ABSTRACTS

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1 Gas Hydrate Accumulation Conditions between Qilian Mountain and Wuli Permafrost Region in Qinghai-Tibetan Plateau

GONG Jianming,ZHANG Jian,CHEN Xiaohui,LlAO Jing,Ll Xiaoyu,HE Xingliang,JlANG Yubo (First Author's Address:The Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology;Qingdao Institute of Marine Geology, Qingdao 266071,Shandong,China)

Abstract:In order to study the similarities and differences of gas hydrate accumulation conditions in Qilian Mountain and Wuli Permafrost Region in Qinghai-Tibetan Plateau,its geotectonic location,temperature and pressure conditions and genetic types of gas sources were studied and compared.The results showed that the temperature and pressure conditions there were suitable for gas hydrate formation,the condition of Wuli Permafrost Region was the best.However, there existed considerable differences in geotectonic locations,sedimentary formation,source genesis and its gas sources origins and preservative conditions between Qilian Mountain and Wuli Permafrost Region.Comparatively speaking,the tectonic activities of Qilian Mountain Permafrost Region were weaker,the preservative conditions for gas and gas hydrate was better.While in Wuli Permafrost Region,its tectonic activities were stronger with longer sustaining time and the development of deeper and bigger faults,which was not beneficial for the preservation of gas and gas hydrate.The gas hydrate in Qilian Mountain Permafrost Region was hydrocarbon gases belonging to organic origin,while the gas sources of cores and lake water from Wuli Permafrost Region were carbon dioxide of inorganic origin.Therefore,the studied results show that the tectonic activities and genetic types of gas sources are main factors influencing the gas hydrate accumulation in Qilian Mountain and Wuli Permafrost Region.

accumulation condition;gas hydrate;Qilian Mountain Permafrost Region;Wuli Permafrost Region,Qinghai-Tibetan Plateau

6 Comparative Study of Forming Conditions and Distribution of Large Gasfields in the Northern Carnarvon and Bonaparte BasinsXU Xiaoming,YU Shui,LUO Zongqiang,KANG Hongquan (First Author's Ad dress:General Research Institute,CNOOC, Beijing 100027,China) Abstract:The difference on the tectonic evolution,sedimentary evolution,source rocks,source-reservoir-cap assemblage,trap conditions,reservoir-forming process and its preservation conditions in the North Carnarvon and Bonaparte Basins were analyzed,a comprehensive evaluation was performed.The result shows that the northwest shelf of Australia has the conditions to form giant gasfields,including abundant gas resource,good reservoir,effective cap rock,beneficial reservoir forming condition and configuration as well as late accumulation.At the same time,it is found out that there exists difference between the two basins,in North Carnarvon Basin,2 sets of major source rocks and many reservoir forming assemblages are developed,where tectonic activities are weak,preservation conditions are favorable,it has the greater exploration potential at the late stage. Key words:giant gasfield;comparison of reservoir forming condition;Bonaparte Basin;North Carnarvon Basin

12 Sedimentary Characteristics of the Third Member of Liushagang Formation of M1 Oilfield in WZ11 Area

SUN Tianjian,YU Xinghe,Ll Shengli,Ll Mao,WANG Zhenjun (First Author's Address:Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China)

Abstract:There existed bigger difference in sedimentary characteristics and its microficies types and genesis of the third member of Liushagang Formation in M1 Oilfield of WH11 Area were not clarified.Based on the core and geologic logs and well logging data,the lithology and sedimentary structure,particle size and logging curve features of the third member of Liushagang Formation(El3)were contrasted and analyzed,3 subfacies and 5 microfacies were identified.El3experienced the evolutional process of water subsidence,advance and water regression.The lobate shape deposited sand is created at the stage of water regression,branch-type sand in sand-mud interlayers is created at the early stage of water advance,the interbed of thin sand which is sand-in-mud bird-foot shape deposited at the middle stage of water advance and the early stage of water regression,the thin sand of bird-foot shape sand is created at the middle and later stages of the water regression.

Key words:Weizhou;braided river delta front;sedimentary characteristics;sedimentary evolution

19 Source Rock Evaluation of Well Delo-1 in the Southern Sag of Bonger Basin in Chad

Ll Huijuan,WEN Zhigang (First Author's Address:School of Earth Environment and Water Resources,Yangtze University, Wuhan 430100,Hubei,China)

Abstract:Based on geochemical data of organic carbon content and pyrolysis etc,the source rocks of Well Delo-1 in the southern sag of Bonger Basin were evaluated from abundance and maturity of the organic matter.The results show that the dark mudstones in source rocks of Well Delo-1 are thicker,the organic matter abundance is high and each zone reaches the standard of mid-good source rocks,some reach the excellent standard.The organic type is mainly PypeⅠ-Ⅱ1and some of the Kubla Formation are PypeⅡ2,the organic matter evolution is at low mature-mature stage,Baobab Formation and Ronier Formation are at low mature stage and Kubla Formation is at mature stage.With the increase of depth,the maturity increases.

Key words:Bonger Basin;southern sag;Well Delo-1;source rock evaluation

23 Geochemical Characteristics of Light Hydrocarbons in Dawanqi Oilfield

Jl Hong,HUANG Guanghui,CHENG Dingshu (First Author's Address:School of Earth Environment and Water Resources, Yangtze University,Wuhan 430100,Hubei,China)

Abstract:The light hydrocarbon fraction,Mango parameter and maturity of 80 oil samples from Dawanqi Oilfield of Kuche Depression were analyzed.The analysis result shows that the crude oil samples are rich in cycloalkane,benzene and methyl cyclohexane are over 50%,it presents a terrestrial humic feature.K1is 1.03 in average in the Mango light hydrocarbon parameter,it presents that the sedimentary environments for crude oils are similar,and tricyclic carbon preference index is higher that of pentagonal and hexacyclic carbons,indicates that it is related with terrestrial lacustrine sedimentary environment.The maturity parameter,mass fraction of heptane and isoheptane value,demonstrate that the crude oil belongs to normal mature.The temperature of crude oil generation is between 126.3～157.6℃.

Key words:Dawanqi Oilfield;crude oil;light hydrocatbon;geochemistry

27 Analysis on Controlling Factors and Sandstone Reservoir Characteristics of the Upper Paleozoic in Ordos Basin

ZHOU Jinsong,WANG Nianxi,ZHAO Qianping,LlN Guifang,YlN Xiao,GAO Fei,WEl Hu,HAN Xiaoqin (First Author's Address:Research Institute of Exploration and Devlopment,Shanxi Yanchang Petroleum Group,Xi'an 710075,Shaanxi, China)

Abstract:Lithologic,physical property,pore structure and pore types of the main gas zones of the upper Paleozoic System in different blocks of Ordos Basin were studied by analyzing a large number of thin sections,physical property and mercury injection data,the influence factors of reservoir clastic components,reservoir properties and its plane distribution were studied.The results show that heterogeneity is strong in the upper Paleozoic sandstone reservoir,it generally has the characteristics of low porosity and low permeability and small pore throat.Sandstone components are controlled by the source system,quartz content is reduced from the west to the east and debris content is raised,feldspar content is higher only in the west of the basin's edge,diversity of depositional system determines the diversity of reservoir types and distribution;the influence of diagenesis on the reservoir is from various areas,secondary pores produced by corrosion is the main reservoir space.

Key words:Ordos Basin;Upper Paleozoic System;reservoir characteristics;controlling factor

34 Composite Facies-controlled Modeling Using Coupling Model of Sedimentary Microfacies——A New Approach of Conglomerate Reservoir Modeling

SUO Chao,YlN Zhijun,ZHU Ruizhe,QlN Jianhua,CHEN Yuchuan,WANG Zheng,ZHOU Lianmin (First Author's Ad dress:College of Geosciences,China University of Petroleum,Beijing 102249,China;SinoChem Petroleum Exploration&Production Co,Ltd,Beijing 100031,China)

Abstract:Aiming at the characteristics of fast changing lithologies,complex conglomerate distribution and serious heterogeneity in conglomerate reservoirs of Junggar Basin,Upper Karamay Formation reservoir in No.8 Region of Karamay Oilfield was taken as an example,model based reservoir genetic types and lithologies were established by using sedimentary microfacies model coupling with lithologic facies model,more accurate reservoir attribute parameter models constrained by genetic rock facies model were established.The idea of 3D fine modeling for conglomerate reservoirs better characterizes the reservoir heterogeneity,it provides reference for reservoir adjustment and prediction of remaining oil distribution and as well as for modeling the reservoirs with the same geological characteristics.

Key words:conglomerate reservoir;facies control;reservoir modeling;sedimentary microfacies;lithologic facies;coupling

40 Quantitative Evaluation Method for Low-porosity and Low-permeability Conglomerate Reservoirs

Ll Hongnan,FENG Meng,HU Guangwen,Ll Xuebin,WAN Xuerong,ZHANG Ye (First Author's Address:China University of Petroleum,Qingdao 266580,Shandong,China)

Abstract:Low-porosity and low-permeability conglomerate reservoirs were developed in Baikouquan Formation of Triassic System in Mabei Slope,it was difficult for development.For the purpose of searching for high production layer and providing reliable basis for deployment arrangement of the oilfield at the late stage,a quantitative evaluation was performed reservoir evaluation in Baikouquan Formation.In combination with dynamic and static data analyses,the idea of integral analysis of multi-parameters and formation test data were carried out for optimizing sedimentary micrifacies, product of average permeability and flow zone index,product of nuclear magnetic porosity and thickness,amount ofτ2peak,rate of pressure recovery and the form of its curve,oil-bearing level and formation resistivity as the evaluating indexes.Classification criteria of the indexes were determined and reservoirs in Baikouquan Formation were divided into four categories through integral fuzzy evaluation.The results show that the evaluation result is coincident with that of actual well testing,good result is obtained in application.

Key words:low-porosity and low-permeability;conglomerate reservoir;Mabei Slope Area;Baikouquan Formation; quantitative evaluation

45 Characteristics of Formation Water of Chang 8 Reservoir in Jiyuan Area of Ordos Basin

Ll Jihong,HUl Xiao,CHENG Dangxing,ZHAO Yande,ZHANG Xuefeng (First Author's Address:Research Institute of Exploration and Development,Changqing Oilfieid Company,CNPC;National Engineering Laboratory for Exploration and Development of Low-permeability Oil&Gas Fields,Xi'an 710018,Shaanxi,China)

Abstract:Based on the techniques of physical and chemical property analysis of formation water,the distribution rules of formation water and the relationships between formation water and reservoirs of Chang 8 Reservoir Group in Yanchang Formation of Jiyuan Area were studied in detail.The results show that the formation water in the studied area belongs to conventional water of oilfields,calcium chloride is the main type of water,the water salinity is higher contents in plane but lower on both sides,presents banded distribution from south to north.Coefficient of sodium and chlorine presents higher in the west and lower in the east.The distributive pattern is controlled by the faulted zone in the western margin and Tianhuan Depression structure.According to analytical result of isotope of hydrogen and oxygen from inclusion of oil and gas,it is indicated that the sedimentation water presents characters of mixed flow,which indicates there exists some water coming from the earth's surface in oil migration,and reservoir sealing property is poor at the early stage.

Key words:formation water;oil reservoir;oil and gas inclusion;Jiyuan Area;Ordos Basin

50 Sedimentary Characteristics of Cretaceous Qingshuihe Formation in Block 4 of Central Junggar Basin

CHEN Lin,SUN Yi,XU Tao,ZHANG Xinjian,CHENG Changling (First Author's Address:New Prospect Research Center,Shengli Oilfield Company,SINOPEC,Dongying 257000,Shandong,China)

Abstract:The Cretaceous System of Block 4 in Central Junggar Basin was a potential formation.But its research degree of sedimentary characteristics was relatively low,which restricted the exploration process of this area.According to well logging,borehole logs and seismic data,the sequence characteristics and sedimentary facies of Qingshuihe Formation of Cretaceous in Block 4 of Central Junggar Basin were studied.The results show that Qingshuihe Formation could be divided into two third-order sequences,thus it could be divided into 2 members,such as K1q1and K1q2.Within each third-order sequence,it can be further divided into transgressive system tract and regressive system tract.Braided river sediment was mainly developed in K1q1,where sand body had big thickness and wide distribution,the main exploration targets were to search for low-relief structural traps and lithologic overlap traps.And delta-shore and shallow lake sedimentary systems were mainly developed in K1q2,where reservoirs were not integrally developed,the main exploration targets were lithologic traps formed by delta and beach bar sand.On the phase sequence,the delta-shore and shallow lake sedimentary systems in K1q2directly cover the braided river sediment of K1q1,which is reasonable in the studied area.

Key words:Central Junggar Basin;Cretaceous;Qingshuihe Formation;sequence division;sedimentary facies;sedimentary mode

56 Broadside Seismic Exploration and Its Application in Low-permeability Reservoir Development

ZHANG Jie,ZHAO Deyong,WANG Daxing,ZHAO Yuhua,ZHANG Zhenhong,HUANG Ligang,ZHU Jun (First Author's Address:Research Institute of Exploration and Development,Changqing Oilfield Company,PetroChina,Xi'an 710021, Shaanxi,China)

Abstract:Broadside seismic exploration was a new method for the area of complex surface condition,horizontal layer and low exploration cost.It had the characteristics of broadside observation and multi-directional acquisition,its receiving was parallelly deviated from excitation line,which could keep away the strong secondary inference induced from wellhead and surface strata.Based on the derivation of time-distance curve of the broadside seism,the principle of broadside seismic exploration was introduced,and by comparison with 2D and 3D seismic explorations,the characteristics of broadside seismic exploration as well as the application conditions and geologic problems that solved by broadside seismic exploration were described.The method of broadside seismic exploration could be used to improve the seismic quality of complex near surface and solve the problems of structure,palaeogeomorphologic scratching,reservoir prediction and detection of oil-bearing zones.The method of broadside seismic exploration is used in Ordos Basin,it demonstrates that the technique can be used for low-permeability reservoir development and better effect is obtained in application.

Key words:broadside seism;Ordos Basin;low-permeability oilfield exploration;reservoir prediction;oil-bearing detection

62 Application of Improved Guotao Algorithm in Residual Static Correction

CAO Zhonglin,ZHOU Qiang,LYU Wenbiao,ZHANG Hua,CHEN Aiping (First Author's Ad dress:Sichuan Geophysical Company,Chuanqing Drilling Engineering Company Ltd,CNPC,Chengdu 610213,Sichuan,China)

Abstract:Residual static correction was the key to process the low signal-to-noise ratio seismic data.The traditional residual static correction was easy to fall into the local value,and it was difficult to realize the global optimization,which would result in bad stacking of imaging effect.To solve these problems,a non-linear inversion method of residual static correction was proposed.In this method,the cross-correlation value was the maximum objective function,the optimal residual static correction value was searched by the GT(Guotao)Algorithm with variable search intervals for global optimization.The theoretical model and test of low-signal-noise data show that the method is better than the traditional residual static correction,its convergence in global range is rapid,and can greatly improve the imaging quality of the low signal-to-noise ratio seismic data.

Key words:improved GT Algorithm;inversion;residual static correction

66 Identification of Volcanic Rock Interlayer by Using Frequency-shared Inversion and Model Forward

Ll Daoqing,WANG Bin,QlU Peng,SU Hang,DU Qingxiang,ZOU Mingde (First Author's Ad dress:Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,Xinjiang,China)

Abstract:The study of distribution characteristics of the interlayer in volcanic reservoir was at an exploratory and qualitative description stage,there was few means of quantitative distinguish,so in the process of effective development of low permeability thin volcanic gas reservoirs,interlayer identification was a new hotspot and difficulty.Based on analysis of volcanic reservoir and interlayer of Wellblock Dixi 17 in Kelameili Gasfield,the method of frequency-divided attribute inversion combined with forward modeling method could effectively identify the interlayer of volcanic reservoir and its distribution characteristics,and it greatly improved the vertical and horizontal resolution of seismic inversion.The method is used for volcanic reservoir development,good application effect is obtained,it is of great significance for popularizing the interlayer identification in volcanic gas reservoirs and for guiding the gas reservoir development.

Key words:low permeability volcanic rock;frequency-divided inversion;forward modeling;interlayer identification; horizontal well development

70 Application of Static Correction of Near-trace Constrained Tomographic Inversion in Complex Area of Tarim Basin

ZHANG Kaituo (Author's Address:Research Institute of Petroleum Exploration and Development,Northwest Oilfield Company,SINOPEC,Urumqi 830011,Xinjang,China)

Abstract:Static correction problem was serious in Tarim Basin with acute and rugged topography and sharp lateral variations of near surface velocity.The basic principles of static correction technique of near-trace constrained tomography

were described.The application result in complex near-surface areas of Tarim Basin was provided.The effect of correction and near surface modeling accuracy by tomography inversion with and without near-trace constrained conditions was contrasted.Study result indicates that the near-trace constrained tomographic inversion static correction technology has a obvious technological advantage for solving the static correction problem in complex areas of Tarim Basin.

Key words:tomographic inversion;near-trace constrain;static correction;Tarim Basin

73 Analysis and Application of Lamination Features in Electrical Imaging Logging

ZHANG Xiang,WANG Dilin,SONG Chun'an (First Author's Address:Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education;School of Geophysics and Oil Resources,Yangtze University, Wuhan 430100,Hubei,China)

Abstract:Electrical imaging logging could provide intuitive,clear,high-resolution images of the surrounding strata of the well.The logging imaging could reflect geologic information of the formation.The lamination features were extracted in the imaging logging images by using autocorrelation function which was based on statistic model.These texture features reduced by principal component analysis(PCA)were used to identify lithological property.The logging data process results show that the lamination show that texture features in electrical imaging logging based on the statistic model can effectively reflect the lithological property.

Key words:electrical imaging logging;lamination;feature extraction;lithology;PCA

78 Method for Determining Oil Saturation of Low Resistivity Reservoir in MQ Area of Jinhu Depression

JlANG Aming (Author's Ad dress:Geological Scientific Research Institute,Jiangsu Oilfield Company,SINOPEC,Yangzhou 225009,Jiangsu,China)

Abstract:In MQ area,oil saturation in low resistivity reservoirs of the 3rdmember of Funing Formation of Palaeagane System(E1f3)was mainly affected by the lithology,physical property and logging factors.In allusion to the issue of lower oil saturation calculated by conventional Archie equation,the capillary pressure curve method,relative permeability curve method and logging data optimization method are used to determine the oil saturation in low resistivity reservoirs,it effectively avoid the factors causing low resistance factors,thereby the accuracy of the calculation of the oil saturation is improved.

Key words:low resistivity reservoir;oil saturation;capillary pressure curve;relative permeability curve

84 Two Notes about the Application of Capacitance Array Tool

DONG Yong,GUO Haimin,Ll Mengxia,SHl Xinlei (First Author's Ad dress:Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,Wuhan 430100,Hubei,China;School of Information and Mathematics,Yangtze University,Jingzhou 434023,Hubei,China)

Abstract:There existed two shortcomings of multiphase flow monitoring in horizontal wells by using capacitance array tool(CAT),one was imaging distortion of CATView software,the other was the loss of oil signal in oil-water two phase flow logging.The reasons for the shortcomings are analyzed firstly,the first is that the flow pattern is not fully considered in existing imaging algorithms,the second is that the structural character is not considered in the instrument.The ideas for the improvement of flow imaging algorithm are point out,and it is proposed that stabilizer should be used when using CAT.

Key words:capacitance array tool;multiphase flow;imaging algorithm;production logging

87 Application of Isolation Scanner for Cementing Quality Evaluation for Casing Testing in Tarim Oilfield

FAN Wentong,ZHENG Xinhua,LlU Yonglin,GUO Xiuli,YUAN Shijun,Ll Jinfu (First Author's Address:Research Institute of Exploration and Development,Tarim Oilfield Company,PetroChina,Korla 841000,Xinjiang,China)

Abstract:The geologic structure of Tarim Oilfield was complex and the hydrocarbon reservoirs were buried deeply.Well drilling technology of deep and ultra-deep wells was complex and the structures of casing string were various.How to detect the casing damage and corrosion caused by well drilling or development operation became a great problem of well logging project.To solve the problem,a new generation of cementing quality evaluation tool Isolation Scanner was adopted for assessment of the casing damage.Casings detection was performed through impulse backward wave and flexural wave attenuation measurements,at the same time,the wearing,corrosion and the centering of casings were evaluated quantitatively.The operation principle and field application of Isolation Scanner in Tarim Oilfield are introduced.Case study shows that good result is obtained in application.

Key words:Isolation Scanner;casing testing;casing-damage testing;casing centering testing

92 Key Drilling Technology Based on Coal-bed Gas V-shaped Horizontal Well Group

LlU Ming,XU Xiaoshun,Ll Xufeng,LlU Wei,Ll Ye,ZHAl Wentao,Ll Peiqing (First Author's Address:Drilling Technologic Company,Shengli Petroleum Engineering Co,Ltd,SINOPEC,Dongying 257064,Shandong,China)

Abstract:Coal-bed gas V-type horizontal well group was a type of connecting well group that was composed of two horizontal wells and a vertical well.When it was connected with them,the horizontal wells were used for providing discharge channel and vertical well was for oil and gas production.It had the advantages of increasing the effective oil supply range and improving single well production.The 3-V1 Well Group that was tested at initial stage was described,and combined with field operation,the technical measures of experiences of the key drilling techniques such as well trajectory control,remote accurate connection and selection of drilling fluid were systematically denoted.The V-type horizontal well group is successfully completed,it shows that the technique can be used as one of the coal bed gas development means,it provides technical support for future large-scale development of coal bed gas in the south block of Yanchuan Area.

Key words:coal-bed gas;V-type horizontal well group;well trajectory control;remote precise connection

96 Application of?88.9mm Slim-casing Drilling and Completion Technology in Sulige Gasfield

HUANG Zhanying,ZHOU Wenjun,OUYANG Yong,WU Xuesheng,DUAN Zhifeng (First Author's Address:Research Institute of Oil and Gas Technology,Changqing Oilfield Company,PetroChina;National Engineering Laboratory for Exploration and Development of Low-permeability Oil and Gas Fields,Xi'an 710018,Shaanxi,China)

Abstract:To explore new ideas of developing effectively low permeability gasfields,Changqing Oilfield Company carried out slim-hole drilling and completion test in Sulige Gasfield.In early test,“straight well drilling for preventing inclination”using?88.9mm small drill-tool was difficult,small diameter PDC bit was poor wear resistance and high pressure was induced in slim-hole drilling,the techniques used for small casing long interval drilling was not matured for the whole well cementing,by which the application of slim-hole drilling and completion was restricted.In allusion to the problem of slim-hole drilling and completion,researches were carried out in 2011～2012 for using the technologies of pre-bending of straight well drilling with?88.9mm slim-hole drill-tool,designing of PDC bit for wear resistance,application of?101.6mm drillpipe,low density cement,one return to full hole cementing slurry and slim-hole fracturing.A technology of?88.9 mm casing no tubing drilling and completion with low cost is created.It was successfully tested in Well Su6-X-1,Well Su6-X-3,Well Su 6-X-5,by which the drilling interval is shortened for 22.7%compared with previous drillings,it reaches the index of conventional well drillings and it provides a new idea for the development of low permeability and low efficiency gasfields.

Key words:Sulige Gasfield;slim-hole well;“pre-bending”straight well for inclination prevention;PDC bit;?101.6mm drillpipe;?88.9 mm small casing cementing

101 Study and Application of Oil-based Drilling Fluids for Horizontal Well Drilling

WU Bin,WANG Jian,SHU Fuchang,XlANG Xingjin,NlE Mingshun (First Author's Ad dress:Post-doctoral Research Station of Geological Resources and Geological Engineering,Yangtze University,Jingzhou 434023,Hubei,China;Hubei Hanc New-technology Co,Ltd,Jingzhou 434000,Hubei,China)

Abstract:Based on the characteristics of horizontal well drilling in shale oil and gas reservoirs,sand carrying capacity and sealing ability of oil-based drilling fluid were emphatically studied.And an oil-based drilling fluid system for horizontal wells in shale oil and gas reservoirs was established.The result of its field applications in four wells shows that the oil-based drilling fluid has good stability and rheological behavior without cuttings beds,it has good anti-sloughing ability and low filtration and successful electrical logging is successful at the first time.Casing is set smoothly.

Key words:oil-based drilling fluid;shale oil and gas;horizontal well;increase yield point;wellbore cleaning ability; wellbore sealing ability

105 Study on Cement Slurry Completion for Slim-hole and Single-channel Wells

JlN Yong,XU Mingbiao,WANG Xiaoliang (First Author's Address:School of Petroleum Engineering,Yangtze University, Wuhan 430100,Hubei,China)

Abstract:The slim-hole drilling technology was combined with single-channel well technology for technology of slimhole and single-channel well drilling,higher requirements for the cement slurry and security in cementing were put forward due to the characteristics of small annular clearance and only one channel of oil tubing.Through laboratory comparison and study,a low viscosity polymer cement slurry system using Class D cement is put forward according to the characteristics of slim-hole and single-channel well cementing.The slurry system has a good rheological properties, small fluid loss,zero free water,good stability,adjustable density and thickening time,good toughness and good safety performance.It can satisfy the requirements on cement slurry for slim-hole and single-channel well cementing,it has good prospects of application.

Key words:slim-hole;single-channel well;well cementing;slurry

110 Research of Drilling Risk Evaluation and Measures in the Piedmont Region of Kuqa Depression

ZHU Liang,ZHONG Wenjian,LlU Xiaomin (First Author's Address:School of Petroleum Engineering,Yangtze University,Wuhan 430100,Hubei,China)

Abstract:With the development of continuously drilling in deep complex formation,it was more and more difficult to control the risk in drilling process.Based on the analysis of drilling engineering characteristics,the risks of drilling in piedmont region of Kuqa depression were evaluated,it was considered that the risks were mainly from the factors of borehole instability,salt gypsum rock,bit performance and so on.Through the determination of safe drilling fluid density window in the piedmont region of Kuqa Depression,the evaluation of drilling fluid system,the analysis of salt gypsum rock characteristics and bit performance,measures are given to ensure the safe drilling in the piedmont region of Kuqa Depression.It has great significance for avoiding the risk of drilling and effectively formulating safety drilling technology scheme in piedmont region of Kuqa Depression.

Key words:drilling risk;drilling safety;piedmont region;Kuqa Depression

114 The Effect of Heterogeneity Characterization on Water-out Rules in Fluvial Reservoir

NlNG Bo,JlA Ailin,PENG Huanhuan,JlANG Junchao,LlU Hui,XU Jiafeng (First Author's Address:Ordos Branch of Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China)

Abstract:In fluvial reservoirs plane and vertical changes were faster.The intralayer heterogeneity characteristics of fluvial reservoir severely affected the vertical water-out rules.Based on the fine numerical model,the effect of water out characterization on rhythm,sandwich distribution and well pattern on water-out rules were quantified.The test and simulation results show that the water-out level can reach 15%～60%under different reservoir conditions.There is a big influence on water-out rules for different vertical simulation thickness with the biggest relative error of 120%,especially for reverse rhythm reservoir,the vertical simulation thickness should be smaller than 0.4m in funnel sandwich region.The research result provides a theoretical reference for determining production index and production plan for oilfield development.

Key words:fluvial reservoir;intralayer heterogeneity;internal reservoir rhythm;characteristics of interbed distribution;injection-production well pattern;water-out rules;fine numerical simulation

120 Design of Overall Development Using Cluster Well in Mountain Areas

CHEN Huailong,WANG Zhaofeng,SUN Lin,LlU Cuifeng,TANG Zichang,Ll Zhengzhong (First Author's Address: CNPC International Limited(Afghanistan),Beijing 100724,China)

Abstract:K Oilfield was located in the north of Afghanistan,where surface was a hilled one,it was rugged locally with relative height difference of 300～500m,road condition was poor,it was very difficult for drilling,workover and sur-

face facilities operation,and operation cost was high,therefore principle of overall development using cluster wells was setup.A math model for overall optimized design for development using cluster wells is established by using math program optimization method.The correlation between number of platforms of cluster wells and drilling penetration is derived,the factors of penetration,number of newly built platforms,platform size and investment are integrally taken into consideration.Eventually the overall program of cluster well locations in K Oilfield is established.

Key words:cluster well;well pattern design;optimized design

124 Influence of Reservoir Dip and Rhythm on Force Applied Condition of Remaining Oil Droplet at Ultrahigh Water-cut Stage

Ll Jindan,LlU Haohan,LlU Zhibin,YAN Yongqin (First Author's Address:Sichuan College of Architectural Technology, Deyang 618000,Sichuan,China)

Abstract:At present,most onshore oilfields in China have entered into high or ultra-high water-cut stage,but the recovery percent has been low.In general,the remaining oil saturation was higher than the residual oil saturation,and the enrichment region of remaining oil still existed.The influence of reservoir dip and rhythm on the force applied condition of the remaining oil droplet at ultra-high water-cut stage was great significance for further enhancing oil recovery and stabilizing oil production.The remaining oil at ultra-high water-cut stage was dispergated in capillary and the effect of micro-factors on remaining oil distribution was apparent.The remaining oil droplets in ultra-high water cut stage are used as object to analyze the effect of reservoir dip and rhythm on force applied condition of and force applied equations of the remaining oil droplet are established considering the reservoir dip and rhythm.This study provides a basis for studying micro filtration mechanism at ultra-high water cut stage.

Key words:ultra-high water-cut stage;reservoir dip;rhythm;force applied condition

128 Composite Well Test Model Based on Oil-water Two Phase Flow for Injection Wells

Liu Jiajie,MENG Yingfeng,Ll Gao,WEl Na,Bl Bo,Ll Wenzheng (First Author's Address:State Key Laboratory of Reservoir Geology and Exploration,Southwest Petroleum University,Chengdu 610500,Sichuan,China)

Abstract:At present,well test on water injection wells was based on single phase filtration theory and without considering the parameters of water content and water advance front and the effect of fluid and its property changes on pressure curve were not analyzed.A composite well test model was established for water injection wells based on law of conservation of mass and uniformed relative permeability curve for core in water injection wells and oil-water two phase flow filtration theory.The model was inverted by Laplace transformation to get the Laplace space solution;then,real space solution was obtained by using Stehfest numerical inversion;a typical curve of pressure-pressure derivative was drawn.The influence of the parameters such as water advance front,oil-water advance front,water content and water saturation on well test curves was analyzed,the effect of fluid property and formation changes on the variation of well test curves were discussed.The study results are significance for understanding physical parameters and water injection situation in water injection reservoir,it provides basis for further and rational development in water injection reservoirs.

Key words:oil-water two phase flow;well test analysis;water advance front;water content;water saturation

133 Application of Segment Flow Measurement Technology in Horizontal Wells

LlU Huaizhu,Ll Liangchuan,Ll Cheyu,WU Jun (First Author's Ad dress:Research Institute of Drilling&Production Technology,Jidong Oilfield Company,PetroChina,Tangshan 063004,Hebei,China)

Abstract:Horizontal wells were often used for oil development in the onshore fault block reservoirs in Nanpu Area of Jidong Oilfield.During the horizontal well development,edge water and bottom water channeling,water-out were easily induced,water content was raised rapidly,by which oil productivity decrease was caused,and the effect of oil development was severely influenced.It was needed to test the producing profile and water-out conditions of horizontal wells to take effective measures in time,reduce the water content,tap the potential of residual oil and enhance oil production of single well and ultimate oil recovery.Therefore segment flow measurement technology was studied by using logging instrument carried by drawing device for testing the producing profile of horizontal wells.The technology is by used in 4 horizontal wells with high water-cut,and complete test data are achieved.It provides effective test meanings for solving problem of high water-cut in horizontal wells.

Key words:horizontal well;production profile;drawing device;gas lift;high water-cut

136 Technologic Research on Air Injection to Improve Oil Recovery in Block Leng 35

GAO Rui,SONG Kaoping (First Author's Address:School of Petroleum Engineering,Northeast Petroleum University, Daqing 163318,Heilongjiang,China)

Abstract:The Block Leng 35 in ultra low permeability reservoir had the basic conditions for implementation of air injection to improve oil recovery technology and potential of oil production.Under the condition of experiment,the best gas injection rate was 0.3m L/min,and the recovery efficiency increased by 7.2%based on water flooding.Under the reservoir condition,a proper gas injection rate was 0.65PV,the recovery rate could be raised by 8.15%.the At late air injection period,final recovery rate was low,so development method should be transformed as soon as possible.And water alternating gas injection method could significantly improve oil recovery rate.The experimental result provides effective technical support for field production.

Key words:ultra low permeability reservoir;air injection;recovery rate;the time of injection;injection mode

139 Blocking Removal Technique Used in Well A5 of Lyuda 10-1 Oilfield

ZHAO Yingqiu,JlN Xiaoxia,WU Wei,WU Bo (First Author's Address:CNOOC Tianjin Chemical Research&Design Institute,Tianjin 300131,China)

Abstract:The blocking of polymer was increasingly serious in Well A5 of LD10-1 Oilfield,so various chemical analysis methods were used for analyzing the compositions of scaling samples in the oilfield.In consideration of the characters of the stemming,a new composite technique was developed for blocking removal,a dissolution test for scaling sample for the composite blocking removal technique and simulation test for the blocking removal were evaluated.The results show

that the composite blocking removal technique can be used to reduce the polymer blocking in the wells,restore permeability and water absorbing ability in formation.In December 2011,a field test for blockage removal was carried out in Well A5.The fluid adsorption capacity in the target zone increases from 502m3/d to 800m3/d,a remarkable blocking removal result is obtained.

Key words:LD10-1 Oilfield;polymer injection well;blocking removal;water absorbing capacity

143 Performance of Foam System Composed of Different Phases of CO2

PEl Hui,ZHANG Zanwu (First Author's Ad dress:Department of Scheduling and Planning,Zhongyuan Oilfield Company, SINOPEC,Puyang 457001,Henan,China)

Abstract:CO2had three different states such as gaseous,liquid and supercritical states,the exterior feature and stability were different for foam produced by different phases of CO2.Via high temperature and high pressure foam instrument the gaseous,liquid and supercritical states of CO2foam were studied.Experimental results show that the shape of foam formed by supercritical CO2is between the emulsion of gaseous CO2and liquid CO2.With the increase of temperature, its foaming volume and semi-attenuation period reduce.With the increase of pressure,its foaming ability and foam stability are obviously raised especially under supercritical condition.In foam sealing experiment,the drag coefficient of foam created by supercritical CO2is higher than that of gaseous and liquid CO2.

Key words:CO2foam;supercritical condition;phase,visualized foam meter

146 The Technical Research and Application of Inspecting Seal Ability by Tracer

WANG Diju (Author's Address:Exploration and Development Center in Xinjiang,Henan Oilfield Company,SINOPEC,Yanqi 841100,Xinjiang,China)

Abstract:Based on idea of sealing ability inspection using tracer,tracer selection and its dosage,its sampling and check,a technical study was carried out on sealing ability inspection using tracer,a method for sealing ability inspection using tracer was created innovatively.The method was easy operation,safety coefficient was high with low cost,without pollution and no accounting for production by operations,high success rate of inspecting seal ability,it had more reliability of the technology.The method is used in 32 wells,there are 3 wells of seal failure and it is successfully used in 29 wells,the success rate is 100%.The method of inspecting seal ability by tracer provides a new basis for judging seal reliability of packer,it further enhances the effect of seal ability inspection,and beneficial for promoting the understanding of reservoirs to reduce blind operation of wells.

Key words:water plugging;inspecting seal ability;tracer;potassium sulfocyanate

149 Field Practice and Analysis of MEOR in Shengli Oilfield

SUN Sangdun (Author's Address:Institute of Oil Production Technology,Shengli Oilfield Company,SINOPEC,Dongying 257000,Shandong,China)

Abstract:Microbial enhanced oil recovery(MEOR)was a new technology of EOR which has been carried out in Shengli Oilfield from 1995,it has been used for field test in 7 blocks successively in different ways.The experiences of its field selection and development of field operation in Shengli Oilfield were summed up.The operation effect obtained in the 7 blocks was emphatically analyzed,the cumulated oil increment was 17.2×104t.Practice proves that MEOR can be used to further enhance oil recovery based on waterflooding and even after polymer flooding.The main influential factors of field operation of MEOR include reservoir temperature and its heterogeneity.The technique of MEOR has the features of long efficiency of displacement,good comprehensive benefit.To further improve its field operation efficiency,the techniques of numerical simulation of MEOR and its matched technologies should be emphasized in the future.

Key words:microbial enhanced oil recovery(MEOR);block selection;operation process;affecting factor

153 Experimental Study of A New Polymerized Blocking Agent in Formation

LlU Xiang,WANG Yonghe,WANG Jiaxiang (First Author's Address:College of Chemistry and Chemical Engineering, Xi'an Shiyou University,Xi'an 710065,Shaanxi,China)

Abstract:In the development of oilfield,to seal the reservoirs with high permeability,big pore path,fractures and enhance oil recovery ratio of waterflooding,the commonly used method was water plugging by chemical ways.The underground copolymerization crosslinking water plugging system was studied,which was composed of acrylamide,2-acrylamide-methallyl sulfonate,acrylic acid,crosslinker,ammonium persulfate and polyacrylamide.The factors influencing the polymerization reaction were discussed,the polymerizable gel property was evaluated.The results show that the gelling strength is strong,it has good property of adsorption and expansion and good salt resistance,good sealing and water plugging effect.

Key words:water plugging agent;polymerizable gel;acrylamide;water plugging

157 Research of Dispersion Time of HG Drag Reduction Agent(DRA)in Pipelines

LlU Sheng,CAO Danfu,WU Jie (First Author's Ad dress:South Branch of Sinopec Sales,SINOPEC,Guangzhou 510620,Guangdong,China)

Abstract:DRA was a kind of special chemical agent used in oil pipelines.This study used C6～C16of alpha olefin monomer,bulk polymerization was a HG drag reducing polymer with viscosity average molecular weight greater than 300× 104.Field test shows that drag reduction agent could not react in the whole pipe section,it only reacted in dispersed pipe for drag reduction and oil increment.The effect of DRA was closely related with the dispersion time,different media had different dispersion times.The dispersion time to transport Oman crude oil in Linpu Pipeline,transport diesel and gasoline in Lou-meng Pipeline were 240,60 and 40min respectively.In practical application,it is needed to fully consider the effect of dispersion time on the drag reduction agent.When necessary,the dispersing time can be reduced for improving the efficiency of drag reduction agent,it is especially important for the wharf of fast oil loading and unloading of a short distance pipeline.

Key words:drag reduction agent;dispersing time;drag reduction and oil increment;oil pipeline