CHEMICAL ENGINEERING OF OIL & GAS
Formation causes and mechanisms study of jelly blockages in natural gas purification units
Yan Xiaoqin1, He Peidong2, He Jinlong1, Zheng Bin3, Li Fuyuan4, Tang Xi2, Tu Chenyuan1(1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, Sichuan, China; 2. Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfield Company, Chongqing 401220, China; 3. Development Department, PetroChina Southwest Oil & Gasfield Company, Chengdu 610051, Sichuan, China; 4. Central Sichuan Oil & Gas District, PetroChina Southwest Oil & Gasfield Company, Suining 629000, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp579-584,2014（ISSN 1007-3426, IN CHINESE）
Abstract: It is a difficult problem in natural gas purification process that jelly blockages affect the normal operation of units. In order to solve the problem, a study on the formation causes of jelly blockages was carried out. Through the determination of jelly blockage composition, the experiments of jelly formation and decomposition, and the research experiments of jelly formation mechanism, it was concluded that long chain carboxylic acids and sodium ions are the key components of the formation of jelly blockages. The formation mechanism of jelly blockages was put forward: After the long-chain carboxylic acid sodium salts having carbon number of 12 or more than 12 in the desulfurization solution form micelles, the relative molecular mass of micelles is more than 10 000, so the Van der Waals forces between them are large enough to connect them one by one. On the other hand, the long-chain carboxylic acid sodium salts are partially ionized, thus the outer surface of micelle is negatively charged. As these micelles are all negatively charged, they repel each other. When the repulsive forces and attractive forces between the micelles reached balance, the micelles could no longer move freely and were bounded at certain positions to form a three-dimensional net-like structure. The aqueous solution was wrapped in this structure and loss its flow ability, and exhibited a semi solid state.
Key words: natural gas, purification unit, jelly blockages, formation causes, mechanism
Analysis of dehydration from CO2 by TEG
Chen Xi1,2, Deng Daoming1,2, Wan Yufei1,2(1. National Engineering Laboratory for Pipeline Safety, China University of Petroleum(Beijing), Beijing 102249, China； 2. Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum (Beijing), Beijing 102249，China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp585-589,2014（ISSN 1007-3426, IN CHINESE）
Abstract: CO2 removed from natural gas decarburization unit or recovered from power plant still contain saturated water. In order to prevent the formation of hydrates, the emergence of two-phase flow and the corrosion of pipeline and equipment when CO2 dissolves in water, gas dehydration process is necessary before pipeline transportation. Herein Aspen HYSYS was used to simulate the dehydration process from CO2, and influence factors of CO2 dehydration were investigated. Under a certain feed rate, through changing the pressure, temperature, number of tray plate in absorber, reboiler temperature and circulation rate of TEG the computed results gave optimal process parameters. The results showed that with the feed gas rate of 466.4×103 m3/d, the working pressure of 2 000 kPa and room temperature for absorber, the tray number in absorber was 8-10, reboiler temperature was 200 ℃, and the circulation rate of TEG was 1.1 kg/kg（water removed）, the water content in the mixed gas could meet pipeline requirements.
Key words: pipeline transportation, CO2, dehydration, TEG, Aspen HYSYS
Simulation study of the flow and combustion in the reheating furnace of Claus sulfur recovery unit
Liu Wenguang1, Xie Hui2,3, Liu Chao2,3（1. China Petroleum Engineering Co., Ltd. Southwest Company, Chengdu 610041, Sichuan, China； 2. Key Laboratory of Lowgrade Energy Utilization Technologies and Systems of Ministry of Education, Chongqing 400030, China； 3. College of Power Engineering, Chongqing University, Chongqing 400030, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp590-594,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Due to the influence of various factors, there exists the local overheating phenomenon in the reheating furnace, which would cause the lining burned to collapse during the Claus production process. The flow and combustion process in the reheating furnace of H-1402（1-6）-H01 were researched with the numerical simulation method. Using FLUENT software, the physical and mathematical models were established to simulate the influence of protection wind on velocity field and temperature field in the reheater under the conditions of four different flow rates of protect wind, and found out the velocity field and temperature field in the reheating furnace and the temperature field distribution of furnace wall. The results showed that an appropriate amount of protection wind could effectively control the wall temperature within a certain range, prevent the furnace from local overheating, ensure the safe and reliable operation of the equipments, and play a guide role in the structure design of reheating furnace and the affiliated burner.
Key words: Claus process, reheating furnace, numerical simulation, protection wind
Establishment and analysis for adaptive model of natural gas desulfurization and decarburization facilities based on RSM
Deng Ji1, Liu Hong1, Chen Haitao2, Zhao Qilong1, Li Linfeng1(1. Southwest Petroleum University, Chengdu 610500, Sichuan, China; 2. Safety and Environmental Protection Quality Supervision ＆ Testing Research Institute, CNPC Chuanqing Drilling Engineering Co., Ltd, Chengdu 618300, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp595-601,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The desulfurization and decarburization devices operate unstably and acidic components are separated excessively when it comes to variation of feed gas conditions. Process model of a desulfurization and decarburization device was established using simulation software and the adaptive model was regressed on the base of RSM. Volume flow rate of feed gas, CO2 volume fraction as the varying parameters of feed gas conditions and DEA mass fraction, location of lean amine into absorber, amine circulation volume rate and energy consumption of the unit were chosen as adaptive variable. Based on the analysis of the model，the results were showed as follows: The increase of processing capacity and CO2 volume fraction will lead to the increase of amine circulation volume rate and energy consumption. Compared with processing capacity, CO2 volume fraction has more influence on the amine circulation volume rate and energy consumption. Rising the location into absorber and increasing DEA mass fraction will both contribute to the decrease of amine circulation volume rate and energy consumption, and the former has slightly more influence than the latter. There is a strong interaction between the processing capacity and CO2 volume fraction on affecting the amine circulation volume rate and energy consumption. The last but not the least, it can be regarded as an efficient way to reduce the influence brought by the variation of feed gas conditions to regulate DEA mass fraction and location of lean amine into absorber.
Key words: desulfurization, decarburization, variation of feed gas composition, adaptability, RSM, H2S, CO2
Application analysis of coiled tubular heat exchanger in natural gas processing
Wang Chuqi1, Ma Ying2(1．China Petroleum Engineering Co., Ltd, Southwest Company，Chengdu 610041, Sichuan, China; 2. International Business Department, CNPC Logging Co., Ltd，Xi’an 710077, Shaanxi, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp602-606,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The performance of coiled tubular heat exchanger in natural gas treatment process is not stable. It shows frequently freezing and big drop in thermal efficiency. Through the analysis of coiled tubular heat exchanger structure and descaling technology, the characteristics of heat exchange, operation and maintenance were mastered. Taking the air precooler of Kelameili Natural Gas Treatment Plant as an example, the causes of the freezing and low thermal efficiency were found out. Combining with the characteristics of coiled tubular heat exchanger and gas treatment process, some suggestions were put forward: According to the gas quality condition, the tube side and shell side was arranged; the impurity in raw gas was controled strictly; and the injection of antifreezer should be uniform. It provides solutions for the safe and smooth operation of the coiled tubular heat exchanger in natural gas treatment process to realize high efficiency and energy-conservation.
Key words: coiled tubular heat exchanger, natural gas, treatment process
Alcohol recovery process optimization of dehydration and dealkylation device of Moshen No.1 Well
Zhao Xiangpo，Duan Xianyong, Wan Xiumei, Yang Hong, Li Jie, Yuan Shunhai
(Moxi Natural Gas Purification Plant of Central Sichuan Oil and Gas District, PetroChina Southwest Oil & Gasfield Company, Suining 629000, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp607-610,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The ethylene glycol injection inhibitors and outside refrigeration technology have been used in dehydration and dehydrocarbon device of Moshen No.1 Well with the capacity of 500×103 m3/d. Owing to the lack of experience in the dosage of glycol, the scraper film evaporator used in alcohol recovery process is one of the difficulties in trial run. Based on the theoretical calculation through analyzing the character of the alcohol recovery processes and calculating the theoretical addition amount of ethylene glycol inhibitors, the optimal operating parameters were explored in the actual operation, which would provide technical support for successful production.
Key words: dehydration, dealkylation, ethylene glycol recovery, scraper film evaporator, hydrate inhibitor
To improve the yield of naphtha pyrolysis butadiene by co-pyrolysis
Xu Jiang, Kong Xiangbing, Tian Liang, Jing Yuanyuan，Mu Zhenzhen, Song Bangyong, Yang Libin（Lanzhou Petrochemical Research Center of PetroChina, LanZhou 730060, Gansu, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp611-614,2014（ISSN 1007-3426, IN CHINESE）
Abstract: A series of co-pyrolysis tests of naphtha and methyl cyclohexane were carried out to study the products yield changes in pyrolysis of different proportions and at different temperatures. The result showed that comparing with the naphtha pyrolysis alone, the yield of co-pyrolysis ethylene decreased while the yield of butadiene substantially increased. Relatively high temperatures are benefit for high butadiene yield while smaller drop of ethylene yield. The co-pyrolysis of naphtha and methyl cyclohexane can optimize the pyrolysis gas product distribution and improve the comprehensive added value of products. It can fully rely on existing ethylene pyrolysis unit and subsequent separation system. Meanwhile, co-pyrolysis has the advantages of high feasibility, lower investment and stable operation, which can meet the requirements of industrial production.
Key words: co-pyrolysis, butadiene, naphtha, methyl cyclohexane, ethylene
Review on production run and technical transformation of Wanzhou Natural Gas Purification Plant
Liao Tie1，Li Fazhang2，Gong Yiran3，Su Mengyao1，Xia Pingqiong4(1. Wanzhou Branch of Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfield Company, Chongqing 404001, China; 2. Research Institute of Natural Gas Technology，PetroChina Southwest Oil & Gasfield Company，Chengdu 610213，Sichuan, China; 3. Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfield Company, Chongqing 400010, China； 4. Dianjiang Branch of Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfield Company, Chongqing 400010, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp615-621,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Since being put into operation in June 2009, the device of Wanzhou Natural Gas Purification Plant has got stable operation and reached design requirements. However, some problems occurred during the production. In combination with 5 year＇s operation situation of the purification plant, the operation characteristics of the process were introduced, some problems occurring during the production were analyzed, and the corresponding improvement measures were proposed, which could provide some references for the design and safe production of similar natural gas purification plants.
Key words: Natural gas, purification plant, high sulfur, technical transformation
Study on liquefying natural gas using differential pressure of gas-distributing station
Ma Guoguang1, Gao Jun1, Ji Xiaxia1, Wei Xiangdong2（1. State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation， Southwest Petroleum University, Chengdu 610500, Sichuan, China; 2. Jiangxi-Hunan Department, WesttoEast Gas Pipeline Company, PetroChina, Nanchang 330000, Jiangxi, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp622-625,2014（ISSN 1007-3426, IN CHINESE）
Abstract: There is huge available pressure energy in the gasdistributing station of the longdistance pipeline of natural gas, so the process of using differential pressure of gasdistributing station to liquefy natural gas were put forward. In the liquefaction technology, mixed amine solution of MDEA (35 wt%)+DEA (5 wt%) was used to remove CO2 and H2S, 4A molecular sieve was used to remove water, and turbine expander was used to liquefy natural gas. At the same time, the impacts of differential pressure and distribution throughput on liquefaction rate were analyzed. The results show that the process is suitable for the gas-distributing station of high pressure drop and large distribution throughput.
Key words: gas-distributing station, pressure energy, purification, pressure differential liquefaction, liquefied natural gas
Technological process and development trend of HCNG filling stations
Yang Taotao, Cui Zhijian，Liu Pei, Yuan Kun, Zhou Jiaming（College of Petroleum Engineering, Xi’an Shiyou University, Xi’an 710006, Shaanxi，China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp626-629,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The advantage and economic feasibility of hydrogen/compressed natural gas (HCNG) are introduced. The main technological process, namely, two kinds of gas are mixed after the mixture pressure reaches a grade, of filling mixed gas of hydrogen/compressed natural gas (HCNG) is analyzed. The main process of primary HCNG filling station，new process technology and ideas are briefly stated. For better using the new energy of energy-saving and emission reduction to realize the industrialization development of HCNG filling station, some suggestions are put forward.
Key words: HCNG filling stations, hydrogen, natural gas, process flow, development tendency
Calculation of the cold loss of 300×103 m3 LNG cold box
Cui Xinting1, Zhang Zhao2（1. ZOKO Energy Equipment Co., Ltd, Hangzhou 310051, Zhejiang, China; 2. Institute of Refrigeration Technology, University of Shanghai for Science and Technology, Shanghai 200093, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp630-633,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Based on three methods of analogy, mathematical models and finite element methods, the cold loss of 300 ×103 m3 LNG cold box were calculated and the results were compared. The results of comparison showed that the cold loss of LNG cold box could be calculated reliably by the analogy with Air Separation Plant (ASP). The fact that the cold boxes of LNG and ASP have the almost same operating temperature is gotten.
Key words: LNG cold box, cold loss, analogy, mathematical models, finite element method (FEM)
Application of propane refrigeration dealkylation process in the No.1 Natural Gas Treating Plant of Amu Darya
Wang Jian(Chongqing Natural Gas Purification Plant General，PetroChina Southwest Oil & Gasfield Company, Chongqing 401259, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp634-638,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The principle of propane dealkylation and the process in the No.1 Natural Gas Treating Plant of the right bank A area of Amu Darya in Turkmenistan were briefly introduced. The process design and production running effects of the past four years were evaluated, and some perfect reforming measures were put forward. The operation management experiences could provide some references for similar dealkylation process design and operation management.
Key words: propane, low temperature, dealkylation process, operation, management
Research and application of a new clean fracturing fluid system
Wang Zhongze1, Huang Jing2, Zeng Hao1, Li Zhizhen2, Xu Kebin1, Qu Xinghua1(1. CNPC Bohai Drilling Engineering Co.,Ltd, Downhole Operation Branch, Renqiu 060552, Hebei, China; 2. College of Chemistry and Chemical Engineering，Southwest Petroleum University, Chengdu 610500, Sichuan, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp639-644,2014（ISSN 1007-3426, IN CHINESE）
Abstract: A new type of clean fracturing fluid was developed by using the electrostatic interactions between molecules and the association of hydrophobic groups. It was evaluated from the facts of high-temperature resistance, shearing resistance, viscoelastic, rheological parameter, loss property, gel break property, salt resistance, and formation damage. The result showed that the viscosity of this new fracturing fluid was over 40 mPa·s by shearing for 1 h at 130 ℃, 160 ℃,170 s-1 respectively, the amount of residue was 0, core damage rate was 21.72%, settling velocity was 1.96×10-4 m/min, filtration coefficient C3 was 7.622×10-4 m/min and the fracturing fluid property was not affected by the salt concentration in water. Besides, compared with guar gum fracturing fluid, this new type of fracturing fluid had the same performance in high-temperature resistance and shearing resistance, and better in core damage rate and gel break property. In addition, when this new type of fracturing fluid was in a faster shearing rate, its viscosity would decrease, and when the shearing rate became slow, viscosity would recover. This character could greatly reduce the friction when the fluid was in tube. Based on above characteristics of this new fracturing fluid, it could completely replace guar gum fracturing fluid. The fracturing fluid acted very well in the test of G34-0X well, and could meet the requirements of field operation perfectly.
Key words: a new type of clean fracturing fluid, association, high-temperature resistance, shearing resistance
Drilling fluid technology of Hashen X1 well
Qiu Chunyang, Ye Hongchao, Wen Shouyun, Wang Baotian, He Xinghua, Si Xianqun(Drilling Engineer & Technology Corporation, Shengli Petroleum Engineering Corporation Limited of SINOPEC, Dongying 257064, Shandong,China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp645-650,2014（ISSN 1007-3426, IN CHINESE）
Abstract: IIn order to understand the situation of oil and gas in Hasan front punching section, and discuss the feasibility of drilling extended-reached well in high dip angle structure, Hashen X1 well was drilled. Aluminum amine collapse prevention drilling fluid system was developed to ensure Hashen X1 well drilling successfully. The evaluation results show that the drilling fluid system has great inhibitive, anti-caving ability, and good lubrication performance. In the field, measures of rational density supporting, multiple improved inhibition, double agent sealing, and lubrication preventing collapse were used, and with corresponding drilling site maintenance process,target stratum was drilled successfully. Problems of wellbore stability, hole cleaning and lubricating to anti-sticking were solved during the course of drilling well in high dip angle block. At last, drilling efficiency increases by 10%.
Key words: Hashen X1 well, borehole stability, faultage, borehole cleaning, lubrication and anti-sticking
Research of pomegranate peel as inhibitory additive for drilling fluid
Zhao Wei1, Chen Gang1, Zhang Jie1, Zhang Jianjia1, Tang Deyao2, Zhao Jingrui2(1. College of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, Shaanxi, China; 2. Shaanxi Yanchang Petroleum Oilfield Chemical Technology Corporation Limited, Yan’an 717400,Shaanxi, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp651-656,2014（ISSN 1007-3426, IN CHINESE）
Abstract: IPomegranate peel powder is used as drilling fluid additive, and the performance of it is evaluated. The results show that pomegranate peel has better effect of reducing fluid loss, and temperature resistance can reach more than 170 ℃. Pomegranate peel has good compatibility with modified starch, good capacity of reducing viscosity, reducing fluid loss at room temprature and 120 ℃ ageing slurry; and the compatibility with polyacrylamide is poor. Mud ball experiment and linear expansion experiment show that the water extract of pomegranate peel can inhibit the swelling of clay, and with the increase in quantity of pomegranate peel, the inhibition effect is more obvious. Particle size analysis indicates that pomegranate peel has certain flocculating effect with the clay in drilling fluid, which can significantly improve the average particle size of clay.
Key words: pomegranate peel, water-based drilling fluid, reducing viscosity, reducing fluid loss, particle size
Influence of surface wettability on devices scaling in ASP flooding
Sun Yan’an1,2, Li Chunfu2, Chen Xiaodong2(1. Oil Production Technology Research Institute of Daqing Oilfield Company Ltd.，Daqing 163700, Heilongjiang, China; 2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp657-661,2014（ISSN 1007-3426, IN CHINESE）
Abstract: By testing contact angles on surface, observing surface microstructures with scanning electron microscopy and analyzing surface dirt with XRD, the influences of fouling resistance with different treatment of equipment surface were studied in the mixed liquid of simulation ASP flooding fluid with formation water. The results showed that the formation of dirt on solid surface was closely related to the degree of water wetting the surface. Hydrophilic surface easily absorbed the dirt particles, and was conductive to the growth of crystallization fouling; and hydrophobic surface contacted with dirt particles difficultly, the adsorption of dirt particles and the growth process of crystal were difficult, but the effect of different surface on dirt polymorphs was little. The changes of surface micro-structural after different surface treatments largely impacted on the surface wettability. By reducing the water wettability of equipment surface would enhance the anti-fouling ability of equipment surface.
Key words: solid surface, contact angle, surface microstructure, deposition and adsorption, fouling resistance
Study on expansion property of pre-crosslinked particle gel with low elasticity and high viscosity
Kang Wanli, Xu Hao, Yang Hongbin, Zhao Wenyue, Du Shanshan, Gong Xiaoya, Liu Xueqi(Enhanced Oil Recovery Research Institute, China University of Petroleum (Beijing), Beijing 102249, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp662-665,2014（ISSN 1007-3426, IN CHINESE）
Abstract: In recent years, because high water content and water channeling have become major problems in oilfield, pre-crosslinked particle gel(PPG) technology has become one of highspeed growing deep flooding technology. Weighing method was used to study the expansion properties of PPG. The effects of PPG preparation conditions and external environmental factors on expansion property of particles were analyzed completely. The experimental results show that, at the PPG preparation conditions, as the increase of mass fraction of acrylamide and crosslinking agent, and the decrease of mass fraction of the initiator, the particle expansion ratio decreases gradually; as the increase of surfactant and ionic content, the particle expansion ratio decreases; as the increase of temperature and pH value, the expansion ratio of the particles also increase.
Key words: precrosslinked particle gel，expansion property，preparation condition，external environment，flooding technology
Performance research of latex cement in extended-reach well
Zhang Zhijian1, Lei Xinyu1,2, Du Zicheng1, Cao Chengzhang3, Li Wentao4, Chen Dajun1(1. College of Chemistry and Chemical Engineering，Southwest Petroleum University, Chengdu 610500, Sichuan, China; 2. Chendu Institute of Organic Chemistry, Chinese Academy of Science, Chendu 610041, Sichuan, China; 3. Sinopec Shengli Oilfield Drilling Technology Research Institute, Dongying 257000, Shandong, China; 4. Drilling Fluid Branch of Great Wall Drilling and Exploration Co., Ltd, Panjin 124010, Liaoning, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp666-669,2014（ISSN 1007-3426, IN CHINESE）
Abstract: IFor the cementing of extended-reach well, it’s easy to form free fluid channel in the upper annulus during the coagulation of solid slurry. At the same time due to the effect of gravity, upper and lower sides of the annular are easy to form the density difference, which leads low cement strength and high permeability of the upper annular with interporosity flow. This seriously affects cementing quality and subsequent operations to increase production. A latex cement formula with zero drainage, low water loss, high compressive strength over 21 MPa for 24 h and permeability below 0.001×10-3 μm2 was designed by using novel latex BCT-800L. Triaxial rock mechanics test system and SEM were used to analyze the mechanical deformation behavior, and microstructure of the latex cement. The experimental results and preliminary mechanism analysis showed that the latex could improve the stability of cementing fluid and mechanics performance of cement, decrease the density difference in upper and lower sides of the annular, reduce the permeability of cement by changing the particle retardant migration and polymer filming, and prevent fluid channeling through cementing transformation.
Key words: extendedreach well, latex cement, mechanical properties, microscopic analysis
Experimental study of ZSJJ-3 type polymer plug remover
Li Ping(Gudao Oil Production Plant of Sinopec Shengli Oilfield Company, Sinopec,Dongying 257231,Shandong, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp670-674,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Aiming at the problems of high injection pressure and serious short of injection during polymer flooding and subsequent water flooding in Shengli Oilfield, this paper analyzes the reasons of reservoir plugging and under injection，the composition of polymer plug on site, combining with the hidden danger in application of ordinary oxide polymer plugging remover，a new type of polymer plugging remover was developed, and its performance was evaluated. Depolymerizing agent is inactive at room temperature, security and stabilit. It can release oxygen free radicals at reservoir temperature, dissolve polymer blockage near wellbore area，and degrade polymers into small molecular polymers. The capacity of dissolving polymer blockage and viscosity reduction rate is more than 90% respectively. In the application of field test, the pretreatment process and stabilization process have been matched in later period based on actual situation, by which, it could remove plug and stimulate injection for polymer injection wells and the subsequent water flooding under injection wells. The effect of augmented injection was enhanced, and the validity period of stability injection was extended.
Key words: polymer flooding and post flooding, polymer plug, polymer plug remover, oxygen free radical, performance of polymer plugging removal, dissolution degree
Sampling and determination of trace ethylene glycol in natural gas
Han Hui1,2, Wang Xiaoqin1,2（1.Research Institute of Natural gas Technology of PetroChina Southwest Oil & Gasfield Company，Chengdu 610213, Sichuan, China; 2．Natural Gas Quality Supervision and Inspection Center for Pertoleum Industry, Chengdu 610213, Sichuan, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp675-678,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Natural gas after produced is often served as a hydrate inhibitor by manual injection of ethylene glycol to prevent plugging of equipment and pipeline. The viable and effective method was established for sampling and determination of trace ethylene glycol in natural gas. It’s beneficial guidance to the injection amount of ethylene glycol. The trace ethylene glycol in natural gas was enriched with the solvent desorption silica gel under pipeline pressure, and then desorption liquid was analyzed by gas chromatography after desorbing. The detection limits of ethylene glycol can reach 0.05 mg/m3 when the sample volume is 10 m3 and the liquid used for desorption is 10 mL.
Key words: natural gas, ethylene glycol, sampling, gas chromatography, analyze
Design and experiment of natural gas online moisture content/water dew point conversion instrument
Zhang Xinhu1, 2, Li Zhenlin2, Duan Menglan1, 2, He Bin3(1. Offshore Oil and Gas Research Center, China University of PetroleumBeijing， Beijing 102249, China； 2. College of Mechanical and Transportation Engineering, China University of PetroleumBeijing， Beijing 102249, China; 3. Research Institute of Natural Gas, PetroChina Southwest Oil & Gasfield Company, 610213, Chengdu. Sichuan). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp679-683,2014（ISSN 1007-3426, IN CHINESE）
Abstract: The moisture content and water dew point of natural gas are keys to its pipeline transportation. At present, the conversion software within natural gas moisture and dew point instrument has low accuracy. In order to solve this problem, an instrument of conversion for natural gas moisture content/water dew point based on OPC communication has been designed and developed. The experiment showed that the instrument could run real-time online and had good computational accuracy and efficiency.
Key words: natural gas, moisture content, water dew point, conversion instrument, OPC communication
Study on accuracy of natural gas flow measurement in LNG terminal
Cheng Yongqiang, Cui Jing, Zhang Lin(PetroChina Dalian Liquefied Natural Gas Company Limited, Dalian 116600, Liaoning, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp684-688,2014（ISSN 1007-3426, IN CHINESE）
Abstract: IThe gas metering related to the LNG terminal includes port metering, transmission metering, tank metering and process metering. Port metering and transmission metering used for trade metering require accurate and reliable measurement results. The density measurement error generated from gas component analysis can lead to the mass flow metering error in transmission metering. Due to the assignment allowed for volume of tank in calibration may cause stocktaking error, it is recommended to re-calibrate the volume of tank after commission to reduce measurement error. Because of differences in the density of LNG, the measuring of Venturi mass flow meter is likely to cause measurement error in process metering.
Key words: flow measurement, measurement error， accuracy, stocktaking error
Treatment of waste water from recirculating cooling system in LNG plant using electrodialysis technology
Wang Dan，Tong Fuliang，Wang Yan，Yang Xiaojiao(Southwest Company of China Petroleum Engineering Co.,Ltd, Chengdu 610041, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp689-692,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Waste water from recirculating cooling system in Hubei LNG plant amounts up to 1 200 m3 per day. Direct discharge would not only cause the waste of water resource, but also bring large impact to the operation of the downstream sewage treatment plants. In order to promote the recycling rate, a “multi-stage continuous electrodialysis desalination system” was designed to treat the waste water for reusing. According to the design calculation, the flow velocity, the overall desalination rate, the conductivity of the treated water were set at 5.0 cm/s, 75%~80%, and 300~350 μs/cm respectively in 50 m3/h electrodialysis system. The debugging results showed that the optimum operating voltage was 110 V, the most suitable flow rate was 50 m3/h, and the treated water from the electrodialysis system could meet all the design requirements. The process can reduce the fresh water consumption and waste water discharge by 300 000 tons per year respectively, and bring direct economic benefit of about RMB 600 000 yuan each year.
Key words: electrodialysis, LNG, waste water, recirculating cooling water
Application of stability control technology of injection water quality in Xinjiang Oilfield
Yan Zhong1, Qu Jing1, Hu Jun1，Zailafu·Wubuaishan1, Luo Bingrui2（1.Research Institute of Experiment and Detection of Xinjiang Oilfield Company，PetroChina, Xingjiang 834000,China; 2. Engineering Technology Research Institute of Xinjiang Oilfield Company, PetroChina, Xingjiang 834000,China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp693-699,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Due to the harmful and instable produced water from some blocks of Xinjiang Oilfield, combined with matching process can not effectively solve the existing problems, the quality of injection water at wellhead can not be stable up to standard for a long time. By laboratory research and analysis, the key factors influencing injection water quality stability are water secondary pollution in long-distance pipeline network, inherent instability of the outer water, easily oxidized reducing ions in water, as well as serious carbonate scaling trend. After optimal screening, the response fouling control technology, electrolytic disinfection technology, air oxidation technology are determined, the right treatment process and supporting new pharmaceutical formulation system are developed, which provide technical support for long-term water injection stability of Xinjiang Oilfield and improve the effect of oil field water-flooding.
Key words: Xinjiang Oilfield, quality of injection water, bacterial, scaling, stabilization technology of water quality
Research on land reclamation techniques of oil and gas wellsite in Sichuan and Chongqing area
Wang Hongjuan1, Feng Jun2, Zhang Bo3, Du Hongyao1(1.Research Institute of Safety, Environment and Technology Supervision of PetroChina Southwest Oil & Gasfield Company，Chengdu 610041, Sichuan, China; 2．Production Running Management Department of PetroChina Southwest Oil & Gasfield Company，Chengdu 610051, Sichuan, China; 3．CCDC Sichuan Petroleum Construction Co., Ltd
Chengdu 621000, Sichuan, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.43, NO.6,pp700-704,2014（ISSN 1007-3426, IN CHINESE）
Abstract: Sichuan and Chongqing are the main gas production areas in China, and are abundant in oil and natural gas resources. It is important to protect the scarce arable land resources in oil and gas exploitation process. Therefore, it is of great significance to advance the land reclamation work of drilling wellsite. The land damages of drilling wellsite in Sichuan and Chongqing area are analyzed, and the corresponding measures and technology of land reclamation are discussed from the engineering, chemical and biological aspects. In addition, some suggestions are proposed to the typical problems in land reclamation.
Key words: Sichuan and Chongqing area, land reclamation, land damage, reclamation technique