Mobil

About: Mobil is a based out in . It is known for research contribution in the topics: Catalysis & Zeolite. The organization has 7085 authors who have published 10642 publications receiving 237497 citations. The organization is also known as: Socony-Vacuum Oil Company & Standard Oil Company of New York.

Flow of viscoelastic fluids through porous media

Abstract: Local volume averaging of the equations of continuity and of motion over a porous medium is discussed. For steady state flow such that inertial effects can be neglected, a resistance transformation is introduced which in part transforms the local average velocity vector into the local force per unit volume which the fluid exerts on the pore walls. It is suggested that for a randomly deposited, although perhaps layered, porous structure this resistance transformation is invertible, symmetric, and positive-definite. Finally, for an isotropic porous structure (the proper values of the resistance transformation are all equal and are termed the resistance coefficient) and an incompressible fluid, the functional dependence of the resistance coefficient is discussed with the Buckingham-Pi theorem used for an Ellis model fluid, a power model fluid, a Newtonian fluid, and a Noll simple fluid. Based on the discussion of the Noll simple fluid, a suggestion is made for the correlation and extrapolation of experimental data for a single viscoelastic fluid in a set of geometrically similar porous structures.

Formation and Aging of Incipient Thin Film Wax-Oil Gels

Abstract: A fundamental study of the deposition and aging of a thin incipient wax-oil gel that is formed during the flow of waxy oils in cooled pipes was performed. The solubility of high molecular weight paraffins in naphthenic, aromatic or paraffinic solvents is very low and decreases rapidly with decreasing temperature. This property of the paraffins leads to the formation of gels of complex morphology that deposit on the cold walls of the subsea pipelines during the flow of waxy crudes. This deposition reduces the pipe diameter and decreases the flow capacity of the pipe. These wax-oil gels contain a large fraction of oil trapped in a 3-D network structure of the wax crystals that behaves as a porous medium. After the incipient gel is formed, wax molecules continue to diffuse into this structure, thereby increasing its wax content. A model system of wax and oil mixture was used to understand the aging process of the wax-oil gels, which hardens the wax deposit with time. To understand the physics of the aging process for incipient thin-film deposits, a series of laboratory flow loop experiments was performed. The aging process was a counterdiffusion phenomenon with a critical carbon number above which wax molecules diffuse into the gel deposit and below which oil molecules diffuse out of the deposit. The aging rate of the gel deposit depends on the oil flow rate and the wall temperature. A mathematical model developed predicted the growth and wax content of the gel deposit on externally cooled pipe walls. The theory agreed with experiments excellently for thin gels.

Fan-deltas and braid deltas: Varieties of coarse-grained deltas

Abstract: Two types of coarse-grained deltas are recognized: fan-deltas and braid deltas. Fan-deltas are gravel-rich deltas formed where an alluvial fan is deposited directly into a standing body of water from an adjacent highland. They occupy a space between the highland (usually a fault-bounded margin) and the standing body of water. In contrast, braid deltas (here introduced) are gravel-rich deltas that form where a braided fluvial system progrades into a standing body of water. Braid deltas have no necessary relationship with alluvial fans, as exemplified by fluvioglacial braid deltas. Braid deltas have previously been classified as fan-deltas even though the geomorphic and sedimentologic settings of the two systems can be vastly different. Braid deltas are a common present-day geomorphic feature and are abundant in the geological record. Fan-deltas and braid deltas can be distinguished in the rock record by distinctive subaerial components of these depositional systems; the shoreline and subaqueous components of both are similar. Fan-delta sequences have a subaerial component that is an alluvial-fan facies comprising interbedded sheetflood, debris-flow, and braided-channel deposits. Fan-deltas produce small (a few tens of square kilometres), wedge-shaped bodies of sediment, commonly displaying high variability in paleocurrent patterns and abrupt changes in facies. The deposits are generally very coarse grained (with large out-sized clasts), very poorly sorted, matrix-rich, polymictic, heterolithic, partially cemented by penecontemporaneous carbonate, and have low porosity and permeability. Braid-deltas, in contrast, have a subaerial component consisting entirely of braided-river or braidplain facies. Their deposits display better sorting, roundness, and clast orientation than do fan-delta sediments; they lack a muddy matrix; they display size grading and bar migration; they commonly have a sheet geometry with high lateral continuity (tens to hundreds of square kilometres); and they exhibit moderate to high porosity and permeability. Valuable paleogeographic and tectonic information concerning the proximity of highlands and major fault zones may be misinterpreted or lost if these two coarse-grained deltaic systems are not differentiated.

Diamondoid hydrocarbons as indicators of natural oil cracking

Abstract: Oil cracking—the thermal breakdown of heavy hydrocarbons to smaller ones—takes place within oil-bearing rock formations at depths commonly accessed by commercial oil wells. The process ultimately converts oil into gas and pyrobitumen, and thus limits the occurrence of petroleum and the success of exploration. Thermal cracking of liquid petroleum increases with depth until it reaches completion at the so-called ‘oil deadline’, which is generally placed1,2 at around 5 km depth and at temperatures of 150–175 °C. However, cracking experiments3,4,5,6,7,8 and the discovery of relatively ‘hot’ oil reservoirs9,10 imply that petroleum is thermally more stable than previously assumed; in fact it has been suggested that liquid petroleum might persist at temperatures reaching6,11,12,13 or even exceeding3,14 200 °C. But reliable estimates of the extent of oil cracking and the depth at which it occurs in any given reservoir are difficult to obtain. Here we demonstrate that the relative abundance of diamondoids, a class of petroleum compounds whose unique thermal stability leads to their progressive concentration during cracking15, can be used to identify the occurrence and estimate the extent of oil destruction and the oil deadline in a particular basin. We are also able to identify oils consisting of mixtures of high- and low-maturity components, demonstrating that our method yields valuable information on the cracking and mixing processes affecting petroleum systems.

Crystalline zeolite and method of preparing same

Abstract: A new crystalline zeolite, designated ZSM-35, a method of making same and the use thereof in catalytic conversion of hydrocarbons is the subject of this application. The new zeolite has a composition, in the anhydrous state, expressed in terms of mole ratios of oxides as follows: (0.3-2.5)R.sub.2 O:(0-0.8)M.sub.2 O:Al.sub.2 O.sub.3 :>8 SiO.sub.2 wherein R is an organic nitrogen-containing cation and M is an alkali metal cation, and is characterized by a specified X-ray powder diffraction pattern.