Analysis of Physical Structure and Chemical Composition of Oil-Water Transition Layer in Oil Gathering and Transportation System

2013 ◽  
Vol 652-654 ◽  
pp. 2566-2569
Author(s):  
Dan Dan Yuan ◽  
Hong Jun Wu ◽  
Hai Xia Sheng ◽  
Bao Hui Wang ◽  
Xin Sui

he existence of oil-water transition layer brings a great trouble to the dehydration of oil gathering and transportation system. It leads to raising the electric current of dehydrator and becoming worse of the deoiling and dehydrating properties of the treatment equipment, resulting in the serious influences on oil recovery. For the efficient treatment of the transition layer, it is necessary clearly to understand the structure and composition of the layer. In this paper, the physical structure and chemical composition of the layer were systematically, layer by layer and phase by phase, analyzed by modern instrumental methods The results show that (1)the layer is an emulsion which is composed of oil, water and suspended solids. The water phase has characteristics of weak alkaline,high salinity and viscous polymer. The oil phase contains many natural emulsifiers such as colloid, asphaltene and so on. The solid phase mainly concludes FeS particle which plays a decisive role in suspended solids; (2) the typical transition layer is composed of water and oil which accounts for above 90%, the content of solid impurity, which controls the emulsion of the layer, is less than 10%. Compared with oil phase, the water content of typical transition layer is larger with the density of 0.9~1.0 g/L and high freezing point. The analytical data can be adopted for the treatment of oil-water transition layer and smoothly run operations for oil gathering and transportation.

2013 ◽  
Vol 652-654 ◽  
pp. 749-752
Author(s):  
Dan Dan Yuan ◽  
Hong Jun Wu ◽  
Hai Xia Sheng ◽  
Xin Sui ◽  
Bao Hui Wang

In order to meet the need of separating oil from water in the settling tank of the oilfield, ClO2 treatment for oil-water transition layer in settling tank is introduced. The field test displayed that the technique was achieved by a good performance. For understanding the oxidation and mechanism, compositions of oil-water transition layer were comparatively studied for before/after ClO2-treatment in this paper.The experimental results show that the compositions before and after ClO2-treatment, including physical structure and chemical composition, were varied in the great extension. The physical structure, consisting of water, oil and solid phase, was reduced to less than 5% of water and 0.5% of solid particle and increased to 95% of oil in layer compared with before-treatment, easily leading to clearly separating water from oil. The chemical composition of iron sulfide and acid insoluble substance in solid phase was decreased to more than 90% while the carbonate was reduced more than 70% . After the treatment, the viscosity reduction of the water phase in the layer was reached to 50% after oxidation demulsification with ClO2. The chemistry was discussed based on the principles and experiments. Due to ClO2 destroying (oxidizing) the rigid interface membrane structure which is supported by natural surfactant, polymer and solid particles with interface-active materials, the action accelerates the separating of water and oil and sedimentation of insoluble residue of acid in the layer. By demonstrating the experimental data and discussion, we can effectively control the oxidation performance of chlorine dioxide, which is very meaningful for oilfield on the aspect of stable production of petroleum.


1996 ◽  
Vol 33 (9) ◽  
pp. 117-125 ◽  
Author(s):  
Emmanuelle Aiguier ◽  
Ghassan Chebbo ◽  
Jean-Luc Bertrand-Krajewski ◽  
Peter Hedges ◽  
Naomi Tyack

Recently, research has shown that a settling process is an efficient treatment for the removal of suspended solids from storm sewage. In order to design settling tanks, there is a need to determine the settling velocity characteristics of these solids. Devices and test methods for measuring settling velocities of solids in storm sewage have been developed by researchers. A literature review has revealed that the settling velocity profiles obtained with some methods (Chebbo, 1992), (Michelbach and Wohrle, 1993) and (Tyack et al., 1993) are very different. In order to explain why the results are different and to quantify the influence of the experimental procedure on the settling velocity grading curves, we have compared the selected methods when tested with the same sample and we have studied the effects of the conservation of the sample before the test, of the concentration of solids in the device and of the nature of the water on the settling velocity profiles. The results of the comparative tests indicate that the settling velocities are significantly lower with both the Cergrene and Aston methods than with the UFT test procedure. Moreover, the study has shown that the settling characteristics of solids change with time, that the use of sewage liquor rather than demineralised water or drinking water can change the results of the measurement and that the higher the concentration of solids, the greater the velocity of settled particles.


1972 ◽  
Vol 45 ◽  
pp. 265-270
Author(s):  
L. M. Shul'man

The probable parent-molecules of radicals such as C3 and N2+ are discussed, and it is concluded that cometary nuclei may contain complicated organic molecules, such as C3H4, CH2N2, and C4H2. It is suggested that these molecules are formed by radiation synthesis in solid phase. In a time interval of order 107 to 109 yr bombardment from cosmic rays would be expected to transform the chemical composition to a depth of 1 m. Solar cosmic rays do not penetrate as far, and as a result the surface layer of the nucleus can be enriched with unsaturated hydrocarbons. After a critical concentration of this explosive material is reached a further burst of solar cosmic rays can initiate an explosion and thus an outburst in the comet's brightness. This mechanism is the only one advanced to date that can explain the synchronism of the energy output over the whole nuclear surface.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 821
Author(s):  
Sergey Khrapak ◽  
Alexey Khrapak

The Prandtl number is evaluated for the three-dimensional hard-sphere and one-component plasma fluids, from the dilute weakly coupled regime up to a dense strongly coupled regime near the fluid-solid phase transition. In both cases, numerical values of order unity are obtained. The Prandtl number increases on approaching the freezing point, where it reaches a quasi-universal value for simple dielectric fluids of about ≃1.7. Relations to two-dimensional fluids are briefly discussed.


Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 108 ◽  
Author(s):  
Alberto Mannu ◽  
Gina Vlahopoulou ◽  
Paolo Urgeghe ◽  
Monica Ferro ◽  
Alessandra Del Caro ◽  
...  

The chemical composition and the color of samples of waste cooking oils (WCOs) were determined prior to and after filtration on two different pads of bentonite differing in particle size. The volatile fraction was monitored by headspace solid-phase microextraction (HS-SPME) coupled with gas-chromatography, while the variation of the composition of the main components was analyzed by 1H NMR. Both techniques allowed the detection of some decomposition products, such as polymers, terpenes, and derivatives of the Maillard process. The analysis of the chemical composition prior to and after bentonite treatment revealed a tendency for the clays to retain specific chemical groups (such as carboxylic acids or double bonds), independent of their particle size. A pair comparison test was conducted in order to detect the sensory differences of the intensity of aroma between the WCO treated with the two different bentonites. In addition, characterization of the bentonite by means of powder X-ray diffraction (XRD) and thermogravimetric measurements (TG) was performed.


2018 ◽  
Vol 18 (9) ◽  
pp. 6331-6351 ◽  
Author(s):  
Wing-Sy Wong DeRieux ◽  
Ying Li ◽  
Peng Lin ◽  
Julia Laskin ◽  
Alexander Laskin ◽  
...  

Abstract. Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ∼ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg∕T) as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ∼ 10 (±1.7) as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon–Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ), and the Gordon–Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.


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