Feb.2015,Vol.44,No.1

CHEMICAL ENGINEERING OF OIL & GAS

ABSTRACTS

Progress of natural gas energy measurement technology

Chen Gengliang(Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp1-7,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Since GB/T 22723-2008 Energy Determination for Natural Gas was issued, a lot of laboratory researches and field tests have been developed as well as many scientific and technological achievements are acquired. Because a series of ISO and foreign advanced standards are not transformed so far, there are some flaws in our technological development of natural gas energy measurement system, such as establishing traceability guideline of natural gas analysis, evaluating measurement error and uncertainty for analysis system, and MonteCarlo simulation for uncertainty evaluation. Four suggestions about technological development in future are presented.

Key words: natural gas, energy measurement, measurement error, analytical bias, uncertainty, MonteCarlo simulation

Synthesis and reaction mechanism study of diethyl polysulfides as mixed sulfiding agent

Xu Haisheng¹， Xu Shiye¹， Shao Jianbo²（1. College of Chemistry and Chemical Engineering, Xi'an Shiyou University, Xi'an 710065, China；2. Geermu Refinery, CNPC, Geermu 816000, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp8-11,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Diethyl polysulfides as mixed sulfiding agent were synthesized by using industrial sulfur from refining enterprises, sodium sulfide and bromoethane  in the presence of phase transfer catalyst tetrabutylammonium bromide. The influences of reaction conditions on sulfur content were studied and the synthesis reaction mechanisms were discussed. The results showed that the ringopening of S8 molecules was the key step of the synthesis reaction and the addition of sodium sulphide greatly reduced the activation temperature of S8. When the molar ratio of S to Na₂S was  4∶1,  the first step reaction temperature was 50 ℃, the first step reaction time was 25 minutes, the second step reaction temperature was room temperature, the second step reaction time was 1.5 hours and the TBAB molar fraction was 4%, the mass fraction of sulfur in diethyl polysulfides reached 63.86%, the flash point was 83.5 ℃ and the oil solubility was good.The reaction has advantages of wide raw material sources, simple synthetic route, mild reaction conditions and environmental friendliness, which has a good development and application prospects.

Key words: diethyl polysulfides, mixed sulfiding agent, synthesis, reaction mechanism

Mineralization process simulation of CO₂ in tail gas of natural gas purification plant by phosphor gypsum combined with ammonia

Lin Ting, Wei Wenyun, Liu Lingling, Yu Hui(School of Chemical Engineering, Sichuan University, Chengdu 610065, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp12-16,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Using CCUS new technology of phosphor gypsum, ammonia combined mineralizing CO₂ in tail gas of natural gas purification plant, and based on estimation of physical parameters and model establishment, the process conditions for making use of the phosphorus gypsum mineralization of CO₂ were optimized with process simulation method. It proposed the optimized reaction temperature was 60 ℃, and the reaction time was 100 minutes. Compared the simulation results of optimized process conditions with the existing technology conditions, it was concluded that the exhaust gas of CO₂, NH₃, phosphor gypsum emissions were reduced by more than 3% compared with the existing process emissions. Aimed at the optimization goal of reducing the energy consumption, the heat exchange network design of whole process can reduce the energy consumption of hot utility by 15% and that of cold utility by 5.6%, respectively.

Key words: phosphor gypsum, ammonia, natural gas purification plant，CO₂, process simulation, heat exchanger network

Discussion on emission reduction of tail gas from natural gas purification plants in southwest China

Yang Wei¹, Chang Honggang¹, He Jinlong¹, Wu Mingou¹, Liu Zhuomin², Chen Chao², Liu Wei³(1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company，Chengdu 610213, China; 2. Exploration and Development Research Institute, PetroChina Southwest Oil & Gasfield Company，Chengdu 610041, China; 3. Natural Gas Purification Plant of Northwestern Sichuan Gas District, PetroChina Southwest Oil & Gasfield Company，Jiangyou 621700, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp17-20,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Based on the investigation of the main tail gas treatment processes of sulfur recovery unit as well as the current emission analysis of the natural gas purification plants in southwest China, the processes of hydrogenation reduction and renewable organic amine were compared. The emission reduction scheme of tail gas was proposed, which could provide a new way to reduce the emission of tail gas from the natural gas purification plants in southwest China.

Key words: sulfur recovery, tail gas, SO₂, hydrogenation reduction, renewable organic amine, emission reduction

Parameters adjustment analysis of desulfurization system of Tahe 2# light hydrocarbon station

Ma Guoguang¹, Cao Lianjin¹, Zhong Rongqiang², Ji Xiaxia¹(1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; 2. Northwest Oilfield Branch, SINOPEC, Urumqi 830000, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp21-24,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Aiming at the fluctuation of H₂S content in natural gas and the unqualified natural gas, the sensitivity analysis of operating parameters that affect the desulfurization device were made. The analysis result indicates that operating pressure, temperature of the absorber and MDEA circulation flow rate have little effect on H₂S content in sweet gas, but operating parameters of regenerator have a great influence on desulfurization effect. Therefore, only operating parameters of MDEA regenerator were adjusted. The results show that when the mass fraction of H₂S in natural gas increased by 58%, it can effectively reduce the content of H₂S in the sweet gas to reach the standard by slightly adjusting operating pressure and temperature of MDEA regenerator.

Key words: desulfurization device, sensitivity, parameter adjustment, H₂S content

Process simulation and optimization to reduce H₂S content in condensate oil

Chen Xin¹, Cao Dong², Wang Tingting¹, Li Li¹, Wen Ke²（1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, China; 2. Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfield Company, Chongqing 401200, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp25-29,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Due to high H₂S content in the stabilized condensate products of an oil and gas processing plant in Central Asia, the high H₂S concentrations in the air around the loading platform during the process of condensate oil loading seriously affect the safety of the operators. The reasons of the ultrahigh H₂S content in condensate oil were analyzed, and the condensate stabilization unit was simulated by HYSYS software. The results showed that without changing the technological process and the process equipments, when the temperature at the bottom of the column was controlled from 155 ℃ to 160 ℃, and the pressure was 0.3 MPa, by adjusting the feed ratio at the top and middle of the column to 1∶1, H₂S content in stabilized condensate decreased from 170 mg/L to 20 mg/L or so, and H₂S was not detected around the loading platform.

Key words: stabilized condensate, H₂S, HYSYS, simulation

Application of hydrogenproducing technology using naphtha or refined naphtha in the startup of continuous catalyst reforming unit

Yuan Chunhua(CPECC EastChina Design Branch (Beijing), Beijing 100101, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp30-34,2014（ISSN 1007-3426, IN CHINESE）

Abstract: The source of hydrogen for the startup of continuous catalyst reforming unit, mechanism and process flow of hydrogenproducing technology using naphtha or refined naphtha, investment of hydrogenproducing technology etc. were discussed. Combined with the startup of two sets newly built hydrogen production device of 600×10³ t/a continuous catalyst reforming unit, the two kinds of startup hydrogenproducing scheme were compared and analyzed. Conclusions are drawn as follows: If the startup hydrogen is difficult to get, a set of hydrogenproducing device for unit startup using naphtha or refined naphtha may be increased. Hydrogenproducing device using refined naphtha is suitable for the refinery with enough refined naphtha. Otherwise, hydrogenproducing device using naphtha should be preferentially considered. The catalyst cost accounts for a high proportion of about 67.48% of the total investment for hydrogenproducing technology.

Key words: continuous catalyst reforming, startup hydrogen, hydrogenproducing by refined naphtha, hydrogenproducing by naphtha

Scheme comparison and selection of heavy hydrocarbon removal process in LNG plant

Zeng Fanping, Tian Guangxin(China Natural Gas Corporation Limited, Chengdu 610100, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp35-38,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Current situation and existing problem of heavy hydrocarbon removal process in the LNG plant were analyzed. Taking the existing devices in Guangyuan LNG plant of China Natural Gas Corporation Limited as example, the processing capacity of which was 1 000×10³ m³/d（at 20 ℃ and 101.325 kPa）, it is helpful to improve the effect of heavy hydrocarbon removal by adding a new adsorption equipment following the dehydration unit. Meanwhile, it can reduce the flow rate of flash gas, increase the liquefaction ratio of the natural gas, and decrease the unit energy consumption, as well as promote keeping the plant for a longterm and stable full load operation.

Key words: liquefied natural gas, heavy hydrocarbon removal, temperature swing adsorption, technical transformation，energy conservation

Study of boil off gas recovery process in LNG repository

Chen Liqiong，Han Xiaoyu，Huang Kun，Wu Xiaonan，Wu Shijuan，Lu Hongfang，Zhu Shujun(School of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp39-44,2014（ISSN 1007-3426, IN CHINESE）

Abstract: The boil off gas (BOG) processing system is one of the key issues directly relating to the energy consumption, safe and steady operation of LNG repository. In order to reduce huge losses caused by the venting of BOG, it is necessary to adopt the BOG recovery technology in LNG repository. To reduce the energy loss caused by the heat leakage, three BOG reliquefaction processes (methane refrigerant liquefaction cycle, the mixed refrigerant liquefaction cycle and nitrogen expansion refrigeration liquefaction cycle) were proposed based on analyzing the BOG recovery methods of LNG repository. Using Aspen HYSYS software to simulate the BOG reliquefaction process, the refrigerant flow and the power consumption of the system needed in three processes were compared and analyzed, and the most suitable BOG reliquefaction process (the mixed refrigerant liquefaction cycle) in LNG repository was determined with the effective energy related theory. The shaft power of compressor is 15.30 kW less than that of the methane refrigerant liquefaction cycle process and 146.42 kW less than that of the nitrogen expansion refrigeration cycle process. Moreover, the effective energy loss of mixed refrigerant cycle system reduced 22.06% compared with that of the nitrogen expansion refrigeration cycle process, and lowered 35.78% than methane refrigerant liquefaction cycle process; the required refrigerant flow was small. It is applicable to LNG repository with large storage scale.

Key words: LNG, repository, BOG, recovery, liquefaction process, effective energy, power consumption of system

Application situation and prospect of LNG industrial chain dynamic simulation platform

Chang Xinjie, Fu Zihang, Cui Feng, Chen Jie(Research and Development Center  of CNOOC Gas and Power Group，Beijing 100028，China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp45-49,2014（ISSN 1007-3426, IN CHINESE）

Abstract: LNG industrial chain is a complicated and systematic engineering. In order to find out the short board links and avoid the risks in the running and management process of LNG industrial chain, LNG production logistics system should be optimized and designed by dynamic simulation. Witness software can be used for secondary development in LNG industrial chain dynamic simulation by comprehending the definition of systematic simulation, comparing and selecting the software which can be used to simulated LNG industrial chain. The complete model structure of LNG industrial chain dynamic simulation system is drawn in the article, and Witness software is secondarily developed by programming language, and the developing idea and method are introduced. The established dynamic simulation platform is tested, and the bottleneck problem and settlement is put forward in the secondary development and application. Finally the application prospect and direction of LNG industrial chain dynamic simulation platform in future is proposed.

Key words: LNG， industrial chain， dynamic simulation，secondary development，application situation

PRICO^® natural gas liquefaction technology and practical application

Luo Shulin, Gai Jingquan, Jiang Hao, Zhang Yuezheng(Black & Veatch Company, Beijing 100022, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp50-53,2014（ISSN 1007-3426, IN CHINESE）

Abstract: PRICO^® is a natural gas liquefaction technology patented by Black & Veatch, 21 sets of LNG factories using PRICO^® technology have been built in cooperation with Chemtex Company in China, 13 of which have been successfully put into operation. PRICO^® liquefaction technology is an open process which is suitable for feed gas with multiple components. The refrigerant loop is a closed adjustable system with single grade mixed refrigerant, it was proved to be mature and reliable, simple and efficient as well as easy to operate. Cold box and refrigerant compressor are core equipment of the technology, which ensure longterm stable operation. Key operations were introduced in the paper, problems encountered in field were investigated, and operation recommendations were provided, which could provide technical and operational guidance for newly built LNG factory and PRICO^® factories.

Key words: PRICO, natural gas liquefaction, LNG, mixed refrigerant, plant operation

Technical research and development of  cryogenically separating LNG from syngas in coaltomethanol

Lai Xiuwen, Zhang Shuwen, Hu Minghui, Chen Bing, Cui Chaoling(Hangyang Limited, Petrochemical Engineering Company, Hangzhou 310000, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp54-58,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Based on a complete set of equipment of  cryogenically separating LNG from syngas in the domestic project from coal to aromatics of 100 000 tons/year which was undertaken by Hangyang Limited, a liquefaction process with expander has been developed. Most of cold capacity was provided by using highpressure nitrogen via the refrigeration circle of turbo expander by adiabatic expansion. Separation of synthesis gas and LNG liquefaction was achieved by using double column cryogenic distillation. When the gas was expanding in the expander, the power was output to drive the supercharger. Compared with the mixed refrigerant process, the liquefaction process with expander has advantages of compact layout, small occupation area, less refrigerant consumption (about 89%), low integrated operation cost, high safety, rapid start, as well as adapting to the varying load conditions from 70% to 110%. It has realized the nationalization of technique and equipment.

Key words: cryogenic separation, methanol syngas, LNG, refrigeration cycle with expander, distillation column

Laboratory evaluation and application of corrosion inhibition and foaming compound agent with temperaturesalt resistant

Li Wei¹，Jiang Zeyin¹，Ai Tianjing²，Chen Nan¹，Su Fuyan¹，Hu Zhiguo²，He Xin²（1.Research Institute of Natural Gas Technology, Petroleum Southwest Oil and Gasfield Company, Chengdu 610213, China; 2.Chongqing Gas District, PetroChina Southwest Oil and Gasfield Company, Chongqing 400021,China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp59-62,2014（ISSN 1007-3426, IN CHINESE）

Abstract: The formation energy and the liquid carrying ability were reduced during the middle or later times of natural gas exploration, which caused serious accumulation of liquid in the down hole and affected the productive capacity of well. Then, foam drainage measures are needed to maintain the normal production of gas well. Due to the existence of H₂S and CO₂, most of the gas field in Sichuan and Chongqing are of high acidity. Therefore, aiming at the gas field of high acidity which is in face of the problems of liquid loading, the study of corrosion inhibition and foaming compound agent could realize the application of corrosion inhibition and foamdewatering gas recovery at the same time. In this paper, the corrosion inhibition and foaming compound agent  named CT5-20 was studied, which was proved to be used under high temperature and high salinity (150 ℃, with salinity of 300 g/L). CT5-20 was used in the testing well of Chongqing gas field, it can be demonstrated that this compound agent can be used in the acid gas field with high salinity and high temperature for corrosion inhibition and foamdewatering gas recovery.

Key words: CT5-20, foaming agent, corrosion inhibition, liquid loading, high temperature, high salinity

Research and application of downhole coupon corrosion monitoring technology in gas well

Chen Jiaxiao^1,2, Cui Xiaoyan³, Chen Zhi^1,2, Zhong Xiaoyu^1,2, Peng Yang^1,2, Jiang Mi^1,2(1. Gas Production Engineering Research Institute, PetroChina Southwest Oil & Gasfield Company，Guanghan 618300，China; 2. National Energy R & D Center of High Sulfur Gas Exploitation, Guanghan 618300, China; 3. Chongqing Gas District, PetroChina Southwest Oil & Gasfield Company, Chongqing 404100,China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp63-66,2014（ISSN 1007-3426, IN CHINESE）

Abstract: As more and more mining of acidic gas reservoir, downhole corrosion prevention and corrosion monitoring are increasingly important. The traditional downhole coupon corrosion monitoring is to hang a piece of coupon installed inside a stationary tubing nipple, but the coupon must be into and up with the tubing in the well. Because the monitoring depth is fixed, the result and analysis of downhole coupon corrosion monitoring are limited by the workover job opportunity. Aiming at the faults of conventional downhole corrosion monitoring as well as the demand of current locale monitoring, a tool for gas well downhole corrosion monitoring was researched and developed independently. The result of indoor evaluation and field test indicated that the tool has the advantages of reliable performance and convenient implement, more real and intuitive evaluation of downhole corrosion, a wide practical range, as well as convenient adjustment for the depth of corrosion monitoring, adjustable number and type, etc. The successful application provides a direct basis for the downhole corrosion inhibition of gas wells and selecting reasonable workover job opportunity, greatly reduces the cost of downhole corrosion monitoring of gas well and overhaul operations, which has an important meaning for gas well safety production.

Key words: corrosion monitoring，wireline operation，throwout，erosion，flow regime，throttling effect，laboratory experiment，field application

Application of hydrogen monitoring technology in sulfur gas transmission pipeline

Yuan Xi¹, Hu Chao⁴, Gu Tan¹, Zhang Qiang¹, Luo Chi², Wang Yue¹, Wang Feng¹, Liu Zhengzheng³（1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfiled Company，Chengdu 610213,China； 2. Chongqing Gas District, PetroChina Southwest Oil & Gasfiled Company, Chongqing 400021, China；

3. Baoji Petroleum Machinery Co., Ltd, PetroChina, Baoji 721002, China； 4．Dianjiang Branch of Chongqing Natural Gas Purification Plant General, PetroChina Southwest Oil & Gasfiled Company, Dianjiang 408323, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp67-69,2014（ISSN 1007-3426, IN CHINESE）

Abstract:  The application effect of corrosion inhibitor was studied and the effective protection time of it was determined in sulfur gas transmission pipeline using corrosion coupon, residual concentration analysis of corrosion inhibitor and hydrogen monitoring technology. The result showed that hydrogen monitoring technology could monitor the corrosion status of sulfur gas transmission pipeline realtime, nondestructively and full phase. The residual concentration analysis of inhibitor and hydrogen monitoring results showed that the effective protection time of corrosion inhibitor could reach more than 1 month.

Key words: hydrogen monitor, H₂S, gas transmission pipeline, corrosion inhibitor

Indoor evaluation and numerical simulation research of CO₂ foam flooding in low permeability reservoirs

Liu Zupeng₁, Li Binfei₂, Zhao Fangjian₁(1. Research Institute of Geosciences, Shengli Oilfield Company, SINOPEC, Dongying 257015, China; 2.College of Petroleum Engineering, China University of Petroleum (East China), Qindao 266555, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp70-74,2014（ISSN 1007-3426, IN CHINESE）

Abstract: CO₂ channeling occurred too early in the pilot test of CO₂ flooding in Yaoyingtai oil field, which decreased its sweeping volume and production capacity. Low permeability fractured core models were generated by core cutting technique. Based on indoor experiments, the foam blocking ability and flooding performance were measured by core flooding experimental apparatus and EOR results of foam displacement following water and gas flooding were conducted. The mechanisms of different components in foam and EOR performance in low permeability fractured reservoirs were analyzed by numerical simulation. The results showed that foam could increase fluid flow resistance in the fracture, reduce liquid motility effectively and resistance factors were between 46 and 80; there was a foam apparent viscosity in the fracture that had an impact on the initial flow of foam. For the oil saturated fractured cores flooded by water and gas, oil recovery was increased by 26% and 35% respectively, and the mechanism of CO₂ foam EOR in low permeability fractured reservoirs was the transverse pressure between facture and matrix.

Key words: lowpermeability fractured reservoir, foam plugging, enhanced oil recovery, foam flooding, numerical simulation

Application of XXP-1 solid defoaming agent in the western Sichuan gas field

Nie Lan¹， Yuan Zongming¹， Yang Jinlin²， Qing Chengfeng²， Zhou Yongchun²(1.State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China；2. Western Sichuan Gas Production Plant of Sinopec Southwest Branch Company, Deyang 618000, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp75-78,2014（ISSN 1007-3426, IN CHINESE）

Abstract:  Aiming at the application restriction of liquid defoaming agent, XXP-1 solid defoaming agent was introduced and field tests were conducted in X5，XC6 and XYHF-2 gas wells of the western Sichuan gas field. The results indicated that XXP-1 solid defoamer has good capacity of breaking bubbles and inhibiting foam generation, the defoaming time of XXP-1 solid defoaming agent was less than 10 s and the inhibiting time was more than 6 min. The height of foam in sewage tank substantially reduced, monthly sewage pull capacity of upstream well station was greatly increased, and the gas outlet pressure dropped and approached to the pressure of pipe network after injecting  XXP-1 solid defoamer. XXP-1 solid defoaming agent could efficiently eliminate the bubble and improve the gasliquid separation efficiency.

Key words: western Sichuan gas field，drainage gas production，foaming agent，foam，defoamer，gasliquid separation efficiency，field test，effect evaluation

Research and application of gel polymer profile control and flooding technology in Shanan oil field

Wu Jianming, Shi Yan, Han Huiling, Wang Hongzhong(Zhundong Production Plant of Xinjiang Oilfield Company, Fukang 831511, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp79-82,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Shanan oil field has the geological characteristics of high temperature, high salinity, low permeability and water sensitivity. In recent years, the production situation is more serious with the degree of water drive decreasing year by year. To improve this situation, the pilot test of gel polymer profile control and flooding technology was carried out in Shaqiu 5 wellblock of Shanan oil field. At first, the water well was made a full profile control with composite organic gel particles profile control agent with a tolerance of temperature and salt, and then oil displacement agent of 0.3% was injected for displacing oil. The Application result showed that this technology has the good effect in enhancing production of oil and precipitation with efficiency of 85.7% for 12 wells among tested 14 well times, and total oil increment was 3 069.6 t. Compared with non experimental area, the level of oil decline in experimental area decreased significantly. The way of profile control and flooding played an obvious role in controlling production of oil.

Key words: low permeability, gel polymer, profile control and flooding, EOR， Shanan oil field

A comparative study on the quality of import biodiesel blend fuel and import diesel

Mu Mingren¹, Zhao Xuerong¹， Zhang Daihua², Hu Xiaojing¹, Dong Weifeng¹, Li Li¹, Zhang Lixia³(1. Liaoning EntryExit Inspection and Quarantine Bureau, Dalian 116001, China；2. Chinese Academy of Inspection and Quarantine, Beijing 100123, China；3. PetroChina Dalian Petrochemical Company, Dalian 116032, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp83-86,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Based on comparison analysis，import biodiesel blend fuel and import diesel had 12 same inspection items, in which 8 inspection items had the same test methods. Most of quality indices of import biodiesel blend fuel were higher or equal to those of import diesel. Technical requirements and inspection results of most items such as 10% evaporation residue carbon pour point and distillation were better than proper items of import diesel. Particularly, for sulfur content, quality index of import biodiesel blend fuel was no more than 0.001 0% (mass fraction), while the inspection result was only 0.000 2% (mass fraction)-0.000 6% (mass fraction), which was much lower than that of import diesel of 0.42% (mass fraction)-0.48% (mass fraction), meeting the requirements of Euro IV and Euro V indices. The import of biodiesel blend fuel creates conditions for improvement of diesel quality, reduction of erosion of engine parts, reduction of pollution emissions, and has better application performance than import diesel.

Key words: biodiesel blend fuel, diesel, quality

Discussion on chromatographic analysis technology of LPG composition

Guo Jingyun(Petroleum Chemical Plant of Shengli Oil Field, Dongying 257000, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp87-92,2014（ISSN 1007-3426, IN CHINESE）

Abstract: This article researched the separation properties of LPG by three kinds of chromatographic column. The separation of propane and propylene in LPG could be improved by using selfmade column of dibutyl phthalate and sebacic nitriles together, so as to quantify the various components accurately. Sebacic nitriles chromatographic column had a high resolution and good repeatability in analyzing all kinds of components except C₂ of LPG and was good for separating hydrogen sulfide from LPG in refinery. The Al₂O₃/PLOT quartz capillary column and FID tested the C₁-C₅ components of LPG more ideally, each component could achieve baseline separation, and the precision of the result was good. The key technologies affecting the accuracy of LPG analysis, such as sampling, injection, results quantification and use of reference gas, were discussed in detail.

Key words: LPG, chromatography, technical discussion

Leakage risk evaluation of buried gas pipeline outside the buildings

Wang Hechao¹, Wu Ming¹, Yang Rui¹, Cheng Mengmeng², Zhang Shangzhou³

(1.Academy of Petrol and Natural Gas Engineering, Liaoning Shihua University, Fushun 113001, China；2. Oil and Gas Storage and Transportation Company of Xinjiang Oilfield Company, Karamay 834000, China；3. Liaohe Oilfield First Construction Engineering Company of Liaohe Petroleum Exploration Bureau, Panjin 124120, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp93-98,2014（ISSN 1007-3426, IN CHINESE）

Abstract: In view of the problem of buried gas pipeline piercing leakage outside the buildings, a threedimensional simulation model was established with Gambit2.4. The continuous leak diffusion circumstance of gas in soil and atmosphere were carried out through numerical modeling by CFD software Fluent 14.0 under different ambient temperature and humidity. The influence factor of gas diffusion and the distribution regularity of concentration were comparatively analyzed under the coupling effect of ambient temperature and relative humidity. The research result showed that the gas ejecting from the leakage mouth first spread rapidly in the soil layer, resulting in the concentration of the upper surface quickly reaching the lower explosive limit and upper explosive limit. As the gas permeating through the earth surface, it influenced both sides of the building. Different concentration diffusion regions also formed on the windward side and the leeward side direction. Affected by different humidity and temperature, for some buildings, the warning concentration on the height of surface changed obviously. The case study results could assess the scope of the gas leak accident and effectively evacuate the masses in time.

Key words: building group, gas pipeline, diffusion, coupling effect, risk, evaluation

Application of HAZOP technology in risk assessment of CNG wells

Liang Guangchuan¹, He Huijuan¹, He Sha², Wen Wen¹, Zuo Guo¹, Hou Xiaoben³（1．Oil and Gas Engineering Institute of Southwest Petroleum University, Chengdu 610500, China；2．CCDC Safety Environment Quality Supervision & Inspection Institute, Guanghan 618300, China；3.Southwest Petroleum Branch of Sinopec, Chengdu 610041, China）. CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp99-102,2014（ISSN 1007-3426, IN CHINESE）

Abstract: HAZOP technology is a qualitative risk assessment method used to identify the design defects, process hazard and operability problems. It mainly finds the consequences and the cause of the accident through deviations, and on the basis of existing protective measures, it proposes the suggestions to control or reduce risk measures. Because of its advantages of systematic and scientific, HAZOP has been widely used in petroleum, chemical industry, etc. In view of the underground gas storage well growing problems such as corrosion, aging, this article used the HAZOP technology to analyze CNG underground gas storage well safety for the first time. The article proposed 94 measures and the adoption rate could reach more than 90%, which provided a strong basis for the production safety management. Meanwhile, the advantages and disadvantages of HAZOP technology were summarized, and the direction of future improvement was clearcut.

Key words: HAZOP, gas storage well, safety, risk, measure

Application of SIL analysis techniques in inservice device of petrochemical enterprises

Li Na¹, Zhang Xue¹, Song Daqing²(1.CNPC Research Institute of Safety & Environment Technology, Beijing 102206, China；2. PetroChina Guangdong Petrochemical Company, Jieyang 515200, China). CHEMICAL ENGINEERING OF OIL & GAS, VOL.44, NO.1,pp103-106,2014（ISSN 1007-3426, IN CHINESE）

Abstract: Hazard and operability analysis (HAZOP) method, as a qualitative hazard analysis method, is difficult to quantify the residual risk. On the basis of that, safety integrity level (SIL) analysis techniques are introduced and briefly described, which include the safety instrumented system (SIS), SIL, and the two steps of SIL analysis: SIL classification and SIL verification. Then, three methods, such as risk matrix, risk map and layers of protection analysis (LOPA), of SIL classification are introduced, as well as the key points of SIL verification. Besides, choosing an interlocking system of inservice device, the process of SIL classification and SIL verification are carried out by examples, and the final results are analyzed. In the end, the article combed the precautions of carrying out the SIL analysis.

Key words: inservice device, layers of protection analysis (LOPA), safety instrumented system (SIS), safety integrity level (SIL), classification, verification