Jun.2014,Vol.43,No.3
CHEMICAL ENGINEERING OF OIL & GAS
ABSTRACTS
Review and suggestions on reducing SO2 emission concentration of Claus tail gas treatment unit
Chen Gengliang, Li Jin(Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company，Chengdu 610213, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp217-222,2014（ISSN 1007-3426, IN CHINESE）
Abstract: For the technical plan of reducing SO2 concentration from 960 mg/m3 to below 500 mg/m3 in Claus unit tail gas, it was pointed out that decreasing lean solution temperature and H2S concentration in selective absorber of SCOT unit, the total sulfur recovery rate can be effectively increased to more than 99.9%. If formulated solvents are used in addition, the efficiency of selective absorption and total sulfur recovery rate could be further improved. Currently industrial data showed that Cansolv method belongs to oxidation-absorption technology of tail gas treatment and the total sulfur recovery is lower than that of standard-type SCOT units. Therefore, the adoption of Cansolv technology for treating the tail gas of Claus unit should be carefully reviewed.
Key words: Claus unit, tail gas treatment, SCOT technology, Cansolv technology, SO2 emission concentration
Surface chemical property study of TiO2 based sulfur recovery catalyst
Wen Chongrong1,2,3， Zhu Ronghai1,2,3， Yu Changchun4（1. Research Institute of Natural Gas Technology，PetroChina Southwest Oil & Gasfield Company， Chengdu 610213， Sichuan， China； 2. National Energy R&D Center of High Sulfur
Gas Exploitation，Chengdu 610213，Sichuan，China；3. High Sulfur Gas Exploitation Pilot Test Center， CNPC， Chengdu 610213， Sichuan， China； 4.China University of Petroleum-Beijing， Beijing 102249， China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp223-227,2014（ISSN 1007-3426, IN CHINESE）
Abstract: With the rapid development of oil refining industry and natural gas industry, sulfur dioxide emission standard would be increasingly strict. Sulfur recovery and tail gas treatment are the main process for the treatment of sour gas containing hydrogen sulfide from the processing of petroleum and natural gas purification process. TiO2 based sulfur recovery catalyst has been applied widely. By the characterization of XPS, XRD, TEM, FT-IR, CO2-TPD, NH3-TPD and pyridine IR, the results showed that the catalysts were composed of nano-sized anatase phase titanium dioxide with weak and strong basic position.
Key words: TiO2 based catalyst, sulfur recovery, surface property
Researsh on deep desulfurization and decarbonization technology of LNG feed gas
Zhou Yongyang1,2,3,Huang Liming1,2,3,He Jinlong1,2,3,Peng Xiujun1,2,3(1．Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company，Chengdu 610213, Sichuan, China; 2. National Energy R&D Center of High Sulfur Gas Exploitation， Chengdu 610213, Sichuan, China; 3. High Sulfur Gas Exploitation Pilot Test Center， CNPC， Chengdu 610213， Sichuan， China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp228-233,2014（ISSN 1007-3426, IN CHINESE）
Abstract: It is necessary to cool natural gas to about -162 ℃ during the liquefaction process. In order to avoid freezing plugging of the equipment and pipelines during the cryogenic liquefaction process, the acidic components of natural gas should be removed deeply. The key process technology of feed gas pretreatment unit for LNG plant, which includes desulfurization and decarbonization is mainly introduced. The characteristics and technical advantages of CT8-23 activated MDEA solvent and CT8-25 solvent, which can deeply remove the H2S, CO2 and organic sulfur, are described. Both of the solvents have been developed independently by Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company. Compared to similar foreign solvents Sulfinol-D, the results show that CT8-25 solvent can removal H2S，CO2 deeply to reach the requirements. When the absorption pressure is 2 MPa, the plate number of absorber is 13, and the removal rate of organic sulfur is 28% higher than Sulfinol-D.
Key words: LNG, desulfurization, decarbonization, organic sulfur removal, CT8-23, CT8-25
Reaction performance of nitrogen removal adsorption from the coking wax oil with activation resin
Sun Jingjun， Xiu Penghao， Cong Riming， Dong Hao，Wang Cong，Wang Lei， Liu Dan（School of Petrochemical Engineering，Liaoning Shihua University，
Fushun 113001， Liaoning， China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp234-240,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Under laboratory conditions，nitrogen adsorption from the coking wax oil was studied respectively by D72 and D001-CC cationic activation resins as adsorbents in a continuous fixed bed reactor. Micro reaction system of fluid catalytic cracking unit was used to study the catalytic cracking reaction performance of coking wax oil after denitrification. Adsorption properties of two kinds of activation resin were compared by studing the adsorption breakthrough curve in the fixed bed, the dynamic adsorption properties of alkaline nitrogen compounds in the coking wax oil and the affect of the adsorption temperature on the removal rate of basic nitrogen compounds. Catalytic cracking performances of coking wax oil before and after denitrification were finally compared with catalytic cracking experiments. Results of experiments showed that the optimum adsorption temperature of D001-CC activation resin was 70 ℃，the adsorption capacity was saturated 6 hours later，and the saturated adsorption capacity is 19.35 mg/g. The optimum adsorption temperature of D72 activation resin was 60 ℃，the adsorption capacity was saturated 5 hours later，and the saturated adsorption capacity was 7.75 mg/g. The degree of catalytic cracking of coking wax oil deepened and the conversion rate improved after dealing with the resin denitrification. When the reaction temperature was 400 ℃， the conversion rate of coking wax oil without denitrification was 44%. The conversion rate of coking wax oil reached 81.5% after 30 minutes’ adsorption denitrification treatment. The influences of alkaline nitrogen content on catalyst activity were more sensitive at higher reaction temperature. The more substantially decrease of alkaline nitrogen content in the coking wax oil, the more significantly increases of catalytic cracking conversion rates.
Key words: coking wax oil， basic nitrogen compounds， cationic activation resin， fixed bed， catalytic cracking
Structure parameters optimization of the inclined oil-water separator based on orthogonal design
Huang Kun1, Wang Yijia1, Li Xinzhan2, Lyu You1, He Huijuan1, Liu Zilin1（1. School of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500,
Sichuan, China；2. Gan-Shan Management Office, West-East Gas Pipeline Company,
PetroChina, Xi’an 710016, Shaanxi, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp241-245,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The inclined oil-water separator is a new efficient oil-water separation equipment and the structure of which is designed preliminarily. In order to improve the oil-water separating efficiency, orthogonal design is introduced to optimize the structural parameters. An orthogonal scheme with 8 factors and 5 levels is designed to get 50 different structure models. Fluent 12.0 software was used to simulate the 50 models and 25 schemes of them were selected for visual analysis, as a result, the scheme A was determined as an optimal scheme. By the range analysis of numerical data and the influence analysis of structure parameters on the impact of oil-water separation efficiency, the highest levels of the average oil-water separation efficiency were combined to get an optimal plan B. After comparing A with B, it showed clearly that optimal parameters of the inclined oil-water separator was plan B. By simulating flow field with the same method, it was found that the optimized separation efficiency increased by 4.972%, which showed that orthogonal design in optimizing structure parameters of the separators had some practical significance.
Key words: inclined oil-water separator, structure parameters, orthogonal design, numerical simulation, separation efficiency
Process optimization for preparing biodiesel from plam oil with CaO/MgO/γ-Al2O3 solid base catalyst
Lu Chuanzhu1, Wang Jian1, Li Zhichao1, Li Huipeng1, Zhao Hua1，Zhang Deqing2（1. School of Petrochemical Engineering, College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Fushun 113001, Liaoning, China；2. Liaohe Oilfield Economic and Trade Realty Corporation, Panjin 124010, Liaoning, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp246-249,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Supported CaO/MgO/γ-Al2O3 solid base catalysts were prepared by using impregnation method. The optimal preparation conditions of catalyst which has good catalytic effect were defined as follows：the molar ratio of Ca to Mg is 4∶1, calcinated at 750 ℃ for 12 h, and mass ratio of CaO to γ-Al2O3 is 18%. It was used to catalyze methyl esterification of palm oil. The results showed that the highest yield was 95.3% when the molar ratio of methanol to oil was 7∶1 with addition 3.5% (wt%)CaO/MgO/γ-Al2O3 of oil and reacted at 60 ℃ for 2 h.
Key words: biodiesel, solid base catalyst, palm oil, transesterification
Application of electric heater reheat technology on sulfur recovery unit
Wang Xiaoqiang1, Qiu Bin1, Zhao Liujian1, Gao Jianwen1, Chen Liang1, Tian Mengwen1, Huang Xuan2（1. Chongqing Natural Gas Purification Plant General，PetroChina Southwest Oil & Gasfield Company，Chongqing 401433, China; 2. Materials Company, PetroChina Southwest Oil & Gasfield Company，Chengdu 610200, Sichuan, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp250-253,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Aiming at current situations and characteristics of the sulfur recovery unit in Qijiang Branch, the process gas reheating methods were determined. The advantages and disadvantages of five kinds of reheat methods technology were analyzed including high temperature mixed, reheating furnaces, steam heating, gas-gas heat exchanger and electric heater. The electric heater was finally determined because of the advantage of convenient energy service, compact structure, automatic temperature control, simple operation and no pollution. The Results showed that system temperature was in normal range and sulfur recovery unit ran properly when the sulfur recovery unit operated at low load. Meanwhile, the common problems and abnormal situations of electric heater were analyzed and summarized.
Key words: sulfur recovery, process gas, electric heater, reheat
Design of liquefied natural gas and natural gas properties calculation software
Tian Shizhang1, Chen Shuai1,Yang Bo2(1.PetroChina Dalian Liquefied Natural Gas Company Limited,Dalian 116600,Liaoning, China; 2. Guangdong Natural Gas Co., Ltd, CNOOC, Zhuhai 519015, Guangdong, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp254-261,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The production and operation of LNG terminal are based on liquefied natural gas (LNG) and natural gas (NG) properties calculation. Although there are many foreign commercial softwares which can calculate the properties, most of them are expensive and complex. Therefore, BWRS equation as the theoretical basis, the properties calculation software is designed based on the Forcecontrol V7.0 software platform which is simple and can meet the needs of LNG Terminal. By comparing the data of the actual operation in Dalian LNG Terminal, calculated data by Aspen Plus and by this software, relative errors about some typical properties have been received. Meanwhile, the reliability of the calculation has been verified with some examples. Results show that the software can provide fairly accurate calculation results of LNG and NG properties and can well meet the properties calculation needs of LNG Terminal.
Key words: liquefied natural gas, natural gas, LNG Terminal, properties calculation, BWRS equation, Forcecontrol V7.0, calculation software
Influence of feed gas components change on LNG plant and countermeasures
Li Junfang1, Zhang Ruichun1, Xia Gongke2, Liu Shengpeng1,Gan Zhuofan1, Xie Zhonghai1(1.Chengdu Natural Gas Chemical Works, PetroChina Southwest Oil ﹠ Gasfield Company, Chengdu 610213, Sichuan, China；2.CNGC Guang’an Natural Gas Co.,Ltd, Guang’an 638000, Sichuan,China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp262-265,2014（ISSN 1007-3426, IN CHINESE）
Abstract: This paper introduced the operation problems of Guang’an LNG plant due to the components change of feed gas, which included heavy hydrocarbon blocking at low temperature and ethane adaptability. The phenomenon and reason of the problem were analyzed, and the solution and application effect were discussed. After adjusting the process parameters and adding activated carbon to remove heavy hydrocarbon, the plant ran steady. The components of the feed gas has great effect on the operation of LNG plant. Therefore, the analysis and forecast of feed gas components change are very important to new LNG plant.
Key words: components of natural gas, heavy hydrocarbon blocked due to low temperature, ethane adaptability
Analysis of natural gas pipeline network design features of Liaohe Oilfield
Zhao Qilong(China Liaohe Petroleum Engineering Company Limited，Panjin 124010,Liaoning,China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp266-270,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The suitable design of natural gas pipeline network in Liaohe oilfield region was studied. Based on the gas consumption characteristics of each oil production plant in Liaohe Oilfield, the pipeline model was established combining with the actual project. The model was used to simulate the pipeline network layout, and study the parameter changes of flow, temperature and pressure. According to the geographical features, the suitable design of the natural gas pipeline network in this region was identified. The results showed that the self-balancing pressure regulation system could solve the problems caused by unbalancing gas consumption and brought by the oil production plant in Liaohe Oilfield. The small directional drilling crossing mode could be used to solve problems of high ground water, more rivers and ditches. The multiple pipeline back-dragging technology in a same hole was used in Liaohe Oilfield for the first time and got good effect.
Key words: natural gas pipeline network, self-balancing, small directional drilling, multiple pipeline back-dragging in a same hole
Process design and parameter optimization of Yibin Data light hydrocarbons recycle project
Zhu Lin(Tianjin Zhenjin Engineering Design Consulting Co., Ltd,Tianjin 300384, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp271-274,
2014（ISSN 1007-3426, IN CHINESE）
Abstract: Yibin Data light hydrocarbons recycle project deals with gas from shallow oil and gas field to recycle light hydrocarbons, liquefied petroleum gas (LPG) and produce liquefied natural gas (LNG) in Data, Yibin. According to the gas components of oil and gas field and characteristics of the project, the direct heat exchange (DHX) technology is adopted to recycle light hydrocarbons and single cycle compound throttling mixed refrigerant-cycle refrigeration (SMCR) is used for natural gas liquefaction. The output pressure of natural gas pipeline network had been set, so the operating parameters of the process need to be optimized. HYSYS was applied to simulate, optimize and calculate the recovery of light hydrocarbons and process of LNG liquefaction. This article analyzed DHX process under different temperatures to optimize operating parameters on the basis of energy consumption, recovery rate and economic benefits.
Key words: light hydrocarbons recycle, direct heat exchange (DHX), recovery rate, energy consumption, Yibin Data
Selection and evaluation of low alloy steel for sour service
Yang Jianqiang, Zhang Zhonghua, Zhang Chunxia, Guo Jinbao（Baoshan Iron & Steel Co., Ltd，Shanghai 201900, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp275-278,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Main failure modes and application limit of low alloy steel oil country tubular goods (OCTG) for sour service by relevant international standard were analyzed in this paper. The influences of metallurgical and environmental factors upon sulfide stress cracking （SSC） resistance property were discussed, and selection of SSC evaluation methods were described from the point of stress analysis and fitting for service.
Key words: low alloy steel, sulfur resistance, oil country tubular goods (OCTG), material selection, SSC
Technology research of the recycled low molecular guar gum fracturing fluid
Xiong Ying, Liu Youquan, Shi Xiaosong, Zhang Yongguo, Wu Wengang, Huang Chenzhi, Chen Nan(Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp278-283,2014（ISSN 1007-3426, IN CHINESE）
Abstract: To solve the problems of water shortage in fracturing operation and fracturing outlet liquid handling difficulty, the borate dissociation equilibrium principle is controlled by pH value to change the crosslinked state of guar gum fracturing fluid for the degradability of gel breaking under acidic condition. The molecular structure of guar gum is not damaged, so it can be crosslinked again. This paper used the biodegradation technology to degrade guar gum, and controlled the molecular weight of the guar gum by controlling the degradation conditions to control the degree of degradation of guar gum, eventually a low molecular crosslinked guar gum have been developed with molecular weight from 30×104 to 50×104 under the condition of borate. The viscosity of aqueous solution of the low molecular guar gum was low，and the water insoluble content was less than or equal to 4%. Taking a solid acid as a capsule core, a polymer being gradually dissolved in the water as the capsule dressing, a capsule breaker have been prepared using the method of air suspension film. The capsule breaker is not acidic on the ground for ensuring the fracturing fluid to be crosslinked well, and under formation temperature and pressure conditions the capsule breaker can gradually release the solid acid for the fracturing fluid degradability gel breaking. Taking the low molecular guar gum as the thickening agent, the capsule breaker parceling solid acid as the breaker, a recycled low molecular guar gum fracturing fluid has been developed. The fracturing fluid has been widely used in Sichuan Xu Jiahe reservoir reconstruction, and a lot of fracturing outlet liquids have been recycled. The effect of energy conservation and emissions reduction is remarkable.
Key words: fracturing fluid, recycling, guar gum, low molecular, fracturing outlet liquid
Characteristics of crude oil wax by simulating CO2 flooding process of Yanchang Oilfield
Yin Zhifu, Li Jiandong, Wei Yanlin, Fang Xiaojun, Liu Jie(Research Institute of Shaanxi Yanchang Petroleum (Group) Co., Ltd, Xi’an 710075, Shaanxi, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp284-286,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The wax deposition tendency and its characteristics in crude oil produce at a CO2 flooding oilfield block were investigated under various CO2 partial pressures. The wax deposition rate, wax deposition percentage and wax content were calculated. The characteristics of wax precipitation point curves were also analyzed. The results indicated that both wax deposition rate and wax deposition percentage of crude oil increased with CO2 partial pressure increasing, while wax content decrease meant wax deposition more significantly. In addition, wax precipitation point of crude oil by CO2-processed moved in the lower temperature direction, and the wax content was lower than that of unprocessed crude oil.
Key words: CO2 flooding, wax deposition, wax deposition rate, wax precipitation point
Influence of injection parameter on microbial enhanced oil recovery
Lei Guanglun1, Cheng Mingming1, Gao Xuemei1, Liu Jianying2, Yang Jian2(1. China University of Petroleum (East China), Qingdao 266580, Shandong, China;2. PetroChina Changqing Oilfield Company, Yan’an 716000, Shaanxi, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp287-291,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Superiority strains G1-1 was obtained from the sludge samples collected from the Triassic Yanchang 6 reservoir and the oil-displacement capacity was tested. The impact of injection parameter on microbial enhanced oil recovery was researched. Through the artificial core flooding experiments, the best microbial injection slug was optimized to be 0.3-0.45 PV, and the best injection speed was water flooding speed in field trial of 0.48 m/d. The effect of section increasing oil by plug injection was the best, which could improve oil recovery up to 15.24%. The experiment results show that the selected strains have good compatibility with reservoir and obvious stabilizing oil production by water control effect.
Key words: microbial, recovery factor, injection parameter, displacement ability, artificial core flooding experiment
Effect of pH value on foaming properties of oleate and recirculating utilization mechanism of foam
Zhu Li1, Wan Liping1, Gu Siman1, Shu Xiaobo2, Zhai Lituan3, Tao Jie4(1.State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China; 2. Drilling & Production Engineering Technology Research Institute of Chuanqing Drilling Engineering Co., Ltd., CNPC, Guanghan 618300, Sichuan, China; 3. PetroChinaTarim Oilfield Company, Korla 841000, Xinjiang, China; 4. CNOOC China Limited QHD32-6 Operating Company, Tianjin 300452, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp292-296,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The acid and alkali circulation utilization of foam can be realize due to the exist of pH-sensitivity carboxyl groups in oleate. With methods of Warning-blender, acid-base titration test, surface tension and interfacial tension test and microscopic analysis, etc., the effects of pH values change on aqueous solution properties of oleate, ionization degree of carboxyl group of oleate, and foaming properties of oleate were analyzed. Meanwhile, six foam circulation experiments have been carried out, and defoaming mechanism was discussed through explanation of microscopic phenomena, spreading and bridging mechanisms. The results show that carboxyl group of oleate can easily lose or receive protons to realize the reversible interconversions between active and inactive, further to realize circulation utilization of foam. Also, the defoaming mechanism analysis suggests that the invasion of hydrogen ions can lead to form water insoluble oleic acid of foam structure of oleate, and into the foam liquid films structure, facilitate liquid films rupture through spreading or bridging action, so as to achieve the effect of defoaming.
Key words: pH value， oleate， foam circulation， defoaming mechanism
Impact of drilling fluid additives on performance of the cement slurry by single-factor
Li Ming1, Wang Wei1, Zheng Youzhi2, Cheng Xiaowei1, Dai Bin3, Guo Xiaoyang1(1.State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Southwest Petroleum University, Chengdu 610500, Sichuan, China; 2. Gas Production Engineering Research Institute, Petrochina Southwest Oil＆Gasfield Company, Guanghan 618300, Sichuan, China; 3. Tarim Petroleum Exploration and Development Headquarte, Kuerl 841000, Xinjiang, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp297-301,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The compatibility of drilling fluid and cement slurry is poor, and pollution will occurs as long as they contact, namely liquidity deterioration of mix slurry fluid, shortage of slurry thickening time and decrease of the cement ring strength. This paper studied the impact of drilling fluid additives used in Sichuan and Chongqing on the performance of the cement slurry by single-factor. The composition of additives was characterized by infrared spectroscopy, and the structure of cement stone was analyzed by environmental scanning electron microscope. The results show that biological tackifier and polyacrylamide potassium( KPAM) can make the slurry thicken quickly；SMT, SMP-1 and JN-A will shorten the thickening time, while the effect is small within the dosage of less than 1%. The rest additives have less affect within a certain range. Then the pollution reason was analyzed. One of the important reasons is that some additives participate in cement hydration, and affect the process of slurry formation. Polymer macromolecular chains curled and adsorption bridging will make the cement slurry flocculate. The proposal of pollution mechanism provides a theoretical basis for reasonable selection of drilling fluid additives，and can reduce the pollution of drilling fluid and cement slurry.
Key words: drilling fluid, cement slurry, pollution, mechanism, cementing
Preparation and evaluation of environment friendly water-based drilling fluid additive by persimmon peel
Zhang Jianjia1, Zhang Jie1, Chen Gang1, Pu Lin2(1. College of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, Shaanxi, China; 2.Chengdu Lanjing Sci. Tech. Co., Ltd, Chengdu 610055, sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp302-307,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The powder of persimmon peel was used as water-based drilling fluid addictive, and the performance of it was evaluated. The results showed that persimmon peel performed a great effect of reducing fluid loss, and with the treatment temperature increasing, apparent viscosity and plastic viscosity was firstly increased, then reduced, and finally increased, the filtration reduction weakened and invalided above 150 ℃. The results of linear bentonite swelling experiment and mud ball experiment presented that water extract of persimmon peel can inhibit hydration and swelling of clay along with the concentration, excelled to that of 4%(wt) KCl solution. The results of compatibility with common drilling fluid additives showed that the viscosity and filtration reduction increase along with the treatment temperature increasing companying with modified starch, while the compatibility with polyacrylamide is poor, especially, the viscosity drops suddenly (from 30.0 mPa·s to 4.0 mPa·s) at 120 ℃ and filtration reduction is invalid.
Key words: persimmon peel, water-based drilling fluid, additive, filtration reduction
Velvet vesicles formation of composite surfactant system and its stability study
Yi Aiwen1，Xu Liang2，Yang Yongzhao1, Cao Yuecheng1, Gao Jiangjiang1（1. Xingzichuan Oil Production Plant of Yanchang Oil Field Co.，Ltd，Yan’an 717400,
Shaanxi, China; 2. Development Department of Yanchang Oil Field Co.，Ltd，Yan’an 716000, Shaanxi, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp308-312,2014（ISSN 1007-3426, IN CHINESE）
Abstract: This thesis mainly studies the composite stabilizer of a series of anionic/cationic surfactant, and selects sodium dodecyl benzene sulfonate（SDBS）and tetradecyl trimethyl ammonium chloride（TTAC）as velvet pouch formation system. Adding polymer into the system under the conditions that the total concentration of surfactant is 0.02 mol/L and V（SDBS）∶V（TTAC）=7∶3, the viscosity of the system increases, surface tension reduces, friction between the molecules increases, binding force of the surface molecules decreases, and all of that make the system stabilization. Analysis of the particle size shows that the particle size becomes larger and distributed evenly after adding polyving akohol(PVA) of 0.2% mass fraction into the velvet pouch system. When studying the stability of the system, velvet pouch system would be damaged by CaCl2 and MgCl2, while the stability would become better by adding PVA, and could not be easily damaged by salt.
Key words: fvelvet vesicles, particle size, surface tension,surfactant
Discussion on quality requirements of natural gas entering long distance pipeline in multiple gas sources environment
Cai Li1,2, Pan Chunfeng1,2, Li Yan1,2, Luo Qin1,2, Tang Meng1,2(1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, Sichuan , China; 2. Key Laboratory of Natural Gas Quality and Energy Measurement, CNPC, Chengdu 610213, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp313-317,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Under multiple gas sources environment, the quality of natural gas and substituted natural gas is quite complex. In order to ensure the safety of long distance pipeline and the natural gas metering accuracy, the gas quality of conventional， unconventional natural gas and substituted natural gas is discussed. The gas quality control demanded in multiple gas sources environment is summarized. In order to formulate the national standard of quality requirements for all kinds of gas entering long-distance transmission pipe networks, the control limits were discussed to find out the limits which including the concentration of total sulfur, hydrogen sulfide, carbon dioxide, carbon monoxide, hydrogen, oxygen, particles, and water content/water dew point. These parameters are fully discussed.
Key words: multiple gas sources, conventional natural gas, unconventional natural, gas quality requirement
Comparison and analysis for quality index of coal-based substitute natural gas
Xing Chengzhi1, Hu Zhaoji2, Hao Peng3, Zhu Fengdong1(1.CNOOC New Energy Investment Co., Ltd, Huhhot 010010, Inner Mongolia, China;2. School of Environmental Science & Engineering, Nanchang University, Nanchang 330029, Jiangxi, China； 3.Yili Xintian Coal Chemical Co., Ltd, Xinjiang 835000,China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp318-321,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Based on the quality characteristic of current coal-based substitute natural gas (SNG), the composition, high calorific value,interchangeability and water dew point for coal-based SNG are presented. The comparison between coal-based SNG and conventional natural gas is completed comprehensively, and essential property and fuel gas quality of coal-based SNG are pointed out. It is illustrated that there is no constrained problem for coal-based SNG incorporation and interchange application with traditional natural gas, and the coal-based coal-based SNG is clean fuel gas in high quality as a beneficial and necessary supplementary for conventional natural gas. This paper provides references for coal-based SNG promotion and application as a new kind of clean energy resource, and coal-based SNG quality standard establishment.
Key words: coal-based substitute natural gas, methane, quality index, calorific value, interchangeability, water dew point
Determination of sulfur compounds in high sour natural gas by gas chromatography
Wang Hongli, Chi Yongjie, Wan Ying, Li Xiaohong, Han Hui(Research Institute of Natural Gas Technology, PetroChina Southwest Oil ＆ Gasfield Company, Chengdu 610213, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp322-325,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The method was established for determination of sulfur compounds in high sour natural gas by gas chromatography with sulfur chemiluminescent detector. The pollution to detector and interference from high concentration H2S has been solved by using micro flow controller. A fast and economical method has been established to detect several sulfides in sulfur-bearing natural gas with only one standard material. The qualitative analysis of sulfides was performed according to retention time of standard material and the quantitative analysis was performed on the basis of External Standard Method. The linear relationship between sulfur content and chromatographic peak area is obvious with this method for testing high sulfur natural gas sample and the correlation coefficient r was 0.999 7. The relative standard deviation for sulfides under the concentration of 2 mg/m3 was less than 6.1%, and that of the sample with the concentration above 2 mg/m3 was less than 2.2%. The methods can completely meet the needs to analyze the high sulfur natural gas.
Key words:gas chromatography，micro flow controller，sulfur
chemiluminescence detector, high sulfur natural gas，analysis, sulfur compounds
Removal of silicon and turbidity from oil refinery effluent by chemical coagulation progress
Du Wenting1, Wang Bing1, Liu Guangquan2, Ren Wen2, Liu Peng2, Ren Hongyang1(1.School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, Sichuan, China; 2. CNPC Research Institute of Safety & Environment Technology, Beijing 102206,China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp326-330,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The oil refinery effluent was dealt with biochemical treatment taking A2/O as a core, and its quality could reach the comprehensive discharge standard of effluent. The effluent could be recycled by the low pressure multi-effect evaporation system using the low temperature heat of oil refinery, and it was the new measure of energy saving and emission reduction. The silicon and turbidity were the main parameters of evaporation process. The removal effect of silicon and turbidity by softening with lime, magnesium salt precipitation and precipitation by combination coagulant of molysite and aluminium salt were researched. The results indicated that: when the dosage of Ca(OH)2 was 500 mg/L, the removal rate of silicon and turbidity were 79.2% and 4.2%，respectively, and when the dosage of MgCl2 was 400 mg/L at the pH value of 10, the removal rate of silicon and turbidity were 91.6% and 74.4% ,respectively. The requirement of low temperature multi-effect evaporation system could be achieved, when the dosage of Fe(Ⅱ/Ⅲ)Al combination coagulant was 400 mg/L and the removal rate of silicon and turbidity were 91.9% and 90.4%，respectively. The residual silicon content and turbidity were 17.93 mg/L and 3 NTU.
Key words: oil refinery effluent, low temperature multi-effect evaporation, coagulation, silicon and turbidity removal
Energy efficiency benchmarking methods in natural gas purification business
Gou Xiaojing1, Huang Zhaoqi2, Gong Yiran2, Chen Shiming2, Wang Lingjun2(1.Quality, Safety and Environmental Protection Department, PetroChina Southwest Oil & Gasfield Company，Chengdu 610051, China；2. Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfield Company, Chongqing 401259, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp331-334,2014（ISSN 1007-3426, IN CHINESE）
Abstract: According to the requirements of PetroChina Exploration and Production Branch, Southwest Oil & Gasfield Company carried out energy efficiency benchmarking for gas purification business. The method of “subdivision unit, and ratings contrast” was used to basically overcome the differences between purification devices, and eliminate the impact level of non-comparable factors, which provides a feasible idea for energy efficiency benchmarking of oil and gas field upstream business. The technology difficulties and solution ideas of energy efficiency benchmarking in gas purification business were summarized.
Key words: natural gas purification, energy efficiency benchmarking, method, energy saving and consumption reducing
Research on spontaneous combustion risk of the iron-sulfur compounds in Bohai Oil-gas Field
Huang Gang, Tu Qiang, Hao Xiaopeng, Han Tao, Xu Meng（CNOOC Safety Technology Service Co., Ltd, Tianjin 300456,China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp335-338,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The iron-sulfur compounds are produced easily in the process of oil and gas production by active sulfur and inactive sulfur with the iron. When exposed to air after a long period, it will result in spontaneous combustion, fire, explosion and other accidents. This paper describes the mechanism of iron-sulfur compounds formation and spontaneous combustion. The energy spectrum, X-ray diffraction and self thermal characteristic analysis are conducted for field samples. The conclusion shows that spontaneous combustion potential hazards of iron-sulfur compounds in Bohai oil and gas field are existed.
Key words: iron-sulfur compounds, formation, spontaneous combustion，potential hazards
Water environment protection in shale gas development
Li Jin1,Sun Gang2,Li Fanshu1（1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, Sichuan, China; 2. Northwestern Sichuan Gas District Purification Plant, PetroChina Southwest Oil & Gasfield Company, Jiangyou 621700, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.3,pp339-344,2014（ISSN 1007-3426, IN CHINESE）
Abstract: As an unconventional natural gas, shale gas has become increasingly important in the world energy resources structure. The US is one of the main nations which get great success in shale gas development. The lack of environment protection regulations in the US were introduced, and features of water environment management in shale gas development were analysed, and treating measures for waste water in shale gas development were also reviewed, which can provide a reference for domestic shale gas development.
Key words: shale gas， hydrofracturing， fracturing liquid， flowback liquid， produced water treatment
