that is less than the pressure loss during at least some of the production operations.

Hydroalkylation of aromatic hydrocarbons

Abstract: There is described a process and a catalyst for the hydroalkylation of an aromatic hydrocarbon, particularly benzene, wherein the catalyst comprises a first metal having hydrogenation activity and a crystalline inorganic oxide material having a X-ray diffraction pattern including the following d-spacing maxima 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07.

Extraction of Uranium from Wet Process Phosphoric Acid by Liquid Membranes

Abstract: The liquid membrane process can effectively separate and concentrate uranium from wet process phosphoric acid and is economically superior to solvent extraction systems. The paper describes the process, compares it to other extraction schemes, and shows how it can be used for uranium recovery. A mathematical model useful for design purposes is presented and the effect of important variables is discussed.

Finite-difference frequency-domain modeling of viscoacoustic wave propagation in 2D tilted transversely isotropic (TTI) media

Abstract: A 2D finite-difference, frequency-domain method was developed for modeling viscoacoustic seismic waves in transversely isotropic media with a tilted symmetry axis. The medium is parameterized by the P-wave velocity on the symmetry axis, the density, the attenuation factor, Thomsen’s anisotropic parameters δ and ϵ , and the tilt angle. The finite-difference discretization relies on a parsimonious mixed-grid approach that designs accurate yet spatially compact stencils. The system of linear equations resulting from discretizing the time-harmonic wave equation is solved with a parallel direct solver that computes monochromatic wavefields efficiently for many sources. Dispersion analysis shows that four grid points per P-wavelength provide sufficiently accurate solutions in homogeneous media. The absorbing boundary conditions are perfectly matched layers (PMLs). The kinematic and dynamic accuracy of the method wasassessed with several synthetic examples which illustrate the propagation of S-waves excited at t...

Selective Catalytic Olefin Epoxidation with MnII-Exchanged MOF-5

Abstract: Partial substitution of ZnII by MnII in Zn4O(terephthalate)3 (MOF-5) leads to a distorted all-oxygen ligand field supporting a single MnII site, whose structure was confirmed by Mn K-edge X-ray absorption spectroscopy. The MnII ion at the MOF-5 node engages in redox chemistry with a variety of oxidants. With tBuSO2PhIO, it produces a putative MnIV-oxo intermediate, which upon further reaction with adventitious hydrogen is trapped as a MnIII–OH species. Most intriguingly, the intermediacy of the high-spin MnIV–oxo species is likely responsible for catalytic activity of the MnII-MOF-5 precatalyst, which in the presence of tBuSO2PhIO catalyzes oxygen atom transfer reactivity to form epoxides from cyclic alkenes with >99% selectivity. These results demonstrate that MOF secondary building units serve as competent platforms for accessing terminal high-valent metal–oxo species that consequently engage in catalytic oxygen atom transfer chemistry owing to the relatively weak ligand fields provided by the SBU.