, Volume 31 Issue 3
    

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    专家论坛
  • Two key technologies about exploration of stratigraphic/lithological reservoirs
    JIA Chengzao; ZHAO Wenzhi; ZOU Caineng; LI Ming; CHI Yingliu; YAO Fengchang; ZHENG Xiaodong; LIU Xiao and YIN Jifeng
    , 2004, 31(3): 820-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Stratigraphic/lithologic traps play a very important role in reserves and production increase in Chinese onshore exploration. It is practically proved that the key exploration technologies are reservoir prediction and sequence stratigraphy. Generally, reservoir predicting technologies can be classified as: recurrence inversion, logging restriction inversion and pre-stack inversion, which should be fit to some conditions in application. To raise vertical resolution, reservoir feature reconstruction is an effective method and seismic attribution interpretation is also very important. The application of sequence stratigraphy is affected by marine sequence framework in Chinese petroleum plays. In the past several decades, continental sequence stratigraphy didn't industrialize through the combination of outcrop, drilling and logging. So six industrialization steps for sequence stratigraphy could be effectively presented in practical exploration.
  • Prospecting and evaluation on the comprehensive geophysics studies of reservoirs in the Shengli Oilfield
    LI Yang
    , 2004, 31(3): 821-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Seismic exploration with 3D seismic as the main technology has made it a relatively high-resolution technology after many years development. However, the development of oil and gas reservoirs, especially, the kind of fault block reservoir of non-marine facies, which is a worldwide problem, has provide a tremendous challenge for geophysical technology, meaning that the development of comprehensive reservoir geophysics containing petro-physics, special seismic method, special seismic data processing method are needed. The present status and developing trend of reservoir geophysics world widely suggest that two problems related to development seismic should be solved in the Shengli Oilfield, for which one is to improve seismic resolution mostly by constrained inversion of high frequency well logging data and cross-well seismic data, so to realize well to surface combined inversion. The other is to make quantitive description of reservoir and recognition of reservoir fluids by using the series of seismic and its combination with petro-physics. In the research process of reservoir geophysics technology, different technologies and disciplines must be integrated to perform the researches under the guidance of reservoir geology and by taking seismic technology as the basis.
    • 石油地质研究
  • Modeling experiments of two-phase structural evolution in the Liaohe Depression,Paleogene
    SHAN Jiazeng; ZHANG Zhanwen and XIAO Qianhua
    , 2004, 31(3): 822-0.
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    On the basis of geological model with older tensile deformation under continental rift and younger dextral strike-slip movement in the Liaohe Depression, Paleogene, modeling experiments with formation and evolution of fracture system on the seismic line 34.8 in the East sag are conducted. The results indicate that formation and evolution of normal faults are driven by older experimental stress from upwelling of the mantle and formation and evolution of reverse and normal "flower" are induced by younger structural stresses from dextral strike-slip. Two phases structural resulted in spread arrangement of complex oil gas bearing fracture system. The results might be used to explain dynamical mechanism of complex fracture system in the Liaohe Depression.
  • Formation and distribution of hydrogen sulfide bearing gas in China
    ZHU Guang-you; ZHANG Shuichang; LI Jian and JIN Qiang
    , 2004, 31(3): 823-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The hydrogen sulfide bearing gas is the important constitute of natural gas resources, while that with high H2S content is also one of the important sources of sulfur. The resources of natural gas with high H2S content are very rich in China and mainly distribute in the continental gas fields of Zhaolanzhuang and Luojia, Bohai Bay Basin, and the marine gas fields of Dukouhe, Luojiazhai, Zhongba, Weiyuan and Wolonghe. The H2S in the above gas fields, with the contents vary from 5% to 92%, mainly distribute in oil&gas areas with rich minerals of sulfate (gypsum). According to the analysis, the rich H2S in the areas are mainly generated due to TSR. Besides, in the early forming periods of Zhaolanzhuang Gas Field, there maybe exist the H2S that sourced from the deoxidization of microbe. Finally, it can be concluded that the distribution of evaporates has some controlling effects on the generation amount of H2S and its formation conditions.
  • Key factors of gas accumulation in the north belt of Kuche Depression
    FU Xiaofei; Lü Yanfang and SUN Yong-he
    , 2004, 31(3): 824-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The basic conditions of different structure gas accumulation in the north Kuche Depression suggest that the gas supply, reservoir conditions, cap quality, trap qualification and super pressure were not dominant factors of gas accumulation. The periods of hydrocarbon generation and release, period of faults action and trap shaping phase for different structures indicated that all traps had chances to capture oil or gas. Whether gas was accumulated or not during the periods, the key conditions could be gas migration, placement and mothballing. And complication of gas resource faults which not cut through the regional cap-rock is the key factor in the north Kuche Depression.
  • Strike-sliding structure traps in the Subei Basin
    QIU Xuming
    , 2004, 31(3): 825-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Structural traps are mainly fault-noses and fault blocks in the Subei Basin. The origin of the structural traps is related to the regional extension and sliding.The traps could be classified as 4 types: fault noses and block groups in sags and slopes; extension and strike-sliding blocks at both sides of a strike-sliding fault; nose-like blocks and blocks at transition part of the strike-sliding fault; and complicated blocks at zone between the two major controlling faults for extension. Strike-sliding structures are the key role for controlling the distribution of oil pools within the basin.
  • Gas migration pattern of Upper Paleozoic in the Fuxian exploration area, Ordos Basin
    WANG Guicheng; WANG Xiulin; MO Xiaoguo; ZHANG Xinjian; ZHANG Yamin; ZHANG Fangdong and YANG Liying
    , 2004, 31(3): 826-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Fuxian exploration area is located in Shanbei slope of the south Ordos Basin. The research of gas primary migration history, dynamic, direction, as well as secondary migration direction shows that the main generation of hydrocarbon was in the Late Jurassic-Early Cretaceous,and Early Paleozoic. Besides gas diffusion, the main factor of the primary migration is the abnormal pressure of the source rock with vertical direction, i.e., downward to the Ordovician weathering zone. Secondary migration is mainly to EN. Gas couldn't move further because of the slight slope and therefore the lack of dynamic for secondary migration, as well as the poor physical property and the restricted distribution of reservoir rock. This is the most promising area for gas exploration in Upper Paleozoic.
  • Formation and distribution of reservoir of Member 1 of Shahejie Formation, Wennan Oilfield
    LI Cungui; ZHAO Qingji and CHEN Ronghui
    , 2004, 31(3): 827-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The Wennan Oilfield is located at the south central uplift belt, Dongpu Sag, where the reservoir of Member 1 of Shahejie Formation is the major super-seder and it is a lithologic and lithologic-fault block. The reservoir in Member 1 of Shahejie Formation developed between source rock and halite, forming inter-bed combination of self-generate, self-storage and self-cover. The oil is mainly immature because that the most source rock of Member 1 of Shahejie Formation entered the oil-window. The sedimentary facies of Member 1 of Shahejie Formation in the Wennan Oilfield is controlled by successive sub-aqueous palaeo-uplift and the source in the SW direction, and a delta-beach-bar system was developed. Sand pinched out to palaeo-heights and the transition from sand to carbonate and halite is gradual. The reservoir of Member 1 of Shahejie Formation in the Wennan Oilfield is obviously different from those of Member 2 and 3 of Shahejie Formation, which are the major reservoirs in the whole Zhongyuan Oilfield.
  • Subtle reservoir exploration in the slope-break belt of the north Nanyang Depression
    LU Jianlin
    , 2004, 31(3): 828-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The slope-break belt is an important concept in sedimen-tology and sequence stratigraphy. The systematic studies about the slope-break belt have been promoted in the Nanyang Depression, including forming mechanism of the slope-break belt, the base types of the sequences, system tract construction mode. Inner configurations and characteristics of depositional system suggest that the petroleum exploration in the slope-break belt of the Nanyang Depression should be focused on the subtle traps controlled by the belt.
  • The Tertiary sedimentary evolution of the Qaidam Basin, Northwest China
    ZHAO Jiafan; CHEN Xiaohong and DU Yebo
    , 2004, 31(3): 829-0.
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    The Tertiary sedimentary facies distribution in the Qaidam Basin, Northwest China, is identified by using geo-statistic method,seismic facies and sedimentary facies recognition technique depending on the core, well logging and seismic data. A main sedimentary center together with multi local sedimentary centers and the sedimentary centers developed in the Lulehe Formation, in age of Peleogene, to Shizigou Formation, Neogene, and the center migrated from south to north and from west to east, where the Shizigou to Mangya area and Yiliping to Yiligou are important sedimentary centers. The sedimentary history shows it is a down-faulted basin with the boundary of thrust faults. Particular sedimentation in Qaidam Basin was caused by the activity of two groups of thrust fracture system in Kunlun Mountain north margin and Aerjin Mountain front, and the difference of paleo-structure and paleo-topography.
  • Geochemical characteristics of cherts of Lower Cambrian in the Tarim Basin and its implication for environment
    SUN Xingli; CHEN Jianfa; LIU Wenhui and WANG Darui
    , 2004, 31(3): 830-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    In marine sedimentary strata of the Tarim Basin, Northwest China, Yurtusi Formation, Lower Cambrian has been proved to be one of the main source rocks. Laminar cherts intercalated with black shale in outcrops of the Yurtusi Formation. The content of As, Sb, Hg, Ba, Sr, V, Ni, Mo and U are rich in the cherts, especially, As, Hg, Ba and U are much richer. The ratio of Ba/Sr is lower than 10×104, and U/Th ratio is greater than 1. The ∑REE of cherts are lower, with obviously negative anomaly normalized by North America Shale, in which δCe and Lan/Cen values are 0.524-0.991 and 1.112-2.934, respectively. The geochemical characteristics suggest that cherts are likely deposited with a hydrothermal origin and formed in continental margin-abyssal environment and developed with the black shale that is deposited in anoxic environment and anoxic event.
  • Reservoir and lithology of Tertiary stromatolites in the West Qaidam Basin, Northwest China
    WEN Zhifeng; ZHONG Jianhua; GUO Zeqing; LIU Yuntian; LI Yong; GAO Jianbo; XU Xiaolin and WANG Haiqiao
    , 2004, 31(3): 831-0.
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    Stromatolites are found to be abundant in the thousand-meter-thick lower member of the Ganchaigou Formation and the lower Youshashan Formation in the Ganchaigou area, west Qaidam Basin. The stromatolites range in morpholog from domical, columnar, digitate, to polygonal types. The observations based on outcrops, thin sections and casting sections of the stromatolites, using various analytical techniques including analysis of capillary pressure curve and pattern analysis of pore structures, suggest that the stromatolites are of different pore structure closely related to the typical form, and the intraparticle pores and dissolution cavities are best developed, with low primary porosity but high secondary porosity, favoring the formation of hydrocarbon reservoirs. The reef reservoirs have distinct log and seismic signatures, which help predict the distribution and development of the stromatolites reefs in the Qaidam Basin.
  • Ruthenium-ions-catalyzed oxidation of the asphaltenes of oils and oil-source correlation in the Tarim Basin
    MA Anlai; ZHANG Shuichang; ZHANG Dajiang and LU Guijun
    , 2004, 31(3): 832-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The asphaltenes in oils from the Lunnan, Tahe, Hadexun Oilfields and well TD2 were studied by Ruthenium-ions-catalyzed oxidation. The asphaltene RICO products include n-alkan acids, di-n-alkan acids, branched alkan acids, tricyclic terpan acids, hopanoic acids, steran acids and 4-methyl steran acids. The n-alkyl chain and the biomarker bounded on the asphaltene are uneasily to be biodegraded. The biomarker bounded on the asphaltene, especially sterane has similar distribution with that of the counterparts in saturated hydrocarbon. The asphaltene RICO indicates that the Middle and Upper Ordovician may be the main source rocks of the oils in Lunnan, Tahe and Hadexun Oilfields. The method of asphaltene RICO provides a new pathway for correlation of heavily biodegraded oil-source.
  • Palaeogene immature petroleum system in the Wuyang Sag, Zhoukou Depression
    KONG Fanjun and LI Yonglin
    , 2004, 31(3): 833-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The Palaeogene source rock developed in a salt lake in the Wuyang Sag is at an immature stage with rich TOC and high hydrocarbon generation, and sandstone is of middle-high porosity and permeability and favorable sealing ability. The petroleum system is of early trap and late hydrocarbon generation and accumulation. Oil and gas distribute vertically in He-2 and He-1 Member of the Hetaoyuan Formation and horizontally in the south slope zone and the north steep slope zone. Shangzhang and Duanzhuang Block should be the most favorable play targets in the sag.
  • Origin of the low-wax heavy oils in Well Shu-1, Hailaer Basin, Northeast China
    CHEN Jianping; QIN Jianzhong and ZHANG Jiguang
    , 2004, 31(3): 834-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The crude oils in the Well Shu-1, Bayanhushu Sag, Hailaer Basin, can be defined as low-wax heavy oils with a density of 0.932 g/cm3, and wax content of 6%. The oils contain about 30% saturated hydrocarbons and over 30% resin. The carbon isotopic composition of the crude oils ranges from -34‰ to -31‰. The oils are rich in isoprenoid and β-carotane hydrocarbons, showing a predominance of phytane to pristane with Pr/Ph<0.9. The steranes are characterized with high ααα-20R configuration steranes of C27, C28, C29, low ααα-20S and αββ configuration steranes, and no diasteranes. The terpanes are dominated by pentacyclic terpanes with high concentration of gammacerane, and low content of tricyclic terpanes. The information indicates that the oils in Well Shu-1 are low maturity oil, and the organic matter generated the oils is dominated by alga which is deposited in highly reductive environment with salt or hyper-saline water. The crude oils are derived from low maturity of source rocks, the Cretaceous Nantun Formation.
  • Occurrence of organic acids in asphaltene and resins
    WANG Zhansheng; WANG Peirong; LIN Renzi and CHENQi
    , 2004, 31(3): 835-0.
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    The analysis of organic acids of asphaltene and resin from three immature oils and three source rocks indicates that the amount of organic acid extracted from asphaltene is higher than that from resin of the same sample, although the content of asphaltene is less than the resins’ in general. Compare with the fatty acids of resins, the n-alkanoic acids separated from asphaltene are characterized by higher predominance of even/odd carbon number and higher ∑nC18-/∑nC19+ ratio, representing the ratio of the total amount of n-alkanoic acids with carbon number less than 18 to that of the carbon number more than 19. The organic acids of asphaltene are low content of branched acids, including isoprenoid, iso-branched and anteiso-branched. This differences between aspaltene and resin are attributed to the difference of the bound way of organic acid, suggesting that the organic acids might be protected by the reticulate structure of macromolecular of asphaltene and keep the original features such as high predominance of even/odd carbon number.
  • Diagenesis and genesis of effective sandstone reservoirs in the Sulige Gas Field
    HE Dongbo; JIA Ailin; TIAN Changbing and GUO Jianlin
    , 2004, 31(3): 836-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The He 8-Shan 1 reservoirs in the Sulige Gas Field compose basically of low permeability fluvial sandstone with the coal-bearing stratum diagenetic patterns. The strong compaction is the main reason for the low permeability and the effective reservoirs are those units with relatively high permeability. The depositional hydro-dynamics controls the structure and components of the sandstone, and then, the following diagenetic processes and porosity evolution. The coarse sandstone prove relatively high reservoir quality, with high content of hard quartzite clasts and quartz grains, which favored the preservation of primary pores and occurrence of secondary pores. The medium and fine grain sandstone are poor or none reservoirs, with high content of soft lithic fragments, which led to tight compaction, poor preservation of primary pores and poor development of secondary pores. Six lapidofacies are classified in the Gas Field. The distribution of effective sandstone can be predicted through the integrated studies of lapidofacies and sedimentary microfacies.
  • Anastomosing river sediment of the Zao 0 reservoir group in the Duanliubo Oilfield, Huanghua Depression
    JIAO Qiaoping; HOU Jiagen; XING Huagang; LIU Yali; LIU Jinbao and MAO Guoyou
    , 2004, 31(3): 837-0.
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    The Zao 0 reservoir group in the Kongyi segment of the Duanliubo Oilfield, Huanghua Depression, composes of anastomosing river sediment. According to the observation of the core and analysis of the logging data, the sedimentary characters of the anastomosing river in the Duanliubo Oilfield is studied，for which 6 main micro-facies are divided，including braided bar, braided channel, braided channel anabranch, inter-channel, natural levees and flood plain. The anastomosing river is developed relatively stable and the natural levees and flood plain are developed widely.
  • The sediment of Es3 and Es4 Member and prediction of favorable reservoir in the Wendong-Qianliyuan Area, Dongpu Depression
    LIAO Yuantao; WANG Hua; WANG Jiahao; ZHANG Shimin; CHEN Liang; YAN Detian and JIANG Shu
    , 2004, 31(3): 838-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Based on modern of sedimentology and sequence stratigraphy, and analyses of cores, logging and seismic information, four sedimentary systems are identified in the Wendong-Qianliyuan Area, including lacustrine delta system (delta, fan delta), lake system, alluvial fan and gravity flow system. The time-space evolution of Es3 and Es4 could be divided into 3 stages: Es4 (starting stage), Es34 (fast stage) and Es33-Es31 (decline stage).The study shows that the favorable reservoirs are fan delta sand body and nose structure, front sand body of fan delta and tip-out trap, sand body of lacustrine delta-front and fault-block trap, alluvial fan sand body and tip-out trap, gravity flow, shore bar and lithological trap.
    • 综合勘探开发技术
  • The application and prospect of production seismic technique in the Dongpu Depression
    Lü Xinhua and ZOU Wei
    , 2004, 31(3): 839-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The covered area of the 3D seismic in the Dongpu Depression is about 3600km2 where 3D linking is completed and 3D seismic, VSP and crosshole seismic technique are widely used. On the base of geologic feature of the Dongpu Depression, production seismic technique, such as borehole restraining seismic conversion, deep production seismic, seismic in complex structure area, borehole-ground combinating exploration test, crosshole seismic technique test, etc, are practically used and the good effectiveness have been achieved. With the developments of seismic exploration technique and hardware, production seismic technique will have a great potential and future for structure interpretation of small block, reservoir prediction, and monitor of the distribution of oil-gas-water in the process of production, reservoir fracture of reservoir production and reservoir fracture analysis.
  • New concept of exploration strategy for the oil-rich Jizhong Depression
    YI Shiwei and WANG Quan
    , 2004, 31(3): 840-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The Jizhong Depression has been explored for years, but there remains a strong imbalance in the level of understanding of various sags, zones, and formations. Despite their long history of development, some oil-rich sags still have a large quantity of residual resource in the forms of five potential play targets: undeveloped sags in the developed depression, hidden reservoir, complex fault structure, and deeply buried and small hills and some special reservoirs. Thus, the current exploration strategy should focus on the distribution of various types of reservoirs in 3D space in terms of overlapping and connecting different structure unit, zone and strata. The play should be changed from structure-controlled reservoir to hidden reservoir, from up structure belt to down structure region, from the top to the limb of structural zones, from sub-sag peripheral to sub-sag, and from single type to multiple type of reservoirs.
  • PP-Wave AVO analysis with elastic parameters
    SUN Pengyuan; SUN Jianguo and LU Xiuli
    , 2004, 31(3): 841-0.
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    Based on the approximate equation of reflection coefficient for PP wave, given by Aki & Richards, an approximate equation of reflection coefficient for PP wave, originating from the relationships among velocity, density, Lame constant and shear modulus, is presented. The new expression has a simple form, less involved parameters and explicit physical implication. The discussion on the relationship between the parameters of Δ(λρ+2μρ)/(λρ+2μρ) and Δ(2μρ)/(λρ+2μρ) and the analysis of cross-plotting for 25 different models show that two parameters satisfy a linear relation with the line slope being the twice of the inverse of the square of the P-S velocity ratio, and the intercept is the 2.25 times of Poisson's ratio contrast. The cross-plotting could be used to extract the velocity ratio of P-wave and S-wave and Poisson’s ratio contrast, as well as to discriminate and predict the variation of lithology above/below the interfaces.
  • The application of downhole seismic in driving complex fault block reservoirs
    WANG Shouchun; LI Xiaoliang; Lü Zhongfeng and HUANG Zhihua
    , 2004, 31(3): 842-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    In the high watercut stage, complex fault block reservoirs are influenced by areal, inlayer and interlayer heterogeneities. Oil remains in the reservoir and the oil-water displacement efficiency gradually decreases. The wave front can inspire ultrasonic in the reservoir and generate large amount of air bubbles in the formation fluid dissolved with natural gas to increase drive energy. Downhole seism technique can decrease oil viscosity, weaken water locking, gas blocking as well as capillary end effect in rock pores and increase crude oil mobility. Field application in Kong 1 formation, Zaoyuan Oilfield, proves that downhole seismic is an effective way to improve the waterflood efficiency, and the natural decline in the process decreased obviously. The input output ratio of the program is 1:7.58. The downhole seismic technique influences large domain and does little harm to the reservoir. The application of this technique will make complex fault block reservoir development more economic and effective.
  • Logging and geological comprehensive Internet application platform: Forward.NET
    JIN Yong; TANG Wenqing; CHEN Fuli and ZHANG Shigang
    , 2004, 31(3): 843-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Sharing and comprehensively utilizing information derived from logging, geology and reservoir should be an important technology improvement in petroleum exploration and development. Based on the improving computer network technology, the comprehensive application software network platform Forward.Net has been successfully designed and completed. The function, characters and logging geology application are presented and the information sharing and zone geology evaluation application are emphasized in the system.
    • 油田开发与油藏工程
  • Achievements of projects for crude oil development of PetroChina produced oilfield units during the "Ninth-five Years Project"
    BIE Aifang; WANG Lirong; XIA Jing; PAN Zhijian and XIE Xuquan
    , 2004, 31(3): 845-0.
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    In order to understand the achievements of the produced oilfield units' crude oil development projects during the "Ninth-five Years Project" in PetroChina, the statistics and reservoir engineering methods are used to analyze their productivity coincidence rates, major development characters' behavior and the economic index from the following levels: sub-units where the construction projects were implemented, the oil fields, and whole PetroChina. The average productivity coincidence rate was quite high; the later the project was implemented, the less its new producers' initial output was, but the production decline rate had little relation to which year the project was implemented; the later year's projects led to higher water cut levels, indicating less and less potential and effect in produced reservoirs adjusting during their middle or late life periods; the economic indexes showed that 95.2% of the whole crude oil output during 1996-2001 in these projects had brought a quite high economic profit, and that the majority of units had gotten an average investment payback period of 4.24 years, and that these projects' investment averaged 17.76×108 RMB Yuan per million tons productivity. Although challenged with great risks, the projects of oil development in the produced oilfield units which entered middle or late life periods, did achieve quite good economic returns.
  • Commercial criterion for daily output of exploratory well in the Jiyang Depression, Shengli Oilfield
    GUO Yuanling; ZHAO Leqiang and JIANG Youlu
    , 2004, 31(3): 846-0.
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    The former Industrial Criterion for daily output of exploratory well has been unsuitable for petroleum exploration at present economic situation. Corresponding commercial criterion for daily output of exploratory well should be put forward on the basis of local exploration and exploitation performance. According to the break-even theory, formula for commercial criterion was derived by way of cash flow method. Taking the Jiyang Depression as an example, influences of different parameters on the criterion were analyzed and a commercial criterion for daily output of exploratory well is proposal for different reservoirs in the Jiyang Depression. The simplified economic evaluation method can be used in the early period of reservoir exploration to preliminary analyze the exploration and exploitation feasibility.
  • A new model for production forecast of oil and gas fields
    DING Xianfeng; ZHANG Jinliang and LIU Zhi-bin
    , 2004, 31(3): 847-0.
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    Based on the characteristics of the cumulative production, and the research of previous models for production forecast, a new model for the prediction of the production rate, cumulative production rate and recoverable reserves of oil and gas fields is developed. The model could match and forecast the exploitation indexes of the oil and gas fields, and it could be simplified to Logistic model and Hu-Chen model. The applications in a gas field and an oil field of the former Soviet Union prove that the prediction of the model is very reliable.
  • A new solution and application of starting pressure gradient in ultra-low permeability reservoir
    LI Zhongxing; HAN Hongbao; CHENG Linsong; ZHANG Minglu and SHI Chengen
    , 2004, 31(3): 848-0.
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    Laboratory displacing experiments about actual starting pressure gradient were done on 25 cores with different permeability (the values range between 0.022-8.057mD, mostly lower than 1mD), from Triassic reservoir in the Changqing Oilfield. The relationship formulae between the starting pressure gradient and average permeability of stratum are regressed from the experiment and some theoretical plates showing the relationships between the starting pressure gradient and permeability are drawn in logarithmic coordinate according to the non-Darcy law considering the existence of the starting pressure gradient of single-dimension flow. The theoretical plates, obtained from the regressed relationship formulae from the experiments and those theoretical plates solving the starting pressure gradient combined with the reality of the low-permeability oilfield, would be able to present some theoretical foundations to development of low-permeability reservoir.
  • Method of establishing two-phase starting pressure curve
    ZOU Xing; WU Fan; SUN LiJuan and QIAO Guoan
    , 2004, 31(3): 849-0.
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    To research the performance of starting pressure for two-phase (oil-water or oil-gas) flow, experiments of water driving oil and gas driving oil are done on natural cores, each relative permeability is worked out, the relative starting pressure gradients are calculated according to single-phase starting pressure gradient formula, and then the oil-water and oil-gas permeability curves are derived. The two-phase starting pressure curves reveal exponential relationship between the starting pressure gradient and the saturation of the driving phase. And the relationship is damaged in the late gas driving and water driving period, which is the main reason for the rapid decrease of the displacement efficiency in the late driving stage.
  • A new way of determing reasonable productivity for condensate gas well
    WANG Junming; TANG Hai; MA Xiaoming; LEI Dengsheng and LIU Cangyun
    , 2004, 31(3): 850-0.
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    In the course of condensate reservoir development, with the decline of formation pressure, the retrograde condensate oil will be accumulated near the bottom hole, which will damage the formation permeability. The reasonable productivity is one of the most important parameters for guaranteeing the condensate gas reservoir to be developed efficiently. Based on the retrograde fluid flow theory for gas condensate system at constant temperature, considering continuous flow course from formation, bottom hole, well head to land surface, it is presented here the calculation of condensate saturation distribution and multiphase fluid flow characteristic for a condensate gas reservoir at different production rate and production time. The dynamic optimization allocation theory is presented, in which the permeability damage caused by condensate oil has been taken into account. The application in the Qianmiqiao condensate gas reservoir shows that the reasonable productivity derived by the dynamic optimization allocation is almost the same as practical productivity of the condensate gas well, suggesting that the method is reliable and applicable.
  • Layer subdivision in the late high water cut stage in the complex fault block reservoirs, Dongxin Oilfield
    WANG Shubao and NIU Shuanwen
    , 2004, 31(3): 851-0.
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    Severe interlayer interference and reserves production imbalance occur in the late high water cut stage in the complex fault block reservoirs of the Dongxin Oilfield. Parameters as permeability, the number of main layers, pay thickness, oil properties, oil-bearing area and reserves scale have great influence on layer division. According to the results of onsite statistics and reservoir simulation, the layer division criterion is presented. The layer division is routinized and standardized using the clustering analysis integrated estimation technique. Field practice shows that the presented layer division method is reliable. The production layer was adjusted according to the research result and the oil recovery was increased 3.1%.
    • 油田非注水开发
  • Laboratory research on nitrogen drive
    WANG Jinan; YUE Lu; YUAN Guangjun; ZHOU Zhilong and HOU Tianjiang
    , 2004, 31(3): 852-0.
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    A nitrogen drive laboratory test was carried out on the samples taken from the Wen 188 Block of Zhongyuan Oilfield. The slim tube test shows that although nitrogen can't be miscible with reservoir oil, the recovery efficiency is still up to 60%. An obvious methane peak in the capillary effluent after nitrogen breakthrough is a significant sign of immiscible displacement. Two long-core displacement tests show that the recovery percent of reserves is 6.35% when injected water volume is equivalent to 4% pore volume. After converting to nitrogen injection, recovery percent of reserves is 43.77% at the point of gas breakthrough. The maximum pressure differential in nitrogen drive is 0.89MPa, which is 22.7% of that in water flooding differential, suggesting that it is possible to adopt nitrogen drive in the area where water flooding is difficult to carry out. Before nitrogen breakthrough in the test, the volume of oil produced is larger than the volume of nitrogen injected. After gas breakthrough, oil is still produced because methane and intermediate components extracted still plays a role during the displacement, whereas the production drops greatly. So how to control the nitrogen breakthrough efficiently is key to the success of nitrogen drive.
  • Prediction of polymer flooding parameters by using the support vector machine
    YUE Youxi and LIU Wenlin
    , 2004, 31(3): 853-0.
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    The significant item in the evaluation of actualization effect with polymer flooding is to calculate the residual resistance coefficient based on actual observation data. The predicting model with high accuracy and applicability can not be established efficiently by conventional methods because of the influence of many affecting factors. The support vector machine method (SVM) is presented for nonlinear function approximation, and regularization principles are adopted to solve the problem to calculate the residual resistance coefficient. The actual example indicates that this method is a very efficient technique for nonlinear function approximation.
  • Micellar properties of mixed anionic surfactants
    SUN Zhibin; ZHANG Yufu; LI Caiyun; WENG Rui; YANG Puhua and LUO Yousong
    , 2004, 31(3): 854-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    On the purpose of studying the property of the micelle of mixed surfactants in chemical flooding and applying data for the prediction of chromatography of the mixed surfactants, the surface tensions of sodium dodecyl benzene sulfonate (SDBS) and tolyoxyethylene (9.5) t-octylthenol (TX-100) were measured. The effect of the temperature, concentration and type of inorganic electrolyte on the critical micelle concentration (cmc) and the interreaction parameter of the mixed surfactants were investigated. Experiment shows that the minimum surface tension value of the mixed surfactants solution lies between that of both the pure surfactants. At a same surface tension value, the concentration of the mixed surfactants of SDBS/TX-100 was lower than that of pure surfactant, suggesting that it has synergism in surface tension reduction efficiency. The results show that the mixed micelle formation property of the SDBS/TX-100 could be described by the regular solution theory (RST) in higher concentration of inorganic electrolyte. The relative reaction parameters could be influenced by the change of temperature, concentration and type of the inorganic electrolyte, and, the RST is not perfect.
  • Micellar properties of mixed anionic-nonionic surfactants
    YANG Puhua; WENG Rui; LUO Yousong; SUNZhibin; ZHANG Yufu and LI Caiyun
    , 2004, 31(3): 855-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    For studying the property of the micelle of mixed surfactants in chemical flooding and applying data for the prediction of chromatography of the mixed surfactants, the surface tensions of sodium dodecyl benzene sulfonate (SDBS)/sodium laurate (SLA) and SDBS/sodium tetradecyl benzene sulfonate (STBS) were measured. The effect of the concentration and kind of inorganic electrolyte on the critical micelle concentration (cmc) and the relative reaction parameter of the mixed surfactants were investigated. The results show that Clint's Model could describe the mixed micelle formation property of the sulfonates with different alkyl chain length under higher concentration of inorganic electrolyte but that of the mixed surfactants of sulfonate and carboxylate could be described by the regular solution theory (RST). The influence of anionic ions with different chemical valence on the cmc of the system of SDBS/STBS was different. At the same concentration of electrolyte, the cmc of the SDBS/STBS solution in basic property was not changed but that in neutral property was decreased obviously. The solution in basic property cmc was not changed with the change of solution composition but that in neutral property was changed more obviously. The relative reaction parameters of (SDBS)/(SLA) solution containing different concentration of electrolyte calculated by RST were negative. At a same surface tension value, the concentration of the mixed surfactants of SDBS/SLA was lower than that of pure surfactant, suggesting synergism in surface tension reduction efficiency.
  • The performance of STP hard-gel in deep profile controlling
    JING Guicheng; GAO Shusheng; XIONG Wei and LI Changzhong
    , 2004, 31(3): 856-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    STP profile control hard-gel is made up of polyarylamide, cross-linking agent and retardant. The gel performance experiments were conducted with man-made cores, the gelation time was 72h at 55℃, the blocking coefficient was larger than 99.9% and it was not less than 99.8% after being flushed with 50 PV injected water. The breakthrough pressure gradient was not lower than 4.45MPa/m in high-permeability cores (5.62D) and it was 3.46MPa/m in low-permeability ones (0.57D), which shows some selectivity. Three high-permeability cores and low-permeability ones were connected in tandem, respectively; both were paralleled to form the heterogeneous model. The model was saturated with oil and profile controlling experiments were carried out, in which the total water-flood recovery was 24.3% in case of that no profile control agent was injected. The first, second and third high-permeability cores were sealed in turn by using the profile control agent, the total recovery reached 46.8%, 62.2% and 69.1%, respectively, which indicated that the recovery could be further enhanced as the sealed depth increases.The application in the exploiting zone of Daqing Oilfield is apparently effective.
  • The factors influencing the wellbore temperature in heavy oil production
    SHAN Xuejun; ZHANG Shicheng; WANG Wenxiong and YU Liping
    , 2004, 31(3): 857-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    In order to choose suitable production parameters when hot fluid is circulated in heavy oilfield, it is necessary to understand the relationship between the wellbore temperature and thermophysical properties of the rock and fluid. A 2-D mathematical model is developed for the temperature calculation and the sensibility of 14 parameters influencing the wellbore temperature distribution is analyzed. The analysis shows that the inlet fluid temperature, circulating capacity, fluid production and specific heat of the rock have dominant influences on the temperature of the wellbore and output fluid. Besides, optimal injection parameters exist in the circulation of hot fluid.
    • 油藏物理
  • Starting pressure of low permeability cores by using mercury injection method
    GAO Shusheng; BIAN Chenxu and HE Shumei
    , 2004, 31(3): 858-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Experimental researches on the 32 cores from the Daqing Oilfield have been done for studying the starting pressure of the low permeability cores. The average permeability and initial pressure gradient of every core are obtained through analysis of large amount of data from the mercury injection experiments. By matching the data of gas permeability and corresponding initial pressure gradient, the relationship between the gas permeability and starting pressure gradient is derived, with which the initial pressure gradient of every core could be calculated.
  • Theoretical and experimental study of invasion influence of fresh drilling mud on oil pay resistivity
    LI Wei; YAN Weilin and BAI Jianping
    , 2004, 31(3): 859-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The invasion of fresh drilling mud usually results in low resistivity invasion profile of oil pays with higher deep detecting resistivity (Rtd) than shallow resistivity (Rts). However, Rts may be higher than Rtd, which is theoretically analyzed and modeled from core experiment. Theoretical and experimental study suggests that high resistivity invasion profile occurs when the resistivity ratio of the drilling mud to initial formation water is higher than 2.5, and low resistivity invasion occurs when the two resistivities are close under the condition of fresh drilling mud invasion. The invasion of fresh drilling mud into oil pays is dependent on the height of oil column. After invasion of fresh drilling mud, oil pays with higher oil column show on log response a larger diversity between Rtd and Rts.
    • 油层保护与改造
  • Influencing factors of reservoir sand flow in the Guan No.1 oil group, Yangsanmu Oilfield
    LU Baorong; CAI Mingjun; LIU Shuming; ZHANG Linhe and LI Biao
    , 2004, 31(3): 860-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Guan No.1 oil group of the third block, Yangsanmu Oilfield, is an unconsolidated bottom water sandstone reservoir with high permeability and viscosity. The production of most wells is affected by severe sand flow. According to onsite data and the correlation of sand production rate to oil properties, perforation extent, producing pressure drop and reservoir properties, the favorable values of the parameters controlling sand flow are derived, that is, oil density lower than 0.96g/cm3, perforation extent lower than 40%, producing pressure drop lower than 4MPa, shale content 10.5%-16% and porosity lower than 30%. Based on the above results, the production systems of 11 wells are optimized, sand flow is in control and better production performances are obtained. The sand flow of bottom water reservoir with high permeability and viscosity is mainly related to reservoir physical properties and producing pressure drop.And oil properties and perforation extent are also influencing factors.
    • 学术讨论
  • A kind of possible natural fault petroleum trap
    LUO Qun; HUANG Handong; PANG Xiongqi; BIAN Shutao; JIANG Zhenxue and CHANG Honggang
    , 2004, 31(3): 861-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    A fault oil trap could be formed in case of that it had the reservoir condition, being covered by geological body and sealed by faults. There are 4 kinds of possible fault body traps or fault body accumulations in nature, including pitch sealing, fault thinning out and faults intersection as well as slipping between strata. The Jurassic petroleum in the Well Shishen 1, Lenghu No.3 Oilfield, north Qaidm Basin, is much likely a typical feature of the pitch sealing fault body accumulation type. Because of the special geological conditions, the fault body traps have better hydrocarbon migrating and accumulating condition, however, its accumulation is easily destroyed by tectonic motions, so, this kind of accumulations are real invisible.
    • 国际交流与合作
  • Hydrocarbon migration and accumulation in the Malacca Strait Contract Area, Indonesia
    XI Fengyun; PAN Mao and ZHANG Guangya
    , 2004, 31(3): 862-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The study on the hydrocarbon migration and accumulation was finished for the purpose of understanding the exploration potential of Malacca Strait Contract Area by analyzing the generation and expulsion period of the source rock and the tectonics developmental history.Hydrocarbon mainly migrated twice in a large scale during geological history. The second hydrocarbon migration happened during the late Miocene when the source rock reached the generation and expulsion peak of hydrocarbon and was the key hydrocarbon generation period. Under the control of the tectogenesis, the hydrocarbon mainly migrated westward and only a small amount migrated eastward in the Contract Area, so the west structural zone was the main hydrocarbon accumulation belt.
  • Global survey on use of geological analogs
    Rod Sloan and S Qing Sun
    , 2004, 31(3): 863-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    A global study of the use of geological analogs has revealed key learning about how geoscientists, reservoir engineers and managers use, and misuse, analogs. Trends in how analogs are applied, where analog data are sourced, and what processes and workflows are enhanced by analogs was studied through comprehensive interviews. Two key results are: ①Two-thirds of the companies believe casting a global net to identify the highest quality analogs reduces exploration risk and improves field development decisions. One-third of the companies favor an approach of evaluating plays and field development options by looking only at nearby well, reservoir or field data；②While seismic is often a deciding factor, a significant number of geologists believed analogs provide detail and insight needed for successful exploration and field development.
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