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01 December 2006, Volume 27 Issue 6 Previous Issue    Next Issue

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Petroleum Geological Characteristics of Compresso-Shear Basin LIU Chuan-hu 2006, 27 (6):  647-653.  Abstract ( 114 )   PDF (245KB) ( 327 )   Save The basin-formed mechanism, evolution model and petroliferous geological features of compresso-shear basins in the world are analyzed. by which six aspects of the features are summarized as follows: 1) in the compresso-shear process, the sedimentary speed of basin is high, forming thicker coarse-grained clastic rocks which normally shape good petroleum reservoir; 2) the source rocks of basin tend to coming from the organic matter-enriched rocks formed in pre-compresso-shear stages, except that in intense compresso-shear process, deep water-semi deep water source rocks are possibly developed in frontal of deep depression (fore deep) of thrust belt; 3) the en echelon folds (including anticline and fault-nose structure) are generally as good oil traps; 4) the compresso-shear process is helpful to hydrocarbon accumulation; 5) it may promote the maturity and hydrocarbon-generating process of organic matter, and 6) the thrust belts in the surrounding areas of compresso-shear basin are favorable domains for petroleum concentration. References | Related Articles | Metrics

Deep Crust Structure of Songpan-Ganzi Folded Belt in Sichuan and Its Prospect for Petroleum Exploration LI Bi-ning, JIAO Yang-quan, ZHANG Jing-lian 2006, 27 (6):  655-658.  Abstract ( 98 )   PDF (306KB) ( 221 )   Save Songpan-Ganzi folded belt in Sichuan province of China is a major issue to geoscientists. In recent years, petroleum geologists pay more attention to it because of the discovery of a low velocity-high conductive layer in the deep of this folded belt by seismic depth sounding and gravity-magnetic-electric survey. The research of large igneous rock province-Ermei basalt extrusion-mantle plume shows that Songpan-Ganzi folded belt is a hopeful target for breakthrough of petroleum exploration, and the key issue is how to make well a coupling and optimization among its faults, structures, traps and reservoirs. References | Related Articles | Metrics

Correlation of Hydrocarbon Accumulation Conditions in Yin'e Basin and Erlian Basin and Selection of Favorable Prospecting Zones HAO Yin-quan, LIN Wei-dong, DONG Wei-hong, LIU Dong-zhou, XIONG Tie 2006, 27 (6):  664-666.  Abstract ( 152 )   PDF (110KB) ( 313 )   Save Yin'e and Erliang, located in China-Mongolia frontier area, are two rift basins with similar structure and sedimentary sequence, dominated by Cretaceous as a sedimentary cover. Comparison of principal reservoir-formed conditions such as source rock, hydrocarbon migration and accumulation, etc. shows that Yin'e basin is generally poorer than Erlian basin in abundance and type of source rock, hydrocarbon migration channel and petrophysical property of reservoir of Lower Cretaceous, but similar conditions appear in some sags and areas, compared with Erlian basin. Therefore, according to Erlian's exploration experience, it is suggested that the large and deep sags with depression background could be the premier prospecting areas of Yin'e basin and searching for structure-lithology complex reservoirs should be focused in the near future. References | Related Articles | Metrics

Advances in Ordovician Study of Lunnan Area in Tarim Basin LIU Jing-jiang, YUAN Yu-chun, LONG Wei-hua, HU Long-di 2006, 27 (6):  667-669.  Abstract ( 95 )   PDF (147KB) ( 223 )   Save The contact relation was unclear within the Ordovician in Lunnan area of Tarim basin due to lack of related information. Recently, some direct proofs about the unconformity have been found by drilling and in-depth geologic study in this area, showing that there exist multiple unconformities within the Ordovician among Sangtamu formation, Lianglitag formation and Tumuxiuke formation, except for the conformity contact between Yijianfang formation and Tumuxiuke formation. There might be relatively long-term stratigraphic unconformities in successive fossil assemblage zones. References | Related Articles | Metrics

Structural Evolution and Sedimentary Characteristics of Cenozoic in Qaidam Basin WANG Bu-qing 2006, 27 (6):  670-672.  Abstract ( 90 )   PDF (612KB) ( 357 )   Save The Paleogene in Qaidam basin is in stage of weak-spreading depression, dominated by fluvial-lacustrine deposit. In Ganchaigou formation of the Neogene the active mantle source rock-magma resulted in widely depressed process, occurring the largest lacustrine overflow and deposit. The multi-tectonic movements since Pliocene in this basin took place, causing the structural deformations in geometry and kinematics. It is concluded that the deposition in Qaidam basin is controlled and reconstructed by strike-slip thrust structures, thus developing such multiple sedimentary systems as fluvial, lacustrine, alluvial, pluvial and aeolian deposits. References | Related Articles | Metrics

Mechanism and Model of Hydrocarbon Accumulation in Mabei-I Trap in Northern Margin of Qaidam Basin PENG Li-cai, ZHU Si-jun, WANG Wei-xing, LI Ji-jun 2006, 27 (6):  673-676.  Abstract ( 86 )   PDF (407KB) ( 233 )   Save The evolution history, oil source, filling time and carrier system in Babei-I trap of northern margin of Qaidam basin are analyzed. It is indicated that from Late N1 to Early N2, oil generated from Middle Jurassic hydrocarbon source rocks in Gaqiu sag migrated to the shallow layer (<1 000 m) of Well Mabei-1 within Mabei-I trap and Mabei-III trap. In the period of Middle N2, the source rocks with higher maturity of Middle Jurassic in Saishiteng sag originated expulsion of hydrocarbon followed by migrating into the deep layer (>1 000 m) of Well Mabei-1. In the Late Himalayan movement, the whole Mahai swell was uplifted, featuring fixed traps and shallower reservoirs. The model of hydrocarbon accumulation in Mabei-I trap could be described as that the drape-like structure was formed on the paleo-uplift of basement in the period of Yanshan movement, the traps were evolved successively and formed by the end of Yanshan period. Also, there exist two-source and two-stage hydrocarbon accumulations in this area. References | Related Articles | Metrics

Thermal Simulating Test of Phase Behavior Characteristic of Coal-Formed Hydrocarbons of Jurassic in Tuha Basin ZHANG Wen-lin, CHEN Yi-cai, ZHANG Dai-sheng, TU Xiao-xian, WANG Jia-hui 2006, 27 (6):  678-680.  Abstract ( 70 )   PDF (136KB) ( 225 )   Save The hydrous pyrolysis simulation test for coal samples of Middle-Lower Jurassic in Tuha basin is conducted. The PVT phase state of hydrocarbon-generated products is quantitatively calculated by PR state equation in different temperatures. The analysis shows that the oil phase of hydrocarbon generation has turned into the gas phase of it, and the vitrinite reflectance (Ro) ranges from 1.2% to 1.6%, as the simulated temperature rises. References | Related Articles | Metrics

Relationship Between Datum Cycle and Reservoir Quality in Qiudong Sub-Sag, Tuha Basin LI Sen-ming, LUO Quan-sheng, GUO Lin, CAO Zhi-xiong, XU Jun-lin, ZHANG Ya-zhen 2006, 27 (6):  681-684.  Abstract ( 80 )   PDF (273KB) ( 187 )   Save The correlation of datum cycle and reservoir quality of Middle Jurassic in Qiudong sub-sag of Taibei sag in Tuha basin is made. The analysis shows that the short-term elevation of Qiudong sub-sag is of distinct control on reservoir quality. With the datum rising, the reservoir quality becomes poor; contrariwise, it becomes good. Four types of the well log response models for the short-term datum cycle of Middle Jurassic are delineated such as retrogradation-retrogradation, retrogradation-progradation, progradationretrogradation and progradation-progradation ones. Also, with the mid-term datum rising, the braided river channel sand body is thickened, the sand grain size is getting coarser, with sand-shale ratio increasing. With the mid-term datum descending or cycling, the reservoir quality is getting poorer obviously. It is pointed out that the intervals with higher quality of reservoirs are corresponding to the reservoirs at the lower datum, so in Qiudong sub-sag, the Lower J2x4 and J2s2 could be favorable target zones vertically for lithologic oil-gas exploration; while two sides of its arc belt be advantageous zones laterally of developed lithologic oil-gas reservoirs. References | Related Articles | Metrics

Distribution and Formation of Diabase Reservoir in Central Uplift of Huimin Sag LIU Su, WANG Wei-feng, SONG Quan-you 2006, 27 (6):  686-687.  Abstract ( 84 )   PDF (129KB) ( 162 )   Save The volcanic rock reservoirs commonly occurred in domestic oil-gas exploration are significant complement of sandstone and carbonate reservoirs. According to the comprehensive information of geology, drill sample, well logging and seism, etc., the intrusive body of diabase in the area of Lin-9-Lin-3 in central uplift of Huimin sag is identified, its distribution pattern is found out and the condition of the diabase reservoir formation is analyzed in detail. The result shows that the formation and distribution of the diabase body are controlled by the occurrence of Linshang fault zone; the quality of diabase reservoir is improved during the active period of the fault. The fault zone acts as main pathway for oil-gas migrating into the volcanic reservoirs during the period of hydrocarbon accumulation and plays an important part in sealing the oil-gas reservoir during the ending period of active fault. References | Related Articles | Metrics

Fault Strike and Its Significance of Plate Dynamics in Central Placanticline, Songliao Basin GONG Fa-xiong, SHAN Ye-hua, LIN Ge, LIU Shi-lin, ZHANG De-sheng 2006, 27 (6):  688-690.  Abstract ( 91 )   PDF (177KB) ( 217 )   Save In recent years, high-precise 3D seismic explorations in central placanticline uplift of Songliao basin have revealed that the strikes of faults in this area tend to gradual migrating toward the west from the lower to the upper reflecting horizons. The top reflecting horizon T2 (dating about 98.9Ma) of Quantou formation of Cretaceous can be regarded as a reference surface, below which the strikes of major faults are NNE or SN directions, parallel to the placanticline trend; above which they are NNW directions, showing difference of about 60°between them. It is believed that such a migration of strikes represents the concordant variation of in-situ maximum horizontal principal stress, which might reflect the changes of subducted velocity of oceanic crust near continental margin. Before 120 Ma, the Izanagi plate was being subducted obliquely toward the Euro-Asia continent followed by the predominating of orthogonally subduction of the oceanic crust plate, somewhat decreasing of the velocity of the plates motion. Hence, it is suggested that compared with the oblique subduction, the orthogonal subduction could play an effective role in transmitting compressive stress from the continental margin to the interior. References | Related Articles | Metrics

Sedimentary Structures of Pukou Formation of Upper Cretaceous in Huaiyin Sag, Yanfu Depression MU Rong 2006, 27 (6):  691-695.  Abstract ( 76 )   PDF (283KB) ( 246 )   Save The types and characteristics of the sedimentary facies developed in Pukou formation of Upper Cretaceous in Huaiyin sag of Yanfu depression are analyzed. It is considered that the sedimentary structures of Pukou formation in Huaiyin sag are different from those in Yanfu depression, and the new characteristics of salt rocks of over 1000 m thickness appear in this area. From studies of these characteristcs of structures, palaeontology, drilling, well logging, seismic profile, salt chemistry and lacustrine sedimentary system, it is recognized that the new characteristics occur in structures of section Pukou II and III in Huaiyin sag, and the huge thickness of salt rocks is formed by the crust salt materials upwelling along deep fracture in the form of hot bittern and entering lacustrine basin in this area. References | Related Articles | Metrics

Effect of Salt Structure Development on Sedimentary Strata—An example of Haoxian structure of central uplift belt in Dongying sag CUI Yong-gang, FAN Tao, SUN Chang-xu, SUN Yan-da, ZHANG Xiang-xiang 2006, 27 (6):  696-698.  Abstract ( 70 )   PDF (168KB) ( 190 )   Save Salt structure is a geologic body formed by flow and deformation of halite and other evaporitic rocks. About 60% petroliferous traps are associated with the salt structure in the world. This paper discusses the basic materials and dynamic source of a salt structure of central uplift in Dongying sag of Jiyang depression, Bohai Bay basin, North China, based on seismic and drilling data, and presents three stages of the salt structural development: initial development stage, development stage and steady stage. Also, the effect of the salt structure development on sedimentary strata is analyzed. It is recognized that the configuration of the salt structure is related to the corresponding geologic climate of arid at that time; the faults related to the salt structure destroys the formation of petroleum reservoir and makes the strata in this area complicated. Salt structure is not well studied in China and it should be one of focuses for petroleum exploration in the future. References | Related Articles | Metrics

Origin of Reversal of δ13C Series and Component of Biogenic Alkane Gas in Moxi Gas Field of Central Sichuan LI Deng-hua, WANG Ze-cheng, LI Jun 2006, 27 (6):  699-702.  Abstract ( 80 )   PDF (235KB) ( 265 )   Save In normal state, δ13C in biogenic alkane gas increases, while its component content decreases, with increase of the carbon numbers. In Section-1 gas pool of Leikoupo formation of Middle Triassic in Moxi gas field of central Sichuan, both of the component content andδ13C series appear reversals. This paper analyzes the possible origins such as mixed origin, biologic origin, oil-cracked origin, migrated origin and leaked origin in detail. It is believed that such reversals in the gas field are primarily resulted from leaked origin. In adjacent Weiyuan gas field such reversals are also found. The research shows that it possibly attributes to the leaked origin. References | Related Articles | Metrics

Geochemical Characteristics and Origin Classification of Crude Oil in Wangjiagang Area in Dongying Sag WANG Sheng-zhu, JIN Qiang, QIAN Ke-bing, WANG Wen-bin 2006, 27 (6):  704-707.  Abstract ( 94 )   PDF (278KB) ( 167 )   Save The correlation of geochemical characteristics of saturated hydrocarbon and aromatic hydrocarbon compounds among crude oil, oil-bearing sandstone and source rock extractive matters in the studied area is conducted. The result shows that the crude oil can be divided into four types of origins. The first type of crude oil is characterized by low density, low sulfur, high wax content, gas chromatography of saturated hydrocarbon showing single peak, m(Pr) /m(Ph) ratio ranging from 0.51 to 0.72, relative content of sterane of C29>C27>C28 showing reverse "L" shape and high maturity, reflecting the origin of higher plants, which originates from Ek2 source rock; the second type by high density, high sulfur, low wax content, single peak shape, m(Pr) /m(Ph) ratio less than 1.0, sterane content of C29>C27>C28 showing asymmetrical "V" shape, high gammacerane content and high maturity, reflecting the origin of lower aquatic organism, which originates from Es4 source rock; the third type shows dual-peak shape, sterane content of C29>C27>C28 also showing reverse "L" shape, reflecting the mixed origin of lower aquatic organism and higher terrigenous plants, which originates from Ek2 and Es4; the fourth type by biodegradation and lack of n-alkane, being an origin-mixed crude oil of Es4. The fourth types of crude oils in this area assume regular distribution spatially. References | Related Articles | Metrics

Sedimentary Environment of Carbonate Source Rocks of Middle-Upper Ordovician in Tarim Basin GAO Zhi-yong, ZHU Ru-kai, ZHANG Xing-yang 2006, 27 (6):  708-711.  Abstract ( 82 )   PDF (256KB) ( 185 )   Save The carbonate source rocks of Middle-Upper Ordovician in Tarim basin are widely distributed in different sedimentary environments at the same period such as platform margin slope, platform inner sag, continental shelf, abyssal basin, etc. According to the differences of sedimentary facies and environment, the source rock are divided into four types such as lime-mud reef in platform margin, platform inner sag, deep-water flat slope or continental shelf, abyssal basin. The lime-mud reef type is distributed in platform margin of Upper Ordovician, the remained three types are widely distributed in Cambrian-Ordovician system. The carbonate platform margin and platform inner sag margin could be recognized from analysis of sedimentary environment of the Middle-Upper Ordovician source rocks for the purpose of determination of the sedimentary environments of source rocks of platform slope, platform inner sag and continental shelf. In addition, by means of seismic profiles, the platform margin and the platform inner sag margin can be finally identified, integrated with distribution of organic reefs. It is shown that the distribution of organic reefs is of great significance in indicating the distribution of source rocks. References | Related Articles | Metrics

Well Logging Response from Filtrate-Invaded Zone in Clastic Reservoir in Tahe Oilfield LI Yan-hua, ZOU Chang-chun, LIU Chun-fang, LIU Jian-hua, MA Yong 2006, 27 (6):  712-716.  Abstract ( 71 )   PDF (275KB) ( 193 )   Save The Donghetang formation in southwestern Tahe oilfield in Xinjiang is a clastic reservoir which appears negative distinction of deep and medium resistivity between oil and water zones. The dual induction and array induction logging data from typical wells are analyzed. The factors of mud filtrate invasion are classified as static factor and dynamic factor. The mechanism of mud filtrate invasion is studied. The calculation of formation resistivities in the case of different porosity, water saturation and mixed water resistivity shows that the negative distinction of resistivity is resulted from that the increase of formation resistivity caused by high mud filtrate resistivity and poor petrophysical property is larger than the decrease of formation resistivity caused by high water saturation and poor oil-bearing property. It is concluded that oil and water layers should not judged only by difference between deep and medium resistivities or by presence of lower resistivity zone, besides, combining the difference between mud filtrate salinity and formation water salinity with petrophysical property, oil mobility, etc., should be required. References | Related Articles | Metrics

Characteristic of Hydrocarbon Inclusion and Its Geological Significance of Jurassic in Shinan Area LIAO Jian-de, CHENG Xian-sheng, LUO Li-chong, XIANG Bao-li, WU Hong-yi, BAI Xin-min 2006, 27 (6):  717-719.  Abstract ( 85 )   PDF (188KB) ( 354 )   Save Based on the research of diagenesis of Jurassic in Shinan area of Junggar basin, the analysis and correlation of the physical phase state, homogenization temperature and salinity of the fluid inclusion show that the inclusion of Toutunhe formation of Jurassic in this area could be divided into salt water inclusion, gaseous hydrocarbon inclusion, gas-liquid hydrocarbon inclusion and liquid hydrocarbon inclusion. Based on single polar and fluorescent colors of the hydrocarbon inclusion, it could be classified as three types. Integrated with the regional burial history, the inclusion formation of Toutunhe reservoir can be divided into three stages. Also, the hydrocarbon migration and evolution of Toutunhe formation are discussed in this paper. References | Related Articles | Metrics

Analysis of Water-Yielding Pattern of Thin and Bottom Water Reservoir in Luliang Oilfield, Junggar Basin TANG Fu-ping, TANG Hai, JIANG Bing-jin, SHI Guo-xin, YANG Sheng-zhen, HAN Li 2006, 27 (6):  721-723.  Abstract ( 94 )   PDF (136KB) ( 185 )   Save The theoretical study of the recovery percent vs. water cut of thin and bottom water reservoir in Luliang oilfield is based on developing its geologic and flow models, obtaining oil-thickness ratio, oil-water viscosity ratio, relative permeability curve parameter and chart of effect of bottom water coning, etc., on water-yielding pattern of the reservoir. The comprehensive research of typical wells in water-yield pattern shows that the theoretical curves are accordant with actual situation, indicating this method is applicable to analysis and prediction of water-yielding pattern in such a reservoir. References | Related Articles | Metrics

Deduction of Material Balance Equation for Gas Reservoir with High Content of H2S ZHANG Yong, CHEN Ding-zhao 2006, 27 (6):  724-725.  Abstract ( 88 )   PDF (70KB) ( 177 )   Save The material balance equation for gas reservoir has been used to determine reserves and OGIP of gas reservoir, judge its driving type and predict its production performance. The gas reservoir with high content of H2S is a special type of reservoir. Its sulfur deposition badly affects the production of such a gas reservoir. The material balance equation for common gas reservoir takes no account of the sulfur deposition, hence it is hard used to completely describe the production performance of gas reservoir with high content of H2S. This paper deduces the material balance equation with high content of H2S considering the sulfur deposition, and provides the material balance equation for the constant volume gas reservoir with high content of H2S. References | Related Articles | Metrics

A Simple Method for Determination of Gas Well Productivity TAN Zhong-guo, HAO Yu-hong 2006, 27 (6):  726-727.  Abstract ( 126 )   PDF (76KB) ( 303 )   Save Based on gas percolation mechanics theory and general binomial productivity equation, the expression of binomial coefficient A and B as function of Kh is deduced, then the observed parameters, the parameters given by gas reservoir engineering computation (especially by well test interpretation) and data from empirical analogy method are used to establish the binomial equation for solving Kh as an unknown function for the purpose of deducing the stable productivity equation for gas well, obtaining the open-flow capacity. The case study shows that this method is practical, simple and reliable for application. References | Related Articles | Metrics

A Correlation of Weak and Strong Base ASP Flooding Processes ZHAO Chang-jiu, ZHAO Qun, ME Shi-chun 2006, 27 (6):  728-729.  Abstract ( 98 )   PDF (92KB) ( 271 )   Save The alkali-surfactant-polymer (ASP) flooding is becoming the dominant recovery technology in Daqing oilfield. In order to recommend the feasible type of ASP flooding, the ASP flooding with weak base is compared with the ASP flooding with strong base. The results show that the oil recovery by the weak-base ASP flooding process is over 20% higher than water flooding process, which is comparable with that by the strong-base ASP flooding one. Both of ASP flooding processes have the same emulsion viscosity of over 100 mPa·s, but the emulsification of weak-base one is a little better than that of strong-base one. In addition, the former has the advantage of the latter in the injection-production capacity and recovery rate. In particular, the scaling tendency of the former is weaker than that of the latter, with little effect on production wells. Therefore, the ASP flooding with weak base should be selected as a candidate for the process in expanding application. References | Related Articles | Metrics

Interwell Communication in Carbonate Reservoir of Ordovician in Tahe Oilfield, Tarim Basin LV Ming-sheng, YANG Qing-jun, CHEN Kai-yuan 2006, 27 (6):  731-732.  Abstract ( 106 )   PDF (105KB) ( 260 )   Save Tahe oilfield undergone multi-stage tectonic evolution and paleo-weathering karstification belongs to a fractured-vuggy carbonate field with strong heterogeneity. To study its interwell communication or connectivity is greatly helpful to classifying the development block and further improving the development performance of Ordovician reservoir. By means of dynamic production data and Orkiszewski method for bottom hole pressure calculation, the formation conductivity is estimated and evaluated, the interwell connectivity is analyzed. The result is consistent with static geologic study. And this method, integrated with other available data, can be used to more precisely classify the connected blocks of reservoir. References | Related Articles | Metrics

Laboratory Investigation and Appraisal on Non-Alkali Binary Chemical Flooding System NIU Rui-xia, CHENG Jie-cheng, LONG Biao, LI Bo-lin, ZHANG Chang-bao 2006, 27 (6):  733-735.  Abstract ( 76 )   PDF (116KB) ( 236 )   Save The harm of alkali becomes more and more obvious with the progress of the research on the ASP flooding technology for EOR. This paper presents the home-made petroleum sulfonate NPS-2 as a surfactant, by which investigates the effects of NaCl and petroleum sulfonates of different concentrations on the oil-water interfacial tension in area of No.4 oil production plant of Daqing Oilfield Company Ltd., determines the formulation for non-alkali binary flood system and evaluates its applicable universality and displacement effectiveness. The results show that this binary formulation system (CNaCl=0.6%~1.2%, CNPS-2=0.1%~0.3%, CHPAM=0.12%) may allow the oilwater interfacial tension to be greatly decreased by order of 10-3mN/m to 10-4mN/m, hence avoiding the damages of alkali on oil-bearing strata and oil production equipments. References | Related Articles | Metrics

The Factors Affecting Abandonment Pressure and Recovery———Anexample of a gas reservoir in western Sichuan ZOU Jian-bo, LI Min, DAI Ping, MEN Qing-ping 2006, 27 (6):  736-739.  Abstract ( 85 )   PDF (155KB) ( 163 )   Save Numerical simulation as an effective method for determination of recovery of oil-gas reservoirs has been widely used to evaluatethe effects of different development schemes on the ultimate recovery of reservoirs with different types, different crude oil andpetrophysical properties. However, this method is scarcely used to estimate the recovery of a gas reservoir. Usually, formula method, gasreservoir driving type method and analogy method, etc., are used to determine the abandonment pressure or recovery. This paper, bymeans of numerical simulation study, evaluates the sensitivities of different factors affecting the abandonment pressure and recovery of agas reservoir in western Sichuan. References | Related Articles | Metrics

Status of Research on Vertical Conduit Flow of Gas-Liquid Two Phases in Wellbore WANG Hai-tao, YI Xiang-yi, LU Yuan 2006, 27 (6):  740-741.  Abstract ( 107 )   PDF (98KB) ( 339 )   Save The research on vertical conduit flow of gas-liquid two phases in wellbore aims at the classification, transition and judgement of flow pattern, according to the pressure distribution of oil-gas-water mixture in wellbore, by which the reliable basis will be provided for understanding of well performance, rational control/monitoring and regulating of well flow regime and the design of gas lift. This paper outlines the relevant results studied at home and abroad, based on which presents the evaluation and suggestions on the theoretical models given by scholars and the applied conditions of each model. References | Related Articles | Metrics

Automatic Tracing of Horizons Based on Higher Order Statistics PENG Wen, XIONG Xiao-jun, HAN Xiao-jun 2006, 27 (6):  743-744.  Abstract ( 83 )   PDF (150KB) ( 188 )   Save This paper presents a new method for tracing of horizons as required by detailed seismic interpretation, in order to eliminate the error in manual tracing of horizons. This method features strong noise elimination capacity, fast algorithm by four-order accumulative function and automatic adjustment of horizons in higher-order correlative calculation of manual-tracing horizons for getting more accurate horizons files. Case study shows that this method has strong theoretical and applicable values. References | Related Articles | Metrics

Application of Seismic Inversion Technique to Prediction of Volcanic Reservoir —An example of Block Zao-35 ZHENG Ya-bin, WANG Yan-bin, HAN De-xin 2006, 27 (6):  746-748.  Abstract ( 95 )   PDF (182KB) ( 234 )   Save This paper presents two methods of seismic data inversion for study of volcanic reservoir of Block Zao-35 in Huanghua depression: the well log constrained wave impedance inversion and the neural network-based multi-attribute inversion. The former is one of model-based seismic inversion, helpful to recognize the structure of volcano, laterally predict the volcanic rock and classify the volcanic process stage; the latter provides the ranges of thickness and physical property of volcanic rocks by the inversion, combined with lithology, well logs and seismic parameters. The results of inversion could be as bases for geologic modeling and reserves calculation of volcanic reservoir. References | Related Articles | Metrics

Application of Spectral Imaging Technology to Early Stage of Oilfield Exploration HU Yu-fang, ZHANG Yun-mian, YANG Jian-xun, ZHONG De-ying, ZHA Chao-yang 2006, 27 (6):  749-750.  Abstract ( 69 )   PDF (162KB) ( 209 )   Save Spectral imaging can be used to convert seismic data from time domain to frequency domain, and the resolution of thin reservoirs can be greatly improved using its separate frequency processing technique. This paper presents the principle and the maximum resolution of the spectral imaging followed by taking a case study as an example to discuss the application of this technique to sedimentary facies classification and the practical significance of it in progradation and retrogradation identification of sedimentary environment. The study shows that this technique can be used to well predict the changes of sedimentary environment of reservoirs and classify the sedimentary facies in the early of exploration by means of its feature of lateral high resolution. References | Related Articles | Metrics

Method for Natural Productivity Prediction in Production Testing Interval and Its Application to Tarim Basin KANG Yong-shang, HUAN Guo-qing, SONG Jian-xing 2006, 27 (6):  751-753.  Abstract ( 81 )   PDF (113KB) ( 255 )   Save It is precondition of preparing reasonable production testing scheme to precisely predict the natural productivity in production testing interval. This method for the natural productivity prediction is proposed based on analysis of plenty of logging and production testing data, by which several solutions to gain permeability could be provided; using logging data to predict both stock tank oil viscosity and in-situ crude viscosity is presented, and a regression equation for fluid productivity index vs. flow coefficient is established by Darcy equation. This method is characterized by fewer and easily acquired parameters, precisely predicted results and better practicability and feasibility. It is used to provide direct and reliable bases for the interval preference and the scheme optimization of production test. References | Related Articles | Metrics

Application of Homotopy BP Algorithm to Prediction of Reservoir Parammeters CHENG Hong-liang, FAN Xiao-min, ZHANG Li-hua 2006, 27 (6):  754-756.  Abstract ( 77 )   PDF (119KB) ( 180 )   Save Homotopy algorithm is a new method for solving nonlinear optimization problems. This paper introduces the homotopy algorithm into back-propagation neural network and indicates that the convergence speed can be improved and the defects of converging to local extremum can be eliminated. It is of rapid convergence speed, high convergence precision and good stability. Application of the algorithm to predicting reservoir parameters could improve the reliability of the parameter prediction. Case study proves its effectivity in prediction of reservoir parameters. References | Related Articles | Metrics

Non-Biostratigraphical Methods for Dating ZHAO Jun-feng, LIU Chi-yang 2006, 27 (6):  757-762.  Abstract ( 79 )   PDF (180KB) ( 180 )   Save Dating of the absolute ages of strata is one of the fundamental topics in the field of geology. All kinds of non-biostratigraphical methods for dating (not including the methods for young sediments and magmatic rock herein) reported at the present time are summarized as 6 categories. Their basic theories, operating processes, working conditions and successful cases and so on are commented one by one. The common advantages of dating methods based on magnetostratigraphy, Milankovitch cycles and Strontium isotope are global correlativeness and isochronism, but they all belong to indirect dating methods. The merit of methods based on cosmic dust elements is to determine the interrupted interval of sedimentation. The common advantage of methods based on fission track or radioactive isotopes is to directly estimate the absolute ages of strata, but rigorous limits on sample type and conservation degree are required at the same time. The principle that we should follow with regard to strata dating is integrated verifying, multi-discipline intercrossing, all-directionally developing and extracting the information contained in strata. References | Related Articles | Metrics

The Definition and Characteristics of Coalbed Methane and Coalbed Methane System ZHU Zhi-min, YANG Chun, SHEN Bing, CUI Hong-qing 2006, 27 (6):  763-765.  Abstract ( 171 )   PDF (96KB) ( 465 )   Save The precise definition, systematic method and thought of coalbed methane redound to in-depth coalbed methane study. The origin of coalbed methane is multi-original and it has multi-occurrence in coalbed based on summing up the latest information and literatures, combined with the experience and practice of coalbed methane exploration. The coalbe methane is natural gas in coalbed and the coalbed methane system is a natural system that encompasses coal beds and coalbed methane in them as well as all the geologic elements and processes as required for forming a coalbed gas pool. The coalbed is the focus of the coalbed methane system. References | Related Articles | Metrics

An Analysis of Difference of In-Place Oil and Gas Property LI Chuan-liang, ZHANG Xue-lei 2006, 27 (6):  766-767.  Abstract ( 167 )   PDF (59KB) ( 149 )   Save There are lots of differences for in-place oil and gas property. The main reasons for these differences are analyzed in terms of mechanisms of hydrocarbon generation, migration and accumulation. The first reason for that is the type of depositional organic matter and process of hydrocarbon generation; the second one is the differential gathering and gravitational differentiation. The post-diffusion and-oxidation is the major cause of densification of in-place oil. References | Related Articles | Metrics

A Discussion about the Universal Equation for Calculation of Heavy Oil Viscosity in Liaohe Oilfield LU Gang, LI Xin-qiang, YANG Zhao-chen, XING Yu-de 2006, 27 (6):  768-769.  Abstract ( 83 )   PDF (63KB) ( 205 )   Save The regression analysis of seven groups of viscosity-temperature data from Liaohe oilfield published in Ref. [1] of this paper is made, and the results are compared with those from Ref. [1]. It is found that the regression coefficient calculation from Ref. [1] is in error. The error analysis indicates great effect of the regression coefficient on the precise of viscosity calculation. In addition, the denomination of universal equation given in Ref. [1] is oppugned, and it is better regarded as the empirical equation. References | Related Articles | Metrics