Study of Oil-Bearing Drill Cuttings Cleaning and De-Oiling Treatment Method for Shale Gas Reservoirs

Due to its extensive use in shale gas exploration and development,oil-based drilling fluids generate large amounts of oil-bearing drill cuttings during the drilling process.The large amount of oil-bearing drill cuttings generated during the drilling process can lead to serious secondary contamination.In this study,a wetting agent FSC-6 with good hydrophobic and oleophobic properties was synthesized to construct an efficient oil removal system.For the first time,the mechanism of this system was analyzed by using the theory of adhesion function,interfacial tension and wettability.At the same time,a combined acoustic-chemical treatment process was applied to the wastewater and slag generated after the cleaning of the oil-bearing drill cuttings.The experimental results show that the application of this pollution-free technology can effectively solve the environmental pollution and resource recovery problems of oil-bearing drill cuttings.It meets the standard of drilling chips with oil content less than 2%in SY/T7422-2018“Oil-based drilling fluid drilling chips treatment system for oil and gas drilling equipment”.

Development of an atmospheric fluorocarbon plasma jet generated by pulse modulated microwave discharge

Atmospheric fluorocarbon plasma plays an important role in the surface modification of insulating materials like polymers.The existing fluorocarbon plasma is usually generated by dielectric barrier discharge,which has a low concentration of reactive species and may cause insufficient surface fluorination.This work attempts to develop an atmospheric fluorocarbon plasma jet using a coaxial transmission line resonator by microwave discharge with locally enhanced electric field and high density.The gas temperature is reduced by pulse modulation technology.Three kinds of working gases,pure CF_(4),Ar/CF_(4)and He/CF_(4),are utilized to generate the atmospheric microwave fluorocarbon plasma jet.The discharge images,optical emission spectra,electron densities and gas temperatures are studied experimentally.The results show that the Ar/CF_(4)plasma jet has the best comprehensive performance,such as strong discharge intensity and controllable gas temperature.The electron density of the Ar/CF_4plasma jet has a magnitude of 10~(20)m^(-3),indicating a higher density than that of the frequently used dielectric barrier discharge.With the other conditions unchanged,the gas temperature at the end of the Ar/CF_(4)plasma jet can be reduced from 410.2 to 347.3 K by decreasing the duty cycle of the modulated pulse from 0.5 to 0.1.Thence,the microwave Ar/CF_(4)plasma jet is considered to be a promising fluorocarbon plasma source for surface fluorination of polymers.

The effects of perfluorocarbon dosing strategy on cerebral blood flow when starting partial liquid ventilation: A randomized, controlled, experimental study

Introduction: Partial liquid ventilation may benefit the lung disease in preterm neonates but intratracheal instillation of perfluorocarbon increases cerebral blood flow and may cause brain injury. We aimed to determine if the effects of perfluorocarbon administration on cerebral blood flow vary by dose-volume, rate of administration, endotracheal tube portal of entry, or closely targeting PaCO2. Methods: Forty-two dosing events (in eleven rabbits) were randomised to different dosing strategies, including a sham (i.e., placebo/control) dose of air over 20 min, 20 mL/kg of perfluorocarbon slowly over 20 min, 10 mL/kg of perfluorocarbon slowly over 20 min, 10 mL/kg of perfluorocarbon moderately fast over 10 min, 10 mL/kg of perfluorocarbon rapidly over 5 min, 10 mL/kg of perfluorocarbon slowly over 20 min via the endotracheal tube tip lumen (as opposed to the proximal end of the tube used in all other groups), or 10 mL/kg of perfluorocarbon slowly over 20 min whilst targeting a PaCO2 of 45 - 50 mmHg. Blood gases, haemodynamics, cortical cerebral blood flow and carotid flow were recorded continuously for 30 minutes from the start of each dose. Results: Carotid flow increased with 20 mL/kg perfluorocarbon and cortical cerebral blood flow was significantly more variable. Carotid and cortical cerebral blood flow increased using 10 mL/kg or 20 mL/kg with no difference between the two dose-volumes. There was no difference in cerebral blood flow by rate of administration, but carotid blood flow was more variable during slow administration. There were no differences in the increase in cerebral blood flow by portal of entry. If PaCO2 was maintained between 45 - 50 mmHg there was no increase in cerebral blood flow and there was less variable carotid flow. Conclusions: Cerebral blood flow increases with perfluorocarbon dosing. This occurs regardless of the dose-volume of perfluorocarbon. These effects were mitigated by closely targeting PaCO2.

Coalescence separation of oil water emulsion on amphiphobic fluorocarbon polymer and silica nanoparticles coated fiber-bed coalescer

Discharging untreated oily wastewater into the environment disrupts the ecological balance,which is a global problem that requires urgent solutions.Superhydrophilic and superoleophilic fibrous medium(FM)effectively separated oil–water emulsion as it was hydrophobic underwater.But its separation efficiencies(SEs)first increased to 98.9%,then dropped to 97.6%in 10 min because of oil-fouling.To tackle this problem,FM deposited with 0%–10%silica nanoparticle(NPsFMs),then coated by fluorocarbon polymer(X-[CH_(2)CH_(2)O]nCH_(2)CH_(2)O-Y-NH-COOCH_(2)C4F9)(FCNPs FMs),was used to enhance its roughness and regulate its initial wettability to improve the anti-fouling property.FCFM and FCNPs FMs were hydrophobic and oleophobic in air and oleophobic underwater.Their water contact angles,oil contact angles and oil contact angles were 115.3°–121.1°,128.8°–136.5°,and 131.6°–136.7°,respectively,meeting the requirement of 90°–140°for coalescence separation.FCNPs FM-5 had the best separation performance with a constant value of 99.8%in 10 min,while that of FCNPs FM-10 slightly decreased to 99.5%.Theoretical released droplet(TRD)diameter,calculated by the square root of the product of pore radius and fiber diameter,was used for the evaluation of coalescence performance.Analyzed by two ideal models,TRD diameter and fiber diameter showed a parabola type relationship,proving that the separation efficiency was a collaborative work of wettability,pore size and fiber diameter.Also,it explained the SEs reduction from FCNPs FM-5 to FCNPs FM-10 was revelent to the three parameters.Moreover,FCNPsFMs effectively separated emulsions stabilized by cationic surfactant CTAB(SEs:97.3%–98.4%)and anionic surfactant SDBS(SEs:91.3%–93.4%).But they had an adverse effect on nonionic surfactant Tween-80 emulsion separation(SEs:94.0%–71.76%).Emulsions made by diverse oils can be effectively separated:octane(SEs:99.4%–100%),rapeseed oil(SEs:97.3%–98.8%),and diesel(SEs:95.2%–97.0%).These findings provide new insights for designing novel materials for oil–water separation by coalescence mechanism.

Shell powder as a novel bio-filler for thermal insulation coatings

The feasibility of employing shell powder as a novel bio-filler to prepare fluorocarbon coating is demonstrated.According to the relevant Chinese standards, the thermal and mechanical properties of the shell powder-filled fluorocarbon coating were evaluated, and compared with those filled by commercial calcium carbonate. All the shell powder-filled coatings can meet the requirements stated in the relevant standards, and with decreasing the particle size of the shell powders, the performance of the thermal insulation coating is enhanced. The coating(SC3) filled by shell powders with an average particle size of 2.81 μm possesses a better thermal insulation performance than the coating(CC) filled by commercial calcium carbonate. The coating SC3 has comparable adhesive force and washing resistance with the coating CC, and in the washing resistance test, after 2000 cycles, the coating SC3 was still able to cover totally their substrates. This work demonstrates a high value-added disposal method for the aquacultural wastes.

The Effect of Relative Humidity on the Corrosion-resisting Property of Fluorocarbon Coating

The effect of relative humidity on the corrosion-resisting property of fluorocarbon coating was investigated by water vapor transmission technique and electrochemical impedance spectroscopy technique. Measuremerits were carried out on samples, which were tested in an accelerated corrosion environment for the same time （300, 500, 800 and 1000 h ）. The experimental results were obtained as follows： （i） The water absorption, coating resistance and corrosion rate of metal under the coating changed with relative humidity and aging time, the results obtained by EIS are good consistent with those by water vapor transmission technique ; （ ii ） when the subject investigated presented two time constant, the goodness of fit by EEC R （ C （ R （ CR ） ） ） was inferior to that by EEC R（ C（ R（QR） ） ）, but the error of parameters acquired from the former was smaller, by which we could analyze the experiment result quantitatively. With the appearance of diffusion layer on the metal, the difference of metal capacitance was aggravated, the error of parameters acquired from EEC R（ C（ R（ C（RW） ） ） ）was bigger than that from EEC R（ C（ R（ Q（ RW） ） ） ） .

Experimental investigation on the spread of aqueous foam over ethanol surface

The presence of ethanol has an adverse effect on foam spreading,and ethanol fire is difficult to extinguish with aqueous fire-fighting foams.Thus,it is necessary to explore the foam formulation suitable for ethanol fuels and study the spreading behavior of foam over ethanol surface.In the current work,stable foams based on hydrocarbon surfactant(SDS),fluorocarbon surfactant(FC1157),and polymers(XG)were prepared by using the compressed-air foam system.The spreading behaviors of foam on polar ethanol and non-polar heptane surface were observed and compared.Furthermore,the effects of stabilizer concentrations,foam flow rates and expansion ratios on foam spreading performance were investigated,respectively.The results indicate that aqueous SDS foam can spread on the heptane layer continuously,but it is difficult to cover the ethanol surface.The addition of XG and FC1157 can synergistically improve the spreading performance of aqueous foam over ethanol.Depending on stabilizer concentrations,there are remarkable differences in foam spreading behaviors.Besides,different foam application parameters including expansion ratios and foam flow rates significantly affect the foam spreading rate,despite the same foam formulation.The research methods and results guide the optimal design of foam formulations as well as the practical application of aqueous foam for ethanol fire extinguishment.

Evaluation of gas wettability and its effects on fluid distribution and fluid flow in porous media

The special gas wettability phenomenon of reservoir rocks has been recognized by more and more researchers.It has a significant effect on efficient development of unconventional reservoirs.First,based on the preferentially gas-covered ability and surface free energy changes,definition and evaluation methods have been established.Second,a method for altering rock wettability and its mechanisms have been studied,surface oriented phenomena of functional groups with low surface energy are the fundamental reason for gas wettability alteration of rock.Third,the effect of gas wettability on the surface energy,electrical properties and dilatability are investigated.Last,the effects of gas wettability on capillary pressure,oil/gas/water distribution and flow are investigated with capillary tubes and etchedglass network models.The gas wettability theory of reservoir rocks has been initially established,which provides theoretical support for the efficient production of unconventional reservoirs and has great significance.

Preparation of Self-crosslinked Fluorocarbon Polymer Emulsion with Core-shell Structure by the Method of Soap-free Emulsion Polymerization

Using methyl methacrylate （MMA）, butyl acrylate（BA） and hexafluorobutyl acrylate（HFBA） as main raw materials, we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free emulsion polymerization when the conception of particle design and polymer morphology was adopted. Moreover, the influence of mole ratio of BA to MAA, pH value on the oligomer was studied. And the effects of the added amount of oligomer, self-crosslinked monomer and HFBA, mass ratio of BA to MMA, reaction temperature and the initiator on the polymerization technology and the performance of the product, were investigated and optimized. The structure and performance of the fluorocarbon polymer emulsion were characterized and tested with FTIR, TEM, MFT and contact angle and water absorption of the latex film. The experimental results show that the optimal conditions for preparing fluorocarbon polymer emulsion are as follows： for preparing the oligomer, tool ratio of BA to MAA is equal to 1.0 ： 1.60, and pH value is controlled within the range of 8.0 and 9.0; for preparing fluorocarbon polymer emulsion, the added amount of oligmer[P（BA/MANa）] is 6%; mass ratio of BA to MMA is 40 ＂ 60; the added amount of self-crosslinked monomer is 2%, the added amount of HFBA is 15 %; reaction temperature is 80 ℃; the mixture of potassium persulfate and sodium bisulfite is used as the initiator. The film-forming stability of the fluorocarbon polymer emul- sion and the performance of the latex film, which is prepared with the soap-free emulsion polymerization, are better than that prepared with the conventional emulsion polymerization.

Research on Freeze Drying and High-temperature Molding in Medium-temperature Fluorocarbon Board

A research and test system for the carbon anode plate preparation technology was established to optimize the physical and chemical indicators of carbon anode plates,such as bulk density,resistivity,and compressive strength,and improve the operating cycle.In this study,a carbon plate was prepared via a combination of high-temperature molding and freeze drying using a formulation with asphalt content much lower than the industry standard.The experimental results show that the density of the carbon plate is increased by 0.02-0.04 g/cm^(3) by improving the drying method.The carbon plate prepared in the laboratory has a bulk density of 1.814 g/cm^(3),resistivity of 29.8μΩ·m,and compressive strength of 89.27 MPa.The bulk density,room-temperature resistivity,compressive strength,graphitization,and other key indices of the carbon plates made in the laboratory and those procured from a factory in Shanxi,Datong,were tested.Additionally,the specimens were analyzed using thermogravimetry-differential scanning calorimetry,scanning electron microscopy,and X-ray fluorescence.The laboratory-made carbon plates were superior to the factory specimens in terms of all the indicators tested.The process in this study improves the performance of the carbon anode plate and is used to provide technical support for electrolytic fluorine production in enterprises.The carbon plates prepared in the laboratory fully meet the process requirements of a medium-temperature electrolytic fluorine production line,which indicates the possibility of its use in the stable production of fluorine gas.

Characterization of Crystalline Nanoparticles/Nanorods Synthesized by Atmospheric Plasma Enhanced Chemical Vapor Deposition of Perfluorohexane

A mass of nanoparticles/nanorods were formed on a simultaneously deposited gran- ular film by plasma enhanced chemical vapor deposition （PECVD） of perfluorohexane at atmo- spheric pressure without any catalysts or templates. Scanning electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS） were used to characterize the morphology and the chem- ical compositions of nanoparticles. The average size of particles is about 100 nm and the length of synthesized nanorods is between 1 μm and 2.5/tm. The analyses of transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, selected area electron diffraction（SAED） and X-ray diffraction （XRD） reveals that the nanoparticles and nanorods are crystalline.

Effect of Low-frequency Power on F, CF_2 Relative Density and F/CF_2 Ratio in Fluorocarbon Dual-Frequency Plasmas

Effect of low-frequency power on F, CF2 relative density and F/CF2 ratio, in C2F6, C4F8 and CHF3 dual-frequency capacitively couple discharge driven by the power of 13.56 MHz/2 MHz, was investigated by using optical emission spectroscopy. High F, CF2 relative density and high F/CF2 ratio were obtained in a CHF3 plasma. But for C2F6 and C4Fs plasmas, the F, CF2 relative density and F/CF2 ratio all decreased significantly due to the difference in both reactive paths and reactive energy. The increase of LF power caused simultaneous increase of F and CF2 radical relative densities in C4Fs and CHF3 plasmas, but led to increase of F with the decrease in CF2 relative densities in C2F6 plasma due to the increase of lower energy electrons and the decrease of higher energy electrons in electron energy distribution function （EEDF）.

Growth of Fluorocarbon Films by Low-Pressure Dielectric Barrier Discharge

Plasma polymerized fluorocarbon （FC） films have been deposited on silicon substrates from dielectric barrier discharge （DBD） plasma of C4Fs at room temperature under a pressure of 25～125 Pa. The effects of the discharge pressure and frequency of power supply on the films have been systematically investigated. FC films with a less cross linked structure may be formed at a relatively high pressure. Increase in the frequency of power supply leads to a significant increase in the deposition rate. Static contact angle measurements show that deposited FC films have a stable, hydrophobic surface property. All deposited films show smooth surfaces with an atomic surface roughness. The relationship between plasma parameters and the properties of the deposited FC films are discussed.

Fluorinated Surfactants and Fluorinated Polymer Materials(Ⅱ):Environmental and Safety Issues

The environmental and safety issues of perfluorooctane sulfonyl fluoride/perfluorooctane sulfonic acid/ perfluorooctane sulfonates (PFOS) were introduced in detail by summarizing several published reviews, including their production, occurrence and emission in environment, exposure and intake to human being, supervision and emission reduction, long-distance transport, bioaccumulation and excretion, degradation and toxicity. Opinion with respect to safety issues of PFOS was also proposed in view of surfactant working field in order to upgrade their application value. The overreaction in the current state for the fear of “fluorine” was concerned. For fire-fighting foams, the issue of “safety” needs to be critically weighed.

Interaction of Polyelectrolyte with Fluorocarbon Surfactant in Aqueous Solution

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STUDIES ON THE PERMEABILITY OF P VC/EBBA OVERLAPPED ULTRATHIN COMPOSITE MEMBRANES MODIFIED BY PLASMA-POLYMERIZATION WITH FLUOROCARBON MONOMERS

The PVC/EBBA ultrathin composite membranes with thickness of about 100 nm were prepared by spreading the solution on water surface. The overlapped composite membrane showed a characteristic aggregation structure in which the polymer matrix exists as a three-dimensional spongy network and the liquid crystal domains werc observed. Tne surface modification for the overlapped membranes was carried out by means of plasma-polymerization with the monomers of fluorocarbon compounds. Both Arrhenius plots of permeability coefficients for oxygen ((?)_O_2) in the membrane samples before and after modification showed significant increase in the vicinity of the T_(KN) of EBBA.

Oxygen Isotope Fractionation of Common RE Fluorocarbonate

Fluorocarbonate is one of the most important RE minerals in the earth With the increment model developed by Zheng, oxygen isotope fractionation of RE fluorocarbonates is discussed and the 18 O enrichment order is obtained as follows: bastnaesite>cordylite>Ca 0 5 BaCe 2(CO 3) 4F>baiyuneboite>huangheite>cebaite Combining with the calculated equation, the oxygen isotopic compositions in RE fluorocarbonate from Bayan Obo ore deposit is discussed, and a better accordance of 18 O enrichment order with actual data on ore forming temperature with the ore deposit geology are found Because Ba RE fluorocarbonate could be considered as a stacking of CeCO 3F and BaCO 3 layers in the direction c , oxygen isotope fractionation in this stacking is discussed, and I in zhonghuacerite and cordylite is predicted with this model

Domain Structure in Calcium Cerium Fluorocarbonate Minerals, Mianning County, Sichuan Province, China

The domain structures in calcium-cerium fluorocarbonate mineral series from a rare earth mineral deposit within an aegirine alkali granite massif in Mianning County, Sichuan Province, China, were studied by means of transmission electron microscopy. Many categories of domain structures in this mineral series were observed and investigated, including the microtwin domains of parisite-6R(2) and B2S-6R, the antiphase domains of B2S-2H. The results show that the antiphase domains which are faults along crystal plane (0001) are formed by the displacement of crystal lattice in c * direction and the displacement is 0.471 nm. A new polytype (B4S2-3R) of regular mixed-layer structure with B4S2 type is found in the domain region of mixed-layer structure.

Photoluminescence of silicone oil treated by fluorocarbon plasma

We investigated photoluminescence characteristics of silicone oils treated by C2F6 and CHF3 plasma. The silicone oil treated by the C2F6 plasma emitted a white light mainly composed of 415 nm, 469 nm, and 554 nm emissions, while that treated by the CHF3 plasma emitted a pink light （415 nm）. Fourier transformed infrared spectroscopy and Raman spectroscopy studies showed that the photoluminescence was correlated with the Si-C bond, the carbon-related defects and the oxygen vacancies. It was suggested that the light emitting at 554 nm was related to the Si-C bond and the carbon-related defects, while the pink emission at 415 nm was related to the oxygen vacancies.

C_2F_6 /O_2 /Ar Plasma Chemistry of 60 MHz/2 MHz Dual-Frequency Discharge and Its Effect on Etching of SiCOH Low-k Film

This work investigated C2F6/O2/Ar plasma chemistry and its effect on the etching characteristics of SiCOH low-k dielectrics in 60 MHz/2 MHz dual-frequency capacitively coupled discharge. For the C2F6/Ar plasma, the increase in the low-frequency （LF） power led to an increased ion impact, prompting the dissociation of C2F6 with higher reaction energy. As a result, fluorocarbon radicals with a high F/C ratio decreased. The increase in the discharge pressure led to a decrease in the electron temperature, resulting in the decrease of C2F6 dissociation. For the C2F6/O2/Ar plasma, the increase in the LF power prompted the reaction between 02 and C2F6, resulting in the elimination of CF3 and CF2 radicals, and the production of an F-rich plasma environment. The F-rich plasma improved the etching characteristics of SiCOH low-k films, leading to a high etching rate and a smooth etched surface.