ABSTRACTS

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05CretaceousTugulugroupbottomsedimentsandunconformitycharacteristicsofChepaiziuplift,JunggarBasin

Zhu Feng et al(Petroleum Engineering Geophysical Southwest Company, SINOPEC, Deyang 618000)

Situated in the northwestern margin of the Junggar Basin, Chepaizi uplift is an important secondary tectonic unit. Tectonic movement of Cretaceous sediments was mainly controlled by late Jurassic Yanshan Ⅱ curtain. By analyzing sedimentary characteristics of Tugulu group bottom, combined with geophysical, coring and logging data, the studies believe Cretaceous Tugulu group overlapping (angular unconformity) is deposited on top of bedrock under the Carboniferous system, with low angle unconformity surface, developed alluvial fan-fan delta-lacustrine depositional system and big residual thickness variance. The sediments are mainly of black-gray, green-gray breccias and boulder-clay. The gravel is mainly composed of igneous breccias. According to the datum (lake level) is located below the surface of the basin slope break period, residual alluvial fan roots fan channel fill, it can be classified as low-level alluvial fan depositional model.

Keywords:Junggar basin; Chepaizi uplift; Tugulu group bottom; Alluvial fan; Unconformity surface; Depositional model

09Studyonpre-JurassicpalaeogeomorphologyreconstructionofHuanjiangregion,OrdosBasin

Liu Ruidong et al(Earth Science and Engineering, Xi'an Petroleum University, Xi'an 710065)

As sedimentary development and hydrocarbon enrichment regularity of middle-lower Jurassic series was controlled by Pre-Jurassic palaeogeomorphology, it is of great importance to accurately reconstruct and depict the ancient topography. By taking Huanjiang region of Ordos Basin for example, through a large number of studies on ancient geology, sedimentary facies and palaeogeography, and ancient flow direction, a clear background of Jurassic sedimentary deposition before the tectonic framework and provenance direction has been made. Combined with a large number of logs and core data, the study on Yan-10+Fuxian study sedimentary thickness has been carried out. By using sediment thickness impression method, pre-Jurassic palaeogeomorphology was restored. Pre-Jurassic palaeogeomorphology reconstruction of Huanjiang region, Ordos Basin presents west-high and east-low, into the highlands erosion area, slope and residual hill, valley and river between the ancient mound. Pre-Jurassic palaeogeomorphology was the major factor controlling sedimentary facies distribution and reservoir distribution of Fuxian and Yan'an early periods. Palaeogeomorphology slope zone is the most favorable for the formation of the reservoir.

Keywords:Ordos Basin; Huanjiang Region; Pre-Jurassic; palaeogeomorphology

12PaleozoicgasreservoirformingcharacteristicsanalysisofFuxianregioninsouthernHubei

Ma Chao et al(North China Branch of Sinopec Exploration and Development Research Institute, Zhengzhou 450006)

Through detailed analysis of the structure, source rocks, reservoir rocks, cap and other aspects of the Upper Paleozoic, the upper Paleozoic reservoirs are of good reservoir forming conditions, and the trap type is the lithologic trap. Based on the relationship between hydrocarbon source rock and lithologic traps, the combination of upper Paleozoic reservoir is divided into a source close to the type and source type categories. Combined with previous studies, the Upper Paleozoic gas reservoir model has been established. Reservoir studies indicate that the distribution of lithologic gas reservoirs Fuxian areas is mainly affected by hydrocarbon source rocks and reservoir rocks distributed control. The northeast of Fuxian region is the development zone of the source rocks and multi-laminated sand-based, and it is a favorable target for exploration evaluation.

Keywords:Ordos Basin; Fuxian region; Upper Paleozoic; reservoir characteristics; hydrocarbon accumulation mode

16OriginofoverpressureandboostermodeofbeachbarsandstoneinupperEs4formationofwesternDongyingdepression

Wang Guoqing(Western District Institute of Shengli Oilfield Company, SINOPEC,Dongying,Shandong 257001)

Beach bar sandstones are important sedimentary reservoirs in upper Es4 formation of western Dongying depression and overpressure has significant controlling effect on hydrocarbon accumulation of beach bar sandstones. By using response characteristics of logging parameters on overpressure, a discrimination method of overpressure causes has been established. Through overpressure causes analysis, it believed that rapid sedimentary burial of sand in Dongying depression is one of the important factors of overpressure. The extensive development and the thermal evolution of the four sub-segment sand source rocks makes hydrocarbon booster become another important reason for the formation of overpressure. The booster mode of western Dongying depression has been established and the overpressure evolution can be divided into three stages, namely normal compaction stage, early under-compaction hydrocarbon booster stage, and a lot of hydrocarbon generation and expulsion supercharged stage. At different stages in the overpressure development, under-compaction and hydrocarbon booster have become the most important factors.

Keywords:Dongying sag; beach bar sandstones; pressurization during hydrocarbon generation; pressurization mode

20EquilibriumdepthmethodtorestoreformationpressureduringextendingperiodofOrdosBasin

Qi Yalin et al(China Changqing Oilfield Company, Research Institute of Petroleum Exploration and Development, Xi'an 710018)

With reference to mudstone porosity microstructure research results of Chang-7 segment of Yanchang formation, by applying nuclear magnetic resonance (NMR) logging evaluation technology of pore structure, combined with petrography observation, the analysis on mudstone undercompaction porosity and pore microstructure characteristics has been carried out, and the applicability of the equilibrium depth method to restore the abnormal formation pressure during extending period of Ordos Basin has been discussed. The results show that the nuclear magnetic resonance (NMR) evaluation of pore structure, pore structure observation and quantitative analysis, the measured porosity does not support the existence of abnormal plateau intergranular pore and porosity in undercompaction of Chang-7 segment of Yanchang formation. The acoustic transit time deviated from the normal compaction trend curve, and it can't reflect the segment abnormal plateau intergranular pore and porosity, and the equilibrium depth method to calculate the maximum phase embedded depth of abnormal pressure is not applicable.

Keywords:equilibrium depth method; acoustic transit time; pore fluid pressure; extension period; Ordos Basin

23ResearchprogressofTriassicstratainYiningDepression,Xinjiang

Weng Xia et al(Petroleum Exploration and Development Research Institute of Henan Oilfield Company, Sinopec, Nanyang 473132)

On the basis of previous studies, by integrated use of rock stratigraphy, biostratigraphy principles and methods, starting from drilling and outcrop, according to new information obtained fossils, combined with lithology, tectonic movement, Yining depression Triassic rocks, the biostratigraphy has been studied for the first time. The results show that Yining depression is lack of Triassic, the introduction of the northwestern margin of the Junggar Basin system has been proposed in the area of rock formations. From bottom to up, middle Triassic Karamay group and upper Triassic Baijiantan group were developed. Yining depression Triassic fossil pollen fossils can establish two combinations, combinationsⅠ for Aratrisporites-Piceaepollenites-Chordasporites portfolio, during Middle Triassic era, the combination Ⅱ for Piceaepollenites-Dictyophyllidites -Colpetopollis portfolio, during the Late Triassic.

Keywords:Yining depression; stratigraphic division; stratigraphic correlation; Triassic

27FormationwaterchemicalcharacteristicsofXY-1wellandwatertypechangeanalysisinXiangzhongdepression

Peng Liu et al(Petroleum Exploration and Development Research Institute of East China, Sinopec, Yangzhou, Jiangsu 225007)

XY-1 well is a shale gas well of Lianyuan sag in Xiangzhong depression. During the production process, the formation water changed from calcium chloride type to sodium bicarbonate type. To find out the change reasons, through analysis of hydrocarbon preservation conditions and formation water chemical characteristics, the formation water salinity, chlorine coefficient magnesium, sodium and chlorine coefficient, desulfurization coefficient, carbonate equilibrium coefficient are small, with good hydrocarbon preservation conditions. Water-type change of formation water may be mainly affected by the injection of CO2 instead of fresh surface water.

Keywords:Xiangzhong Depression; formation water; chemical characteristics; water-type

30Studyonthereservoircharacteristicsofthesecondandthethirdsub-membersofthethirdmemberofShahejieFormationinnorthareaofGaoshangpuOilfield

Yang Jingxu et al(China Petroleum Exploration and Development Research Institute of Jidong Oilfield Company, Tangshan 063004)

In second and the third sub-members of the third member of Shahejie formation in north area of Gaoshangpu Oilfield, the oil-bearing interval is long, with big variance on reservoir characteristics. Through the cast thin sandstone core sheet and mercury, such as data analysis, carried out reservoir lithology, physical property, Research reservoir space types and pore structure and other aspects of the work. The results show that the reservoir lithology of the second and the third sub-members of the third member of Shahejie formation in north area of Gaoshangpu oilfield are mainly of lithic feldspathic sandstone, with lower compositional maturity and structure maturity, and mainly developed intragranular pores and dissolved pores, mainly with Ⅱ pore structure, namely the typical low-porosity and low-permeability reservoir. On the plane, the physical property is controlled by sedimentary facies. The vertical compaction and cementation will lead to deterioration of reservoir properties, while the secondary porosity produced by dissolution will improve reservoir properties.

Keywords:Gaoshangpu oilfield; reservoir characteristics; pore structure; influencing factors

33ReservoircharacteristicsandreservoirevaluationofLei-1segmentofHuangjiachang-LongchangstructureinsouthernSichuanprovince

Zhao Guanjun et alState Key Laboratory of "Oil and Gas Reservoir Geology and Exploitation" Chengdu University of Technology, Chengdu 610059

Based on core observation, analytical data from coring interval and log data, the comprehensive studies covering reservoir rock types, reservoir space types and reservoir properties of Lei-1 segment of Huangjiachang-Longchang structure in southern Sichuan province and the main controlling factors of reservoir development have been carried out and discussed. The reservoir classification and evaluation have been made. The results show reservoir of Lei-1 segment is mainly developed with dissolution holes, intergranular pore and micro-cracks. Affected by dissolution and dolomitization in the diagenesis, the reservoir properties were greatly improved. Reservoir of Lei-1 segment is of big-middle porosity and middle-low permeability. According to reservoir classification evaluation criteria in the area, Lei-1 segment is mainly developed with Ⅱ and Ⅲ types reservoirs, and mainly distributed in the gentle slope zone, with structural high position of 900～1300m altitude and close to the ancient high uplift.

Keywords:in southern Suchuan area; Huangjiachang-Longchang structure; Luzhou ancient uplift; Leikoupo formation; reservoir characteristics

37ReservoircharacteristicsandinfluencingfactorsanalysisofYaoyingtaioilfield

Gan Wenjun(Songyuan oil production plant of Northeast oil and gas branch company, SINOPEC, Songyuan, Jilin 131123)

Based on rock slices identification, core analysis and logging data, the study on petrologic characteristics and reservoir properties of Yaoyingtai oilfield, and the influencing factors analysis of reservoir properties have been carried out. The results showed that the reservoirs of Qingshankou formation are mainly of feldspathic sandstone, with lithology of fine sandstone and siltstone, moderate sorted, mid-poor rounded, lower sandstone compositional maturity, and mid-low structure maturity. The reservoir pore structure is complex, the heterogeneity degree is high and the largest connected pore throat is generally small. The main pores include intergranular pores, dissolution pores and micro-pores. The reservoirs belong to low-porosity ultra-low permeability and ultra-low-porosity super-low-permeability. The main influencing factors are mainly sedimentary microfacies, debris composition and structure, and diagenesis.

Keywords:Yaoyingtai oilfield; petrological characteristics; reservoir properties; influencing factors

40ReservoircharacteristicsandclassificationevaluationofChang-6formationinXunyiarea,OrdosBasin

Liu Gaohong et al(Extend oil exploration and development projects, Ltd. XUNYI headquarters, Xianyang 711300)

Chang-6 oil layer of Triassic Yanchang formation in Xunyi area of Ordos Basin is a typical low porosity and low permeability reservoir and the lithology is mainly feldspathic lithic sandstone and lithic feldspathic sandstone. The pore type is mainly residual intergranular Kong and feldspar dissolution porosity. The pore throat portfolios are mainly fine pores and pore throat fine throat, reservoir heterogeneity is strong. Reservoir properties are mainly affected by the combined effect of rock composition, sedimentary facies, pore structure and diagenesis. Chang 6 oil reservoir can be divided into class Ⅰ, Ⅱ type, Ⅲ type, Ⅳ class. Through a comprehensive evaluation, the reservoir mainly belongs to Ⅰ and Ⅱ types.

Keywords:Ordos Basin; Xunyi area; reservoir characteristics; pore structure; classification evaluation

44YanchangformationreservoirpropertiesandlowerlimitstudiesinexplorationareaofFuxian,Yanchangoilfield

Meng Xiangzhen et al(Exploration and Development Research Institute of Yanchang oilfield, Yan'an, Shanxi 7160002)

According to core, oil testing, physical property data of exploration area in Fuxian, the relationship between reservoir lithology, physical properties, oil resistance and electrical characteristics and between the four identified Yanchang reservoir properties limit have been analyzed. The results showed that Yanchang formation is of low-porosity, low and ultra-low permeability reservoirs and the reservoirs with best properties are Chang-3 reservoirs, with oil-bearing type rarely reached oil level.

Keywords:Yanchang oilfield; Yanchang formation; reservoir properties; physical lower limit

47Oil-waterlayeridentificationmethodstudyofShawanformationfromChun-10wellofChunguangoilfield

Chen Ping et al(Petroleum Exploration and Development Research Institute of Sinopec, Beijing 100083)

Based on the large number of cores, logging, oil testing and analytical testing data, the oil-water layer identification of Shawan formation from Chun-10 well in Chunguang oilfield has been studied. In order to realize qualitative identification of oil reservoirs, the four properties and logging parameters characteristics have been studied. By applying core scale logging technology, the porosity interpretation chart has been established. In combination with formulas regression, experience formula and mercury injection methods, the oil saturation more suitable for this area has been determined. On the basis of this, oil-water layer identification plate suitable for this well area has been established and it will enhance the logging interpretation accuracy of reservoir parameters.

Keywords:Chunguang oilfield; Shawan formation; "Four properties" Characteristics study; oil-water layer identification

50StudyonthinoillayerloggingidentificationmethodofQilicunoilfield

Meng Xuangang et al(Qilicun oil production plant of Yanchang oilfield, Yanchang, Shaanxi 717111)

In view of the problems of Qilicun oilfield, such as low vertical resolution of conventional logs, inaccurate response to thin oil layers and thin oil leakage of reservoir interpretation, based on the influencing analysis of thin oil layers on conventional logging response characteristics, the sensitive logging curve of thin layers has been determined. Through the vertical resolution analysis of Walsh inversion method, resolution matching method and the Fourier spectrum method, the Fourier spectrum method is an effective method to improve vertical resolution. The logging curve after measurement of the Fourier spectrum method can effectively reflect the true message of the formation.

Keywords:Qilicun oilfield; thin oil layer logging; Fourier spectrum method

63LowpermeabilitycomplexfaultblocksandwestE13reservoirdevelopmentadjustmentandoptimizationstudy

Wei Jinlan et al(Petroleum exploration and Development Research Institute of Qinghai Oilfield Company, CNPC, Dunhuang, Gansu 736202)

After a long period development, sand west E31 reservoir met some prominent problems, such as high injectors-producers ratio, low recovery degree, low natural production of single well, fast decline and poor production results. In order to improve development effect, enhance the producing degree of difficult recoverable reserves, based on full argument of reservoir development potential, through the fine structure interpretation, reservoir characteristics research, the second logging interpretation and remaining oil distribution, a comprehensive adjustment program combined with infill adjustment, oil wells transferring to water wells, and oil and water wells measurements has been proposed. Through field application, good development effect has been achieved. Compared with the calibration recovery, the predicted ultimate recovery can increase 2.3 percentage points.

Keywords:sand west E31 reservoir; complex fault block reservoirs; development strategies; remaining oil distribution

66ApplicationoflateralaccretioninterlayerstudyinfluvialedgewaterreservoirsofBohaiSea

Wang Wei et al(Tianjin branch company co., LTD., CNOOC (China), Tanggu, Tianjin 300452)

Lateral accretion interlayer is an important seepage barrier of meandering river fluvial point bar inside and the meticulous depiction of the lateral accretion interlayer distribution can more effectively in guiding the development adjustments. By taking typical fluvial Caofeidian 11-1 oilfield of Bohai Sea as an example, guided by deposition patterns and meandering river deposition theory, based on combined well-seismic data and production performance, the distribution patterns and distribution range of the lateral accretion interlayer from the edge water reservoir Lm943, and their control effect on remaining oil have been analyzed. Besides, the movement regularity of underground fluids has been explained and it lays a good foundation for further remaining oil tapping work.

Keywords:Caofeidian 11-1 oilfield; fluvial; edge water reservoir; remaining oil distribution; lateral accretion interlayer

72ApplicationofcapillarypressurecurveinburiedhillreservoirtypeclassificationofJZSoilfield

Song Hongliang et al(Tianjin branch company co., LTD., CNOOC (China), Tanggu, Tianjin 300452)

Through investigation and research, combined with metamorphic buried hill oil reservoir characteristics of JZS oilfield, buried hill reservoir type classification has been proposed. According to the percolation characteristics of reservoir space reflected by the capillary pressure curve, and through calculation, the buried hill reservoir type of JZS oilfield has been determined, namely pore-fractured type. The application results show the method is simple and reliable, and it can provide guidance for field development well choose and for well pattern deployment.

Keywords:JZS oilfield; capillary pressure curve; reservoir type

78Oilsteamratioevaluationchartformulationofthermalrecoveryanditsapplication

Ye Feng((Exploration and development research institute of Liaohe oilfield company, CNPC, Panjin, Liaoning 124010)

on the basis of injection-production characteristic curves of heavy oil thermal recovery, by considering the statistical regularity between water drive reservoir geological reserves and water drive characteristic curve coefficients, the oil steam ratio evaluation chart under different recovery conditions has been established. The examples application results show the oil steam ratio chart can be effectively applied to the oil steam injection development and recovery evaluation under different stages. Meantime, it further broadens the application range of injection-production characteristics curve.

Keywords:thermal recovery of heavy oil; injection-production characteristics curve; steam oil ratio; recovery

87Anewforecastmethodofthermalrecoveryadaptabilityinoffshoreheavyoilreservoirswithbottomwater

Zhang Fengyi et al(Bohai Petroleum Institute of Tianjin Branch Company, CNOOC (China) Tanggu, Tianjin 300452)

Based on reservoir parameters of Bohai heavy oil reservoir with bottom water, the mechanism model has been established. By using numerical simulation methods, the impacts of water multiples, the reservoir thickness, oil viscosity, permeability, Kv/Kh, heterogeneity on steam stimulation have been analyzed. With the gray correlation method, a multivariate sensitivity analysis has been carried out. Besides that, through multiple regressions, the recovery calculation formula of heavy oil reservoir with bottom water has been established. Taking the comprehensive consideration of various factors affecting the steam stimulation into account, the fitting formula has been applied to predict the actual recovery of Bohai. The results indicate the method is simple, easy to implement and has a high accuracy.

Keywords:Bohai Oilfield; bottom water heavy oil; steam stimulation; sensitivity analysis

90PoretypeandporestructurecharacteristicsofcarbonatereservoirsinJinhudepression,Subeibasin

Dong Xinxiu et al(Petroleum engineering of Yanshan University, Qinhuangdao, Hebei 066004)

Based on the core observation, according to cast thin, mercury injection and other information, the subdivision of Carbonate rock types and the studies of the its pore type, pore structure characteristics and influencing factors have been carried out. The study results indicate the study area is mainly of bioclastic limestone and oolitic limestone, with developed dissolved pores, uneven distribution of pore throats. Locally the pores are better reservoir segment, presenting honeycomb or tubular. In other parts, the lithology is dense, with small porosity and fine throat, being of poor connectivity. Therefore, lithology, sedimentary environment and diagenesis are the main factors affecting the pore structure.

Keywords:Subei Basin; Jinhu depression; pore structure; pore types

95PorestructurecharacteristicsanalysisofglutenitereservoirinHailaeroilfield

Gan Junqi et al(Petroleum exploration and development research institute, CNPC, Beijing 100083)

Based on the experimental data of core properties and mercury curve, the pore structure study of Glutenite reservoirs in Hailar oilfield has been carried out. The results indicate the glutenite reservoir properties vary greatly and the correlation between porosity and permeability is poor. The pore throat radius distribution is bimodal based; the permeability and average pore radius has a better power function. The logarithmic and sorting permeability logarithmic factor characteristic structural parameters are of good linear relationship, the displacement pressure and permeability has a double logarithmic linear relationship, a linear relationship with the sorting coefficient. The retreat mercury efficiency and permeability has power function, and a linear relationship with the sorting coefficients.

Keywords:Hailar oilfield; glutenite; storage reservoir; pore structure

98WaterfloodedlayeridentificationandevaluationtechnologyresearchofNanpusag

Ma Yuejiao et al(Petroleum exploration and development research institute of Jidong oilfield, Tangshan, Hebei, 063004)

Based on experimental analysis of geochemical drilling coring in water flooded reservoirs, the geochemical properties and the reservoir parameters flooded characteristics have been made clear. Through parameters modeling of oil saturation, saturated hydrocarbon gas chromatography total peak area under two reservoir types of different water-flooded degree, the layer identification methods and evaluation criteria have been established, and a set of qualitative and quantitative calculation of the organic combination has been formed. Using this method, flooded layer evaluation of Nanpu Sag has been carried out. The results show that the water flooded degree of 7 wells in Nanpu sag coincide with the actual test oil wells flooded. The method is proved to be of strong adaptability and can provide a strong technical support for water flooded degree identification and evaluation in deep water injection development.

Keywords:Nanpu Sag; flooded layer identification; geochemical logging; gas chromatography; Pyrolysis chromatography

106Numericalsimulationstudyofheavyoilreservoirsteamfloodinginfluencingfactors-bytakingQi-40steamfloodingasaexample

Liu Weiwei et al(Jidong oilfield branch company, CNPC, Tangshan, Hebei 063004)

By taking steam stimulation of Qi-40 block as an example, by applying CMG numerical simulation software, the base model of steam drive has been established, and the impacts of various factors on development effects have been analyzed. The results indicate with the gradual increase of the positive rhythm reservoir permeability coefficient, the recovery degree and oil-steam ratio increase. When the permeability coefficient of variation is over 0.7, the recovery degree and the oil-steam ratio decrease. With the gradual increase of the positive rhythm reservoir permeability coefficient, the recovery degree and oil-steam ratio decrease. At the steam breakthrough, with the increases of dip angle, the recovery degree decreases, with the increases of the barrier thickness, the recovery degree and oil-steam ratio decrease. Regardless of whether there is the compartment or not, then development effect is the best when 1/3 position has been shot. When the plane permeability anisotropy is stronger, the development effect is poorer. When the steam injection stratified series are more, the development effects are better.

Keywords:Qi-40 block; steam flooding; numerical simulation; development effects

113CombustionassistedgravitydrainagetechnologyexplorationandpracticeofLiaoheheavyoilreservoirs

Wang Haisheng(Liaohe Oilfield Company, CNPC, Panjin, Liaoning 124010)

In order to improve heavy oil development effects of Liaohe oilfield, based on S block of Dalinghe oil reservoir, the technical feasibility of the combustion assisted gravity drainage has been analyzed. By using physical model, numerical model, reservoir engineering methods and etc, the develop parameters have been designed and optimized. According to the design results, 5 test well groups have been deployed. At present, the first well group with combustion assisted gravity drainage has been successfully ignited and has achieved preliminary effects.

Keywords:heavy oil development; combustion assisted gravity drainage; Dalinghe reservoir

119SlimholemultistagefracturingtechnologyresearchandapplicationofhorizontalwellsinwesternSichuanarea

Cao Xuejun et al(Down-hole Operation Branch of Southwest Petroleum Engineering Company, Sinopec, Deyang, Sichuan 618000)

Horizontal well multistage fracturing technology is an effective means to improve single well productivity and overall recovery degree of tight sandstone gas reservoirs. Horizontal wells of tight sandstone gas reservoirs in western Sichuan are characterized by slim holes, big displacement-TVD ratio, great difficulties in running fracturing string and limited fracturing stages, and therefore, there are great difficulties in the implementation of large-scale multi-stage fracturing of horizontal wells. By improving the casing packer structure and optimizing the fracturing string, the running of string into the wellbore is smooth and the perforated manner and multi-level multi-seam fracturing parameters have been optimized. The application of the multi-stage horizontal well fracturing technology can increase the fracturing series, and ensure the smooth implementation of large-scale multistage fracturing of casing horizontal wells in western Sichuan.

Keywords:western Sichuan area; horizontal well fracturing; string structure

133DeepboreholeinstabilityreasonsanalysisandcountermeasuresofBinhaioilfield,Dagang

Xu Jingguo et al(No.3 drilling engineering company of Bohai drilling engineering company, CNPC, Dagang, Tianjin 300280)

During the drilling process of deep holes in Binhai oilfield, the wellbore instability phenomenon occurred in several wells and therefore, the analysis of wellbore instability reasons has been carried out. Through studies on deep stratigraphic mineral composition, physical and chemical properties of shale, the regional distribution of the stress intensity and other items of rock mechanics, the main reason of wellbore instability is mainly due to the high content of clay minerals, prone to water on behalf of scores and swelling eye. Through performance measurement and evaluation of drilling fluid system on the field site, the BH-KSM potassium polymer drilling fluid system was formulated, and the fluid system can meet the borehole stability requirements of deep wells in Binhai oilfield.

Keywords:Binhai oilfield; wellbore instability; rock mechanics; potassium-based polymer drilling fluid

146PredominantchannelrecognitiontechnologyofE1f1reservoirinCH2block

Li Xiaonan et al(Geological Science Research Institute of Jiangsu Oilfield Company, SINOPEC, Yangzhou, Jiangsu 225009)

After entering high water cut development stage, CH2 block met the problems of developed predominant channel on the plane and vertical monolayer dart, which would lead to water flooded of some oil wells and fast rising of water cut. Therefore, the predominant channel recognition technology of E1f1 reservoir in CH2 block has been carried out. By using fuzzy comprehensive evaluation method, through moisture index characteristics study, the predominant channel is mainly pore type. The dynamic monitoring data and tracer test results show that on the plane the predominant channel is focused on the middle of the reservoir, and there are different predominant channels vertically at different layers. According to different methods, the pore throat radius range of the predominant channel is calculated to be between 6.0 ～ 12.5μm.

Keywords:CH2 block; predominant channel; moisture index; pore throat radius