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01 April 2005, Volume 26 Issue 2 Previous Issue    Next Issue

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Research and Dicusisn on Organie Matter HroronoCeneraig Mechanism through Multichain Reaction---A microphysical interpretation of organic matler hydrocarbon generation ZHOU Yan-ru 2005, 26 (2):  119-125.  Abstract ( 103 )   PDF (907KB) ( 335 )   Save The principle of activated energy theory is applied to examine the effect of active molecule in process of organic matter hydrocarbon generation. First of all, the properties and evolvements of lattice water of clay minerals in source rocks and interlayer water of clay mineral aggregates are clarified. Secondly, the principle and mechanism of forming proton acid bundle (H+) from active molecule (H20) are presented, including hydrodewater and hydrodecarboxylic acid reactions during soluble organic matter hydrocarbon generation; and the proton acid bundle of active molecule (H20), the cracking hydrocarbon generation by multichain reaction bombarded by macromolecular kerogen and property and composition of its hydrocarbon products are discussed. Finally, the reason for stereo-isomer variation of cholestane in different depths and abundances are explained. References | Related Articles | Metrics

Non-Structural Reservoir Prospecting of Terrestrial-Ramp Lake Basin in Junggar Basin LI Li-cheng 2005, 26 (2):  126-128.  Abstract ( 90 )   PDF (346KB) ( 251 )   Save Junggar basin has now been entered into the strategic turning stage for non-structural oil-gas rese凹oir prospecting. Given depositional features of Jurassic and Cretaceous, this paper presents the dominant factors that shape the nonstructural reservoir and favorable areas searching for such reservoirs. The study indicates that deposits of fluvial facies and delta facies are dominant belts for forming the non-structural traps in hinterland of Junggar basin; the unconformity between Jurassic and Cretaceous acts as the major channel for petroleum migration; the northeastward salient of Late Jurassic has significant effect on controlling the formation of non-structural reservoirs,and the northwestern margin slope, the Luliang south slope, especially the north slope of Changji sag in Junggar basin are favorable areas for forming the non-structural reservoirs. The explorative practice shows the best way searching for the non-structural reservoirs in Junggar basin should be full application of 3-D seismic fruits and detailed research of depositional strata as target zones under the proper calibration of regional prospecting wells. References | Related Articles | Metrics

Relationship between Himalayan Movement and Hydrocarbon Accumulation in Southern Margin of Junggar Basin KUANG Jun, JIA Xi-yu 2005, 26 (2):  129-133.  Abstract ( 102 )   PDF (776KB) ( 366 )   Save Himalayan movement originated from powerful compressive stress in Tethys tectonic domain, which caused north Tianshan mountains to quick and extensive uplift and thrusting toward Junggar basin followed by shaping foreland depression of intracontinental orogenic type developed in the southern margin of Junggar basin. It is Himalayan movement that controls the late hydrocarbon accumula- tions in Junggar basin. It is concluded that quick deposition of huge thickness of molasse formation brings the sonrce rocks of Mesozoic and Cenozoic into maturity stage and hydrocarbon expulsion in the foreland depression of this southern margin where forms the anticlinal structures in row and belt in the episode of Himalayan movement and some gentle or low-amplitude arch structures in northern Junggar basin. They provide favorable sites for such late hydrocarbon accumulations. Also, the faults as channels for petroleum migration in the whole basin have been intensified by the Himalayan movement. References | Related Articles | Metrics

On Genesis of Complex Normal Faults in Compressional Basin---An example of Gongshanmiao structural faulting in middle Sichuan basin QIN Qi-rong, LI Le, SU Pei-dong, XU Duo-wu 2005, 26 (2):  134-136.  Abstract ( 87 )   PDF (513KB) ( 303 )   Save The genetic analysis of faulting system in Gongshanmiao structure of middle Sidman basin show that nonnal faults in compressional basin are complex normal faults with normal fault effect. due to conversion of structural compressional stress followed by causing sheared and opened faulting，This gentic result has been verified by numerical analysis and Griffith's theory in terms of geologic analysis. It is of importance to interpretations of seismic data from compressional basins. References | Related Articles | Metrics

Depositional System of Sangonghe Formation of Lower Jurassic in Hinterland of Junggar Basin WANG Ju-feng, DENG Hong-wen, CAI Xi-yuan 2005, 26 (2):  137-141.  Abstract ( 73 )   PDF (933KB) ( 227 )   Save This paper reviews the microfacies' type and markers of Jurassic Sangonghe formation in hinterland of Junggar Basin based on core observation and combining with the variation of sand percentage as well as drilling/logging features and seismic reflection indicators, and points out that the growth and distribution of the sand microfacies in Sangonghe stage are controlled by the depositional sources form both northeast and northwest directions. The changes of datum level and A/S ratio and the diversity of depositional source systems and paleo-relief cause the differences in sedimentary facies type and volution characteristics of eastern and western parts of the study area. Ver- tically, the sedimentary facies has undergone the changes from braided river delta (fan delta) to meandering river delta to lacustrine facies, among which the mouth bar sands at the delta front formed in middle and late Sangonghe stage and those of underwater distributary chan- nel are the most important targets for exploration. References | Related Articles | Metrics

Hydrocarbon Accumulation of Shishugou Group in Cainan Oilfield LI Xing-xun, OU Ya-ping,SHENG Nan, ZHANG Wu, GU Xi-ping, QIN Xu-sheng 2005, 26 (2):  142-144.  Abstract ( 103 )   PDF (682KB) ( 233 )   Save In October, 2002, high-yielding oil-gas flow gushed in C125 Well at Jurassic ishugou group started historical breakthrough in rolling exploration and development of this group in Jundong (eatem Junggar basin） area. Shishugou group is a typical low sistance reservoir with section span of 360 m, thin interbedded sands and great lateral variation, which brings the difficulty for rolling exploration and development. Therefore, further recognition and research of its petroleum accumulation mechanism are of great importance in the next step prospecting. In enns of structure, sedimentary setting and petroleum accumulation, this paper analyzes he reservoir-controlled fac- tors as guide for the next step work. References | Related Articles | Metrics

On Genetic Type and Reservoir Quality of Jurassic Sands in Hinterland of Junggar Basin KUANG Jun, SI Chun-song, TANG Yong, WANG Xin 2005, 26 (2):  145-147.  Abstract ( 102 )   PDF (438KB) ( 265 )   Save There exist many types of genetic sandbodies of Jurassic in hinterland of Junggar basin, in which submerged distributary chan- nel sandbody in delta front subfacies is the major reservoir. The different kinds of genetic sandbody show the different superimposed structures. The sandbody of J,s,2 is of split planar texture, while the rest sequence sandbodies are dominated by labyrinth-like ones. The size grade of each genetic sandbody mainly controls the sandstone physical properties. The coarse-grained sandbody shows better property, depending on the depth. The petrophysical property of channel mouth bar in moderate-shallow depth are good as that of submerged dis- tributary channel sandbody; however, that of submerged distributary channel sandbody in deep-intennediate depth is better than that of the mouth bar sandbody; and that of super-deep sandbody shows little variation. References | Related Articles | Metrics

Organic Geochemistry of TD-2 Well in Tarim Basin MA An-lai, ZHANG Shui-chang, ZHANG Da-jiang, LIANG Di-gang, WANG Fei-yu4 2005, 26 (2):  148-151.  Abstract ( 102 )   PDF (639KB) ( 438 )   Save A little heavy oil was acquired from Well TD 2 in Cambrian reservoir in the eastern central uplift of Tarim basin. The oil 1s characterized by high Pr/Ph, high gammacerane, high 24 norcholestane, high C28 sterane, high dinosterane and triaromatic dinosterane, high 4 methyl 24-ethyl cholestane and 4-methyl-24-ethyl triaromatic cholestane. The geologic analysis and oil-source correlation showed the heavy oil originated from the Cambrian source rock. The 25-norhopane series of the oil indicated that the oil had been hiodegraded. A large amount of the phenanthrene, flnoranthene, henzoanthracene, henzofluoranthene, pyrene and the homogenization temperature of the fluid inclusion suggested the oil has suffered thermal lteration. Combined with the burial history of Well TD-2, the homogenized temper- ature of the fluid inclusion indicated the oil formed dming (450~44)×106a． References | Related Articles | Metrics

Relationship between Formation Water Salinity and Hydrocarbon Accumulation in Huanghenan Area LEI Li-an, XIE Li-hua, WANG Jin-zhi, ZENG Ping 2005, 26 (2):  152-154.  Abstract ( 98 )   PDF (782KB) ( 239 )   Save Based on formation water analysis data from Huanghenan area in Dongpu sag, the salinity variation and origin of the formation water are discussed, and the relation of the formation water salinity to sedimentary environment and oil-gas distribution is expounded. It is pointed out that the area or zone with high salinity possesses high abundance of organic matter and enough supply of oil source. So it is favorable area for oil-gas accumulation. TI1e authors proposed viewpoint that pools with both source and reservoir could be found in the zone with high formation water salinity. The rolling exploration/development practice in recent two years has gained outstanding effectiveness with incremental the cumulative proved reserves of over 1000x104t. References | Related Articles | Metrics

Stable Carbon Isotope and Its Significance in Hydrocarbon Accumulation in Tahe Oilfield, Tarim Basin WANG Chuan-gang, WANG Tie-guan, HE Fa-qi, WANG Jun-qi 2005, 26 (2):  155-157.  Abstract ( 103 )   PDF (824KB) ( 330 )   Save Oils from different blocks and horizons in Tahe oilfield belong to the same oil group. The difference of stable carbon isotope is not resulted from the parent source.The oils have less distinct differentiation with alkane δ13C ranging from -31.8‰ to-33.2‰, while the 813C valne distinction of whole oil, aromat町， nonhydrocarbon and asphaltene fractions of diverse reservoirs become bigger and bigger, es-pecially the Ordovician oils of 4, 6 and 7 districts, which has a lower asphaltene 813C value than the aroma, nonhydrocarbon, and further-more the whole oil of itself. This upside-down phenomenon is due to biodegradation by detailed geochemical analysis. Study shows that there exist two stages of recharging events, with low maturity of oils at early reservoir accumulation and lower carbon isotope value; follow-ing the biodegradation, nonhydrocarbon- and especially asphaltene-dominated group fraction are remained and mixed with late stage of recharging oil, indicating a complex feature of the stable carbon isotope distribution. References | Related Articles | Metrics

Relationship between the Sequence Stratigraphy Framework and Petroleum Accumulation in Lower Member of Xingouzui Formation, Eastern Jianghan Basin HU Tao, CHEN Su 2005, 26 (2):  158-161.  Abstract ( 86 )   PDF (879KB) ( 253 )   Save The lower member of Xingouzui formation is the major exploration target stratum in eastem Jianghan basin, and mainly consists of one 3-order sequence (SⅢ1). The pool -forming geological elements, reserves and reservoir types distribute in the sequence stratigraphic framework. Source rocks are found mostly in transgressive system tract (TST) of SⅢ1, whilst sandstone reservoirs occurs in lowstand sys-tem tract (LST) of it. There are regional sealing and partial sealing in SⅢ1, which vertically formed three types of source -reservoir cap rock combinations. The proved reserves pri marily distribute in the IST, secondly in the TST. Each system tract of SⅢ1 has different pool-forming types for diferences in reservoir conditions References | Related Articles | Metrics

The Formation Pressure Distribution in Boxing Area WU Wei, JIANG You-lu, LU Xue-song 2005, 26 (2):  162-163.  Abstract ( 113 )   PDF (449KB) ( 294 )   Save The method of predicting formation pressure using sonie logging data is presented. The self potential and micro electric logs are used to calibrate the shale interval in F1I Well of Dongying sag. From the pressure profile dist ribution plot and top interface pressure dis-(tribation plot of Es3, Boxing region is of high pressure in north and low pressure in south. Two high pressure areas are located in Chunhua uplift and Dahulu subsag compared with two low pressure areas in Qingcheng swell and south slope. It is believed that cerlain correlations seem to have between the pressure distributions and hydrocarbon migration and distribution. That is, oil and gas always migrate from high pressure area toward low pressure area. So pressure is one of the most important powers for petroleum mi gration in this region. References | Related Articles | Metrics

Geologic Model for Fault Sealing Evaluation of Superimposed Basins LI Ping-ping 2005, 26 (2):  164-166.  Abstract ( 94 )   PDF (315KB) ( 231 )   Save A superimposed basin tends to containing complex petroleum system, which leads to pa1ticular evaluation of its fault sealing. Based on previously studied results, the mechanism of fault sealing and such controlling factors as occurrence, mechanical nature and stress condition of fault, as well as filled material nature, geologic setting and activity in fault are reviewed, and a geologic model for evaluation of it is developed. Also, how to set up a mathematical model to carry out qualitative-quantitative evaluation using this model is discussed. With the complex petmleum system concept, fault sealing history and key time matching for generation and expulsion of hydro-carbons, this model could be served to in-deplh evaluation of fault sealing in supe1imposed basins in China. References | Related Articles | Metrics

Sedimentary Fades of Limestone of Sand Layer-1 in Zhenglizhuang Area, Dongying Sag CHEN Gang-qiang, WANG Wei-feng, JI Ling 2005, 26 (2):  167-169.  Abstract ( 106 )   PDF (765KB) ( 250 )   Save A set of carbonate lamination and sand-shale interbedding, with thickness from 30 to 60 meters, is found in the top of sand layer-1(Es1),Zhenglizhuang area, Dongying sag. The carbonate rock is mostly composed of biogenic limestone, which can be divided into shore-lake subfacies, shallow-lake subfacies and semideep subfacies, based on water depth and hydrodynamic condition, where shallow-lake subfacies could be further divided into biogenic shoal microfacies and bank-inset microfacies. Such a biogenic shoal microfacies is characterized by extensive distJ??bution, smooth top and thin sedimentary thickness. The biogenic limestone originated from shallow lacus-trine sediment has preferable porosity and permeability as well as connectivity, being as a good reservoir.The sediment shapes in stage of minute depressing and extension of the lake basin, for which the tectonic movement is relatively calm, but existed intermittent basement subsidence leads to episodic changes in water depth, resulting in deposits of carbonate and sand-shale interbedding. References | Related Articles | Metrics

Genesis and Significance of High Lime Sandstone in Toutunhe Formation, Shinan-21 Wellblock, Junggar Basin LIU De-guang, LING Yun, YANG Zhao, WANG Gui-jun 2005, 26 (2):  170-171.  Abstract ( 156 )   PDF (276KB) ( 299 )   Save Based on the macro- and micro-distribution characteristics of high lime sandstone of Jurassic Toutunhe formation in Shinan-21 Wellblock, Shinan oilfield, Junggar basin, this paper presents the origin and significance of the high lime sandstone, and points out that its distinct isochronous and isopath properties may be regarded as an important horizon marker for subdivision and correlation of J2t2 sand layer of Toutunhe formation.The subdivision concept proposed herein could be as a guide for detailed reservoir characterization and further development scheme preparation of this oilfield. References | Related Articles | Metrics

Sedimentary Fades of Upper and Lower Youshashan Formation in Altun Slope Area, Qaidam Basin DAI Lln, JI You-liang, LIU Cheng-xin 2005, 26 (2):  172-174.  Abstract ( 122 )   PDF (883KB) ( 592 )   Save This paper presents the in-depth sedimentary facies characteristics of upper and lower Youshashan formation in Altun slope area, Qaidam basin based on the sequence stratigraphic study, and includes the alluvial fan facies, the fluvial-floodplain facies, the delta facies, the fan-delta facies and the lacustrine facies, etc. Using four second-order sequences identified, plane distribution of each sedimentary facies is discussed, and the Neogene lake basin evolution and eastward movement caused by tectonic uplift are speculated. In terms of pale ostructure, paleoclimate and sedimentary source recharge, the dominant factors for Youshashau sedimentary facies evolution are analyzed. References | Related Articles | Metrics

A Study on Stratigraphic Erosion Thickness in Xihu Sag, the East China Sea Basin WANG Zhen, ZHANG Ming-li, WU Fa-dong, WANG Zi-yu, WANG Lin-sheng 2005, 26 (2):  175-177.  Abstract ( 106 )   PDF (695KB) ( 501 )   Save Since Late Cretaceous, Xihn sag in the East China Sea basin underwent chasmic stage, depression stage and regional subsid-ing stage, shaping several extensive regional unconformities (seismic reflection interfaces) such as T02(hottom of Pliocene), T42 (bottom Miocene), T03(bottom of Oligocene), causing intensively stratigraphic erosion. This paper presents the basic principle and approach for cal-culating the stratigraphic erosion thickness by means of geologic analogy method, analyzes the affect of the erosion on oil-gas accumnla-tion by taking 26 major seismic line profiles in xihu sag as examples, and probes into the applicability of this approach. References | Related Articles | Metrics

Choice and Adjustment of Pattern Well Networks WANG Jun-kui, CHEN Guo-xun 2005, 26 (2):  178-180.  Abstract ( 101 )   PDF (548KB) ( 235 )   Save The ratio of producers'productivity to injectors' injectivity for areal well pattern can greatly affect the choice of reasonable injection mode. With the increase of productivity injectivity ratio, the ratio of injection-production wells should be added properly. With prnductivity much lower than injectivity, inverted nine-spot injection pattern is the optimum selection; with productivity-injectivity ratio approaching 0.25, four-spot pattern will be proper; with productivity close to injectivity, five spot injection pattern will reach higher production rate. The simple formula for calculation of reasonable ratio of injection-production wells is presented. It is suggested that with mobility ratio of low permeability reservoir of less than 1, adopting inversed nine-spot injection pattern is improper, and several main adjust-ment modes for inverted nine spot injection pattern are introduced in this paper. References | Related Articles | Metrics

Estimation of Gas Well Dynamic Reserves by Integration of Material Balance Equation with Binomial Productivity Equation CHENG Shi-qing, LI Ju-hua, LI Xiang-fang, YANG Fa-dui, WANG Yu-quan 2005, 26 (2):  181-182.  Abstract ( 107 )   PDF (268KB) ( 366 )   Save The calculated gas well flowing pressure by integrating material balance equation for gas poor with binonial productivity equa-tion is matched to real flowing pressure curves from production history by modified Gauss-Newton method. Dynamic proved reserves of a gas well in pre-production phase are also estimated. The study shows that the integrated method proposed considering bottomhole pressure change more properly reflcts the dynamic reserves in pre-production phase. References | Related Articles | Metrics

Uncertainty of Aquifer Size Based on Material Balance Equation for Gas Reservoir LIU Yi-jiang, KANG Xiao-dong, LI Xiang-fang, CHENG Shi-qing, QIN Kai-feng 2005, 26 (2):  183-185.  Abstract ( 77 )   PDF (467KB) ( 172 )   Save Material balance equation for gas reservoir is an important method in gas reservoir engineering. In gas reservoir there exist elastic energy of rock, imeducible water, gas and aquifer, which are determined by critical parameters that consist of static parameters such as reservoir and fluid quality, gas reserves, aquifer size and dynamic parameters such as average pressure and accumulative production, etc., but these parameters are of uncertainty at the early stage of gas reservoir development. This paper presents the new equation for aquifer evaluation of elastic waterflood gas reservoir derived from material balance equation and the analysis of uncertainty of aquifer size in early stage of gas reservoir de velopment. References | Related Articles | Metrics

CawWaterFlow Dgital siuator orLow Pemebilly Gas Reservoir with Slippage Effet YAN Wen-de, GUO Xiao, JIA Ying 2005, 26 (2):  186-188.  Abstract ( 80 )   PDF (428KB) ( 305 )   Save Low permeability gas reservoir is normally charaoterized by low porosity, low permeability and high water saturation, and the existence of slippage efect is obviously found in gas flowing through porous media without ireducible water. The tighter the roek, the lower the permeability, and the more obvious the slippage efeet is. However, common gas reservoir model is never the less used for numerical simulation study of low-permeability gas reservoir, which leads to more differences between development indices predicted and real ones. The mechanism of percolation in low-permeability gas reservoir is analyzed. The nonlinear percolation mathematic model to both gas and water is then developed. Furthermore, the related numerical and simulation mnodels and simulator are established, considering the concept of gas relative permeability with the slippage effect. References | Related Articles | Metrics

Mechanism of Enhancing Heavy Oil Well Productivity by Sand-. Producing Cold Production HE Guan-jun, DU Zhi-min, XIONG Zhong-hui 2005, 26 (2):  189-190.  Abstract ( 93 )   PDF (250KB) ( 272 )   Save This paper presents the in-depth research of mechanism of enbancing heavy oil well productivity by sand-producing cold pro-duction and includes the increase of fluid flow by sand inflow; the formation of high permeability area; the formation of foaming oil and the decrease of skin effect. They may improve the understanding and recognition of the theoretical basis of sand-producing cold produc-tion in heavy oil well. In addition, the study indicates that the mechanism enhancing well productivity and factors controlling sand pro-duction are changing with time. References | Related Articles | Metrics

Effect of Stress Sensitivity on Productivity of Low-Permeability Sandstone Gas Pool ZHENG Wei-shi, LIU Yi-fei, HE Qiu-xuan 2005, 26 (2):  191-193.  Abstract ( 82 )   PDF (502KB) ( 320 )   Save One of main damage fetos in low peme bili sndsase gas pol is stes sivi. degre of which is dependen on rock's fature. The compotion, conlen, dstibuion of gains, cement, pore stucture and throat feture are all iner factors that afet and demine the size of stress sitviy. Duing the rseach of stes sesitvity damage of low pemebiltly sandsone gas pol, natural cores aroe used for the eperimental anlysi, and empirial equation beween abolute pemebliliy and alete pesure is given. Baed on this equation, the poduetvity and pessure dstibuion equatios of low pemabiltly sandstone gas pool are derived wih cnsidera tion of sres sitviy. Furthermore, the efcts of stres sesitvity on the podutivity of sandstore ges pol are dscussed. References | Related Articles | Metrics

An Easy Way to Ascertain Binomial Equation of Well Productivity LUO Yin-fu, WANG Nu-tao, HUANG Bin-guang 2005, 26 (2):  194-195.  Abstract ( 79 )   PDF (175KB) ( 224 )   Save Since turbulence effect appears near wellbore in oil well with high-speed flow, Darcy's Law for flat radial flow is incompletely applicable. Reference [1] presented the incomplete binomial equation of oil well similar to gas well under the condition of high speed tur bulence effect. Based on that, this paper proposes an easy way to determine binomial equation of well productivity without regard to for-mation static pressure, established by flowing bottomhole pressure and production data as well as linear regression. Using this equation, absolute open-flow capacity can be obtained. Case study shows this method is accurate and reliable for use. References | Related Articles | Metrics

OiI-Water Simultaneous Production Technology and A pplication Effect in H ongnan Edge- Bottom Water Reservoir, Tuha Basin LI Yan-ming, WEI Shang-wu, LI Xu-dong, TAO Lin-ben 2005, 26 (2):  196-198.  Abstract ( 72 )   PDF (316KB) ( 207 )   Save Oil-water simulaneous production, a new technology developed abroad since 1990s, is primanily applied to eliminale or control water coning in reservoir with botom water. With numerical simulation method, it is preferred ihat the proper time of oil- water simultane-ous production is when water cut reaches 30%~40%, the reasonable perforation position in water layer is near oil-water contact, the best water- oil ratio is 3:1. Three-well response evaluation shows that oil-water simultaneous production can effectively control raise of water cut, make oil production stable and enhance oil recovery. References | Related Articles | Metrics

Approach to Low-Amplitude Trap Identification in Junggar Basin一-An example of trap al Peng-5 Wellblock LI Xue-yi, LI Tian-ming, WANG Bing, XUE Lie ,XU Qun-zhou 2005, 26 (2):  199-201.  Abstract ( 68 )   PDF (629KB) ( 245 )   Save The stratigraphic trap idenification is becoming more and more difcult with progressing petroleum exploration in Junggar basin. How to find the low-amplitude traps in it? Taking P-5 Wellblock in Junggar basin as an example, this paper examines the inconsis-tence between drilling and seismic interpretation for its low-amplitude trap identification, and includes the detailed analysis of subsurface velocity feature and seismic velocity data and the development of the velocity model. With the model showing forward modeling and veloc-ity field modeling, remapping of the structure in P-5 Wellblock is made. The result shows that the existing trapping area becomes larger than before, and high spot moves four km toward southwest, which has been confirmed by drilling. References | Related Articles | Metrics

Correction of Results from Hydrocarbon-Generating Simulation GAO Gang, LIU Guang-di, WANG Zhao-feng 2005, 26 (2):  202-205.  Abstract ( 67 )   PDF (639KB) ( 222 )   Save Base on thermal simulation experiment of lacustrine mudstone of Type 112 and petroleum generation pattern, this paper propos-es the correction method for estimation of hydrocarbon generating quantity in oil gas bearing basin from the thermal simulation result. It is suggested that these thermal simulation result can not directly be used to estimate the quantity due to presence of certain errors compared with real hydrocarbon-generating patterms. The sclection of vitrinite reflectance at oil generating peak when correction should be based on measured source rock evolutive section in a basin for different basins or different source rocks have somewhat different vitrinite re-flectance. In addition, no distinct relationship between hydrogen and methane in hydrocarbon-generating mechanism means that estimation of gas quantity should exclude hydrogen in gross gaseous hydrocarbons. Corrected vitrinite rellectance has to be adopted to develop mathematic models for oil-gas production rate and related charts. References | Related Articles | Metrics

Assessment of Overall Benefit Status in Oil Region CHEN Guo-li, WANG Hong-tao, TIAN Wei, LUO Xian-kun, LIN Li-li 2005, 26 (2):  206-208.  Abstract ( 66 )   PDF (532KB) ( 166 )   Save On the basis of benefit evaluation of developed oilieldl block and single well in an oil region, it is necessary to make the as-sessment of the whole oil- gas producing benefis in an oil region. The indicators for asesmnent of the existing benefit status include the operation cost, oit production ratio of high-yielding block, oil production ration of high-cost block, marginal well or negative eficienl well ratio, break-even oil price -decision oil price ratio. Description and analysis of benefit status出well as prediction of benefil prospect in an oil region are made by using these 5 indicators. Results show that these methods can be well applied to comprehensively systenatically reflect the benefit status of an oil region. References | Related Articles | Metrics

Radial Basis Function Neural Network and Application to Data Interpolation YANG Yan-jun, YANG Yu, KANG Zhi-hong 2005, 26 (2):  209-211.  Abstract ( 90 )   PDF (307KB) ( 325 )   Save Neural network with radial basis function (RBF) is a new forward neural network proposed by Broomhead in 1988. It is of ad-vantage of fast computation and meeting regional optimizing demand, compared with common enor back- propagation network. In recent years it becomes of more interests and is introduced into computation of approxinating function interpolation. This paper presents the principle of neural network with RBF and the practicable interpolating computation. Case study shows it runs fast and reliably. References | Related Articles | Metrics

New Sereening Method for Reservoir by Natural Gas-Injection Miscible Flooding Process DENG Bo, XIONG Yu 2005, 26 (2):  212-214.  Abstract ( 92 )   PDF (382KB) ( 365 )   Save Natural gas injection miscible flooding is one of means for EOR. This paper presents the factors thal affect gas injection results based on the analysis of lean-gas and rich-gas injection miscible flooding mechanisms and gas injection performance analysis. by which the related assessment index systems are establisbed. Combining with reservoir physics and reservoir engineering evaluation methods, the rclated indices are quantified. The modern decision analysis method and optimal scheme index assignment inethod are used to syntbheti-cally screen and assess the candidate reservoir. The result shows that this method could reflect the influences of various factors on gas in-jection, and will be applied on pilot test. References | Related Articles | Metrics

Establishment of the Network Digitalized Core. Database System of Tuha Oilfield LIU Feng, ZHANG Hong-mei, QIN En-peng 2005, 26 (2):  215-216.  Abstract ( 97 )   PDF (240KB) ( 371 )   Save The demorphism, poor preservation and frequent sampling bring severe loss of cores. To solve this problem, the more efforts in core data digitization, high resolution core image acquisition, core datalbase with pictures and texts and its application on network have been made in different degrees in every oilfeld of China. As one of earlier oifield for doing so, it has set up a system of fairly perfect network digitized core database, and its establishment or application has improved not only the quality and level of core management,but also enriched the means for exploration and development researches,and raised the ability of scientific decision-making for those re-searches and production effectively. Related Articles | Metrics

Study on Petroleum Geology versus Fundamental Subjects LI De-sheng 2005, 26 (2):  217-220.  Abstract ( 130 )   PDF (955KB) ( 663 )   Save The development of petroleum geology depends upon the innovation of relevant theories and technologies. In te1ms of hydrocar-hon generation, geodynamics and reservoir characterization that are the most fundamental subjects contained in petroleum geology, this paper discusses the conditions for generating thought of innovation, and points out that connecting link between the preceding and the fol-lowing and getting rid of the stale and bring forth the fresh are the ruotivity of tbe innovation; being practical and realistic and being es-tablished in plentiful firsthand information are the bases of it; diligence and independent thinking are the key of it, and the innovations of theory and technology b1ing by all means into growing production capacity. These views are more constructive to all petroleum geologists. especially to young generation of them today. References | Related Articles | Metrics

Review on Petroleum Reserves Classification Revision in China ZHAO Wen-zhi, GAO Rui-qi, HU Su-yun, HU Yun-dong, BI Hai-bin 2005, 26 (2):  221-225.  Abstract ( 107 )   PDF (694KB) ( 392 )   Save The history of petroleum reserves classifications in China is reviewed. Two systems of petroleum reserves classifications applied in the world are proposed conclusively, they are, the assured reserves classification system and the probabilistic reserves classification system. Based on these, three critical differences in petroleum reserves classifications and management modes at home and abroad as well as the revision of domestic classifications are discussed. Some specific suggestions are put forward herein: 1) remain existing basic frame work for domestic reserves classification; 2) eliminate proved reserves classification;3) change technically recoverable reserves intoeco nomically recoverable reserves;4) introduce and generalize the probabilistic classification, and 5) subdivide the reserves classifications in terms of the China’s petroleum reserves classification system to meet the demand of the petroleum industrial development. References | Related Articles | Metrics

Characteristics of Source Rock of Shemshak Formation and Hydrocarbon Accumulation in Kashan Block, Iran LI Zheng, XU Xing-you, SONG Lai-liang, KONG Xiang-xing 2005, 26 (2):  226-229.  Abstract ( 95 )   PDF (916KB) ( 229 )   Save The Kashan block is a Precambrian metamorphic-based basin of Mesozoic and Cenozoic. Its source rock of Shemshak formation of Middle-Lower Jurassic on outcrop area is assured to be effective source rock by geochemical analysis of the abundance, type and maturity of organic matter, integrated with oil source correlation. The element evolvement for petroleum accumulation indicates that the region-al geological setting in this study area contributes to the formation and evolution of oil-gas reservoir. It is concluded that there exist both Tertiary reservoirs with source rock of Shemshak formation and primary reservoirs of it in Kashan block. References | Related Articles | Metrics