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01 August 2009, Volume 30 Issue 4 Previous Issue    Next Issue

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Create A New and Multielement Era for Energy Sources Development by Integration of Petroleum Geology with Environmental Geology LI De-sheng, LI Bo-hua 2009, 30 (4):  403-406.  Abstract ( 93 )   PDF (231KB) ( 328 )   Save This paper analyzes the world and domestic petroleum potential resources, proven in place reserves and recoverable reserves in 2007. The study shows that in the 21st century, oil and gas will still play important roles in the energy family. Chinese petroleum industry should make efforts on independent innovations in theory and practice for its extraordinary, energy-saved and globalized developments. The waterflooding process is still crucial technology for EOR in domestic oilfields. The CO 2 miscible injection in reservoirs for incremental EOR and reducing emission should be promoted and popularized in the future. The 21st century should be a multielement era for energy development, and in the 22nd century a global economic society with guarantee of renewable resources and/or new energy sources will be hopefully created. References | Related Articles | Metrics

Tectonic Systems in Northwestern China and Their Relations with Hydrocarbon KANG Yu-zhu 2009, 30 (4):  407-411.  Abstract ( 113 )   PDF (217KB) ( 253 )   Save The northwestern China refers to the area of the west of Helan mountain and the north of Kunlun mountain, with an area of about 200×104 km2 . More than 60 sedimentary basins are developed within this area, with and area of about 130×104 km2 . Up to now, more than 80 oil-gas fields have been discovered, of which 13 giant oil-gas fields indicate that this area is very rich in petroleum resources with 440×108 t oil equivalent, but extremely low in resource transformation ratio (about 8%), showing that it has tremendous potentials for petroleum exploration and could be one of major explorative areas for replacement of resources. In view of the structural system, evolution of petroliferous basins and control factors of oil-gas distribution, this paper discusses the oil-gas distribution rules and points out the directions or targets for petroleum exploration in this area in the future. References | Related Articles | Metrics

Subdivisions of the Central-East Asia Multi-Energy Minerals Metallogenetic Domain and Types of Those Basins LIU Chi-yang, QIU Xin-wei, WU Bo-lin, ZHAO Hong-ge 2009, 30 (4):  412-418.  Abstract ( 105 )   PDF (724KB) ( 304 )   Save According to the different characteristics of regional structures, basin's evolutions and mineralization conditions, the Central- East Asia energy minerals metallogenetic domain (CEAMD) can be divided into such four mineralization zones as Songliao-Ordos, Alashan-Hexi corridor, Xinjiang and Central Asia ones. The comprehensive analyses and comparisons of accumulation/mineralization conditions and current exploration of multi-energy minerals show that the relatively stable regional tectonic background and moderate (weaker) structural deformation are probably the necessary conditions for the formation, coexistence and preservation of large- and medium-sized sand-type uranium deposits, oil-gas fields and coalfields. The primary basins suitable for coexistence and accumulation of oil-gas, coal and uranium are the large- and medium-sized intracraton basins, intermediate massif basins and correspondingly split medium- and small-sized relic basins. The medium-sized rift basins developed in late of Mesozoic are also of the conditions of accumulation/mineralization and coexistence of multi-energy minerals. References | Related Articles | Metrics

Emei Taphrogenesis and Natural Gas Prospecting Practices in Sichuan Basin LUO Zhi-li 2009, 30 (4):  419-424.  Abstract ( 135 )   PDF (686KB) ( 304 )   Save It has been more than twenty years to study of Emei taphrogenesis since it was suggested. Emei taphrogenesis not only occurs in Sichuan-Yunnan-Guizhou areas in southwestern China, but also extends into the southern provinces (the South China plate) and surrounding areas. It was first suggested that the Upper Permian reef gas reservoirs should be put attention to in early 1980s, which played an instructive role in discovery of the Kaijiang-Liangping trough, could be as guides for finding out Puguang structural- lithologic gas field in 2002 and for exploration of Yuanba gas field in 2005. In addition, the researches on the Emei taphrogenesis and the Emei basalt benefits the study of the Permian and Triassic dolomite reservoirs and offers the necessary conditions for the formation mechanisms of the tectonic hydrothermal dolomite and basalt-leaching dolomite. It is predicted from the characteristic the taphrogenesis in the South China plate that the aulacogen may be another favorable area for gas accumulation in Mianzhu-Zhongjiang in western Sichuan, which should be paid great attention to. It is recommended that the research and prospecting of Guangwang-Kaijiang-Liangping aulacogen should be continuously strengthened, and hopeful of paying attention to the research of the taphrogenesis in progress of exploration of Tarim basin, and drawing on the experience of Puguang giant gas field exploration, in order to discover more and more petroleum resources. References | Related Articles | Metrics

Accumulation and Distribution of China's Marine Hydrocarbon Source Materials QIU Dong-zhou, ZHAO Yu-hua, LIU Chuan-peng, WANG Deng-wen 2009, 30 (4):  425-430.  Abstract ( 70 )   PDF (1016KB) ( 443 )   Save The accumulation characteristics and distribution rules of marine hydrocarbon source materials as foundations for hydrocarbon accumulation are extremely important and basic geologic conditions for exploration, which are elaborated in terms of hydrocarbon- generating material, hydrocarbon-storing material and hydrocarbon-sealing material for forming the marine hydrocarbons. The distribution of marine hydrocarbon-generating material is closely related to the changes of paleo-structure, paleo-sedimentary environment, paleo- climate and paleo-ocean. The developed horizons or levels always appear in transform stages of significant changes of tectonic framework and sedimentary basin in nature, with close relations to the global anoxic events. The distribution of marine hydrocarbon-storing material is mainly controlled by sedimentation, diagenesis and tectonic movement. The distribution of premium reservoir is commonly and closely related to low-level system tract and late high-level system tract in terms of second-class sea level change. The distribution of marine hydrocarbon-sealing material is coincident to that of marine regional source rocks, but the former is more plentiful than the latter in type. References | Related Articles | Metrics

Source Kitchen and Natural Gas Accumulation in Kuqa Depression, Tarim Basin WANG Fei-yu, DU Zhi-li, ZHANG Shui-chang, ZHANG Bao-min, CHEN Jian-ping, Bernhard Cramer 2009, 30 (4):  431-439.  Abstract ( 149 )   PDF (950KB) ( 503 )   Save Based on the simulated test data, the chemical kinetics parameters of natural gas generation rate and carbon isotope from the typical source rocks in Kuqa depression of Tarim basin are established. In view of the geologic data and the present- and paleo- geothermal data from exploration wells and artificial wells, the changes of maturity and gas generation rate with time for each well are analyzed with BasinMod software. And the hydrocarbon generating history and source kitchen evolution of Jurassic-Triassic source rocks are recognized. It is suggested that the late and fast burial and mature of source rocks in Kuqa depression since the Neogene, in particular, the rapid deposition of Kuqa formation since the Pliocene (5×106 a BP) lead to sudden increase of the maturity of source rocks, entering into dry gas stage with extremely high gas generation rate. This is a significant reason for formation of highly active natural gas pool in this depression. As shown by the chemical and stable carbon isotope compositions of the discovered gases, the formation of the giant gas pool in Kela-2, Yaha underwent very different geological processes due to the differences in their gas source kitchens. Gases in Yaha condensate gas field in the frontal uplift zone appear to represent gases generated within early to middle oil window with relatively isotopic light gas, whereas the isotopic heavy gases in Kela-2 gas field in Kelasu-Yigikelike Yi structural belt are most likely high maturity gases (Ro:1.0%~2.5%) generated since 5×106 a BP. References | Related Articles | Metrics

Different Orders of Unconformities and Their Oil-Gas Accumulations in Bohai Bay Basin JIN Qiang, YAN Zhao-min, CHENG Fu-qi, SU Chao-guang 2009, 30 (4):  440-444.  Abstract ( 124 )   PDF (707KB) ( 409 )   Save Based on the characteristics of tectonic movement and sequence stratigraphy in Bohai Bay basin, the stratigraphic trap development and oil-gas accumulation related with unconformities are presented. It is suggested that there are two first-order unconformities in the basin, i.e. Neogene/Paleogene and Paleogene/Mz-Pz unconformities. The former contains overlap trap reservoir in the sag's steep slope belt, and both overlap trap and unconformable barrier reservoirs in the ramp belt. The latter contains the buried hill reservoirs in swell and sub-swell. In the Paleogene, there are three second-order and ten third-order unconformities, and the stratigraphic reservoirs occur above and beneath the second-order unconformities, while the stratigraphic reservoirs related to the third-order unconformities appear in small scale and many numbers. Hence they are the main targets for recent fine exploration here. Through many- year exploratory practices in Jiyang depression, numerous such stratigraphic reservoirs have been discovered, making great contributions to the energy strategy for keeping a stable production in eastern China. References | Related Articles | Metrics

The Control Factors of Shallow Hydrocarbon Accumulation and the Exploratory Directions in Che-Mo Paleohigh in Junggar Basin KUANG Jun, HOU Lian-hua, ZHANG Yue-qian, SHI Xin-pu, WANG Jing-hong 2009, 30 (4):  445-449.  Abstract ( 77 )   PDF (400KB) ( 243 )   Save The several methods are used to recover the paleogeomorphology in Che-Mo paleohigh with the core, seismic and well logging data for revealing the control effect of sedimentary system and sand distribution on hydrocarbon accumulation within this paleohigh. It is suggested that the Middle Jurassic-Early Cretaceous is the period of Che-Mo paleohigh development, and its heyday appears in the late of Middle Jurassic. The inner-sources supplied from this paleohigh control the sedimentary system and sand distribution around it. The development and burial stage of the paleohigh play the roles in control of hydrocarbon accumulation. The oil-gas regulating, migration and secondary reservoirs distribution are controlled by the two-stage tilting regulations, inner-source sand distribution, fault system and present structure. The inner-source sands surrounding Che-Mo paleohigh and the matched area with present structure would be the favorable areas of lithologic-stratigraphic reservoir development, and the slope belt be the focus domain for the next exploration, based on which the breakthrough has been made by Well Mo-17. And the lithologic-stratigraphic reservoirs could be as the new domains around the paleohigh. References | Related Articles | Metrics

Characteristics and Exploration Direction of Cambrian-Ordovician Carbonate Rocks in Tarim Basin ZOU Cai-neng, LI Qi-ming, WU Guang-hui, MA Feng 2009, 30 (4):  450-453.  Abstract ( 122 )   PDF (329KB) ( 376 )   Save There are three depositional and structural cycles of the Cambrian-Ordovician carbonate rocks in Tarim basin, which form stable structural framework with uplifts and depressions reconstructed by four-stage tectonic movements and three types of reservoirs like reef flat, unconformity and dolomite. Followed by three-stage hydrocarbon chargings such as Caledonian, Late Hercynian and Himalayan orogenies, they become petroleum reservoirs. These carbonate rocks feature old ages and low matrix porosity, and secondary solution pores and vugs are the main reservoir pore spaces. The unconformable reservoirs and reef flat reservoirs are controlled by sedimentary facies and zones of steep hill and ramp. The unconventional carbonate reservoirs with large area, medium-low abundance and layer control are wide distributed. The low porosity and low permeability reservoir features and multistage hydrocarbon charging result in the differences of oil-gas-water distribution and production. The oil-gas distribution is controlled by the space-time configuration between paleo-uplifts and source rocks. The carbonate reservoir and late gas charging constitute the major controlling factors for hydrocarbon accumulation. It is concluded that the Paleozoic paleo-uplift slope areas are the main targets for petroleum exploration; Tazhong paleo-uplift, Lunnan and surrounding Ordovician systems are the realistic domains for exploration; Yi Maili-Yaha and Maigeti slope are strategically major explorative areas for replacement of resources; Gucheng, Tadong, deep Lunnan, deep Tazhong-Bachu dolomite of Cambrian are the favorable areas for exploratory researches. References | Related Articles | Metrics

Correlation of Jurassic in Northern Margin of Qaidam Basin and Its Petroleum System WANG Chang-gui, MA Li-xie, WANG Wen-di, QIAO Zi-zhen, HOU An-ping, GAO Xue-feng, REN Yu-fen 2009, 30 (4):  454-458.  Abstract ( 135 )   PDF (601KB) ( 468 )   Save The north margin of Qaidam basin is an old oil region. The Middle and Lower Jurassic strata are its main source rocks. Through regional studies, the Jurassic is divided into 3 series and four formations, i.e. Xiaomeigou formation of Lower Jurassic, Dameigou formation of Middle-Lower Jurassic and Hongshuigou formation and Caishiling formation of Upper Jurassic, of which Dameigou formation can be subdivided into 7 members. This paper presents the classifications and correlations of 38 wells encountered into the Jurassic one by one, and reviews the sedimentary characteristics of Lower Jurassic and Middle Jurassic, based on which the petroleum systems of the Lower Jurassic and the Middle Jurassic. It is concluded that the Lenghu-Nanbaxian arc structural belt and the Eboliang structural belt are favorable areas for petroleum exploration. References | Related Articles | Metrics

The Relationship Between Marine Carbonate Reservoir and Tectonics in Sichuan Basin YONG Zi-quan, LUO Zhi-li, LIU Shu-gen, SUN Wei, YANG Rong-jun 2009, 30 (4):  459-462.  Abstract ( 92 )   PDF (479KB) ( 390 )   Save Reservoir is one of key factors of hydrocarbon accumulation of marine carbonate reservoir in Sichuan superimposed sedimentary basin. The marine carbonate reservoir is controlled by the lifting and rifting movements, of which the karst reservoir is controlled by the unconformities formed by the uplifts in the lifting movement; the reef flat reservoir is controlled by the sedimentary facies differentiation resulted from platform block-trouph framework, including the reservoir distribution, dissolution, dolomitization, etc. in the rifting movement. References | Related Articles | Metrics

Geologic Structure and Volcanic Distribution of Carboniferous in Malang Sag in Santanghu Basin SUO Xiao-dong, LI Feng-xia 2009, 30 (4):  463-466.  Abstract ( 160 )   PDF (481KB) ( 261 )   Save The Carboniferous is a new petroliferous system in Santanghu basin, in which volcanic rocks are favorable oil-gas reservoirs. However, the long-term unclear recognition of internal structure of the Carboniferous and distribution of volcanic rocks in it influences the cause for petroleum exploration here, because it is hard to get effective seismic reflectance information from the deep sequences. The application of high-accuracy gravity-magnetic-depth sounding technology allows the previous seismic prospecting deficiency to be made up for, by the fact that the remained trough distribution and the sequence structures as well as the vertical and lateral distribution of volcanic rocks of the Carboniferous in Malang sag are basically recognized. The study shows that the remained trough of Carboniferous in southeastern Malang sag is a favorable target or direction for petroleum exploration. The Harjiawu formation of Upper Carboniferous belonging to low-resistivity bed with argillaceous clastic rock could be as a source rock, while the Kalagang formation and the Batamayineishan formation belonging to high-resistivity bed with volcanic rocks could be favorable reservoirs. The field-constructive sounding profile can be applied to vertically recognize the multi-set sequences and their volcanic bodies; the high-accuracy gravity and magnetic prospecting technology can be used for studying the lateral distribution of geologic bodies like volcanic rocks. It is suggested that the integration of these two technologies should be effective means for study of the geologic structure and volcanic rocks of the Carboniferous in this area. References | Related Articles | Metrics

Source Rock Characteristics and Resource Potential Evaluation of Hurenbuqi Sag in Erlian Basin CHEN Wu-quan 2009, 30 (4):  467-469.  Abstract ( 91 )   PDF (250KB) ( 224 )   Save The Bayanhua group of the Lower Cretaceous in the Hurenbuqi sag of Erlian basin develops a set of deposit of inland river- lake facies clastic rocks. Semi-deep and deep lacustrine source rocks commonly occur in the Tengge'er formation in eastern deep trough of the sag, dominated by lithology of dark gray and gray-black mudstone and shale, with the organic carbon content of greater than 5.0%, the chloroform bitumen "A" of greater than 0.5%, the total hydrocarbon of greater than 1 500 ppm, the type of organic matter is dominated by humosapropelic type (Ⅱ 1 ), and the vitrinite reflectance averaging 0.57%, indicating the thermal evolution is in low-mature oil-generating stage. The potential oil-generation rate is more than 60 mg/g. The total oil-generating quantity is 38.510 9×108 t. The total resource is 1.852 4×108 t in this sag calculated by means of chloroform bitumen "A" method, indicating it is of a certain of petroleum resource and explorative potentials. Among them, the 1st member of Tengge'er formation assumes the largest volume of resources of 1.573 9×108 t, being the main target for exploration. Regionally, some sub-sags in the south and north have the largest resources accounting for a total resource of 89%, being important areas for exploration. References | Related Articles | Metrics

Conditions of Hydrocarbon Accumulation in Shallow Reservoir in Shengbei Sub-Sag of Tuha Basin LIU Hu-chuang, JIN Ji-kun, SONG Hai-bo, NI Lian-bin, WU Chao, ZUO Xin-yu 2009, 30 (4):  470-473.  Abstract ( 74 )   PDF (329KB) ( 226 )   Save Shengbei hydrocarbon-prone sub-sag is oil-gas enriched unit with the most potential of resources in Taibei sag. Shengbei structural belt is located at the central uplift area in Shengbei sub-sag. The late maturation of hydrocarbon source rocks and the oil-gas migration and accumulation feature depend on the distribution and charging degree of the reservoirs. By little impact of the orogeny's compression in Shengbei structural belt, the upward migration and accumulation of hydrocarbon from source rocks are generally conducted along the faults. It is the low potential energy and low amplitude uplift that allow oil and gas to be accumulated into the reservoirs. In addition, such factors as the reservoir rock development and the facies-belt and petrophysical property changes, etc. play important roles for petroleum distribution in the target zones. The vertical phase state changes during migration of condensate gas result in gradual precipitation of condensate oil, and forming the distributing pattern of upper oil and lower gas, with the decline of temperature and pressure. Under the action of compressed centrifugal-flow formed by asymmetric hydrodynamic field, the oil-gas amount migrated through the lateral leading-zone towards basin edge could be far more than the amount migrated upward vertically through the fault connecting the deep strata in the center of the basin. Hence, at the same time of enforcing oil-gas exploration of the low-range uplift area in Shengbei sub-sag, the sub-sag slope and transition region should be regard as the major targets for exploration. References | Related Articles | Metrics

Lithologic Reservoir Exploration in Taibei Sag in Tuha Basin: Thought and Direction LI Zhi-jun 2009, 30 (4):  474-477.  Abstract ( 87 )   PDF (571KB) ( 446 )   Save This paper analyzes the special sedimentary environment and petroleum geologic conditions in Taibei sag in Tuha basin. For oil-gas accumulation pattern with source bed in lower formations and reservoir bed in upper formations, the good assemblage among source fault, paloestructual setting and lithologic trap is the key for hydrocarbon accumulation. In lithologic oil-gas reservoir exploration in Taibei sag, the lithologic trap is not only focused on, but also study of the source fault development feature, paleostructural setting of trap and related condition and process of oil-gas accumulation should be paid more attention to. Based on analysis of oil-gas accumulation characteristics, this paper proposes the thought, studied focal point and explorative direction in this area. References | Related Articles | Metrics

Classification of Carboniferous in Northern Xinjiang ZHAO Zhi-xin 2009, 30 (4):  478-482.  Abstract ( 174 )   PDF (288KB) ( 622 )   Save Based on the previous studies, the boundary between the Devonian and the Carboniferous and the middle boundary of Carboniferous are discussed. It is suggested that such formations as Yeliemodun, Baiyushan and Hala'alate are all the stratigraphic units for stradding the Upper and Lower Carboniferous. In this paper, the relationships among the Hongguleleng, Hebukehe, Gennaren and Heishantou formations are mainly discussed, and it is proposed that using the Heishantou formation substitutes for the Hebukehe and Gennaren formations. References | Related Articles | Metrics

Pressure Response to Hydrocarbon Charging Events in Es 3 Member of Minfeng Sub-Sag LIU Hui-min 2009, 30 (4):  483-485.  Abstract ( 83 )   PDF (401KB) ( 308 )   Save Minfeng sub-sag is a prospective area for lithologic reservoir exploration. 15 core samples from the Es 3 member of 8 wells are collected and prepared for fluorescence microscopy analysis of oil inclusions, petrographic characterization and microthermometry of oil and aqueous inclusions, and thermodynamic modeling of palaeopressure. The integrated results indicate that lithologic reservoir in this member underwent three periods of hydrocarbon charging events that happened during (28~25)×106 a, ( 7.1~3.4)×106 a and 1.1×106 a, dominated by late event since 7.1×106 a. The thermodynamic modeling results show that three cycles of pressure increase and decrease since the sedimentation of Ed formation are of coupling relationship with the three periods of hydrocarbon charging events. The first charging featured at normal pressure; the second one at abnormal pressure and the third one was divided into two states: the early dominated by abnormal pressure; the late dominated by normal pressure. References | Related Articles | Metrics

Derivation , Comparison and Application of Horizontal Well Production Formula Considering Anisotropy and Eccentricity Effects CHEN Yuan-qian, ZOU Cun-you 2009, 30 (4):  486-489.  Abstract ( 120 )   PDF (488KB) ( 228 )   Save In application of production rate formula for horizontal well, anisotropy and eccentricity should often be encountered, and dealing with this problem relates to the reliability of the calculated results. At present, such formulas considering these two factors were all proposed by Joshi. However, only the results from one factor or two factors were provided by Joshi without related concrete derivations, hence remaining the issues of reliability and validity of the formulas. In appendix of this paper, the production rate formulas for horizontal well considering anisotropy and eccentricity are re-deduced and new results and recognitions are obtained. The application of the formulas by Joshi and by Chen Yuan-qian indicates that: (1)the influence of anisotropy on horizontal well production rate is very obvious, and that of eccentricity on it is relatively small; (2)there exist big problems with the formula only considering eccentricity by Joshi; (3) in Joshi's formula considering these two factors, the influence of anisotropy should not be taken into account in the eccentricity term expressed by log form; moreover, the mark before the eccentricity should be plus sign but not minus sign. References | Related Articles | Metrics

A Study on the Maximum of Pressure Factor of Formation LI Chuan-liang 2009, 30 (4):  490-492.  Abstract ( 115 )   PDF (214KB) ( 299 )   Save Pressure factor of formation is defined as ratio of the measured formation pressure to the static hydraulic pressure calculated at the same depth. Formations with pressure factor over 1.2 are abnormally high pressure ones, which are certainly closed formations. The maximum pressure factor is about 4.0, which occurs only in compressive structures with lateral stresses being larger than overburden pressure. And also the formation rocks must be tight and well cemented. The surrounding rocks of formations must have strong closing ability. References | Related Articles | Metrics

A Study on CO2 Flooding Effectiveness and Its Geologic Storage YAO Yue-dong, LI Xiang-fang 2009, 30 (4):  493-495.  Abstract ( 112 )   PDF (250KB) ( 467 )   Save The numerous researches and applied results at home and abroad indicate that injecting CO2 into reservoir may greatly enhance oil recovery (EOR) and realize the long-term and in-situ geologic storage of CO2 . This paper presents the investigation of the status of CO2 storage and related EOR abroad and the latest trend, and studies the impact of reservoir quality, fluid property and recovery process on CO2 flooding and storage using numerical simulation method. And these influenced factors are comprehensively analyzed, according to the calculated results of reservoir parameters in pilot area, followed by that the evaluating indices for influencing CO2 storage and related EOR are determined, and these factors are evaluated. References | Related Articles | Metrics

Reservoir Modeling Technique Based on 3D Geological Objects— An example from SI reservoir in Wenjisang oil field ZHANG Chao-fu, LIU Bin, HE Bo-bin, QIAO Xiang-yang, LIU Ying, LIAO Hua-wei 2009, 30 (4):  496-498.  Abstract ( 86 )   PDF (381KB) ( 197 )   Save 3D geological object-controlled modeling is a reservoir modeling technique for controlling macro trends such as lithology and porosity structure. Compared with facies-controlled stochastic modeling technique, this technique is more applicable to reservoir evaluation, productivity construction and gas field lacking drilling data. It meets the need of fine reservoir description with the help of solving sharp facies changes and modeling stochastic characteristic. References | Related Articles | Metrics

Dynamic Reserves Calculation and Evaluation of Sebei Gas Field in Qaidam Basin GAO Qin-feng, DANG Yu-qi, LI Jiang-tao, YANG Sheng-bin, SHEN Sheng-fu 2009, 30 (4):  499-500.  Abstract ( 120 )   PDF (161KB) ( 280 )   Save Two typical gas reservoirs (X and Y) in Sebei No.1 gas field in Qaidam basin are evaluated for their dynamic reserves using material balance method and decline analysis method, in terms of SEC reserves evaluation methods, based on production performance data and test information. The existing calculated differences between the dynamic reserves and OGIP are rationally explained, integrated with production logging and perforation data. The results can be as a guide for highly effective development of next gas field in this area. References | Related Articles | Metrics

Analysis of Multi-Scale Seismic Information Differences in Reservoir Characteristics CAO Si-yuan, LIU Lan-feng, HAN De-hua 2009, 30 (4):  501-505.  Abstract ( 65 )   PDF (890KB) ( 166 )   Save The recognition of true and false bright spots is the key of success of lithologic oil-gas reservoir exploration. AVO (amplitude versus offset) theory provides theoretical basis for application of pre-stack information of seismic data to reservoir recognition. FVO (frequency versus offset) allows the prediction of reservoir using the post-stack information to be possible, despite its physical mechanism is now unclear. The numerical experiment indicates that the space variation of formation lithology can be reflected by the strike differences of different scales of seismic wave events in stack seismic record, and the strong amplitude caused by seismic wave tuning can be separated from that caused by reservoir's AVO applying the differences of multiple scales of seismic wave event reflectance energy. These provide a new method for effective recognition or distinguishing of reservoir for study of true and false bright spots in post-stack profile. Marmousi II model and real data processing show that this method can be used to recognize reservoir rocks. References | Related Articles | Metrics

Seismic Wave Field Simulation of Jurassic in Hinterland of Junggar Basin LIU Chuan-hu 2009, 30 (4):  506-508.  Abstract ( 112 )   PDF (344KB) ( 142 )   Save The Jurassic reservoir in hinterland of Junggar basin is characterized by deep burial depth, non-structural trap and big difficulty for petroleum exploration. This paper presents the physical model for the Jurassic reservoir in the basin. The simulated result matches to the field core statistical result in order to achieve high accuracy. Then the seismic wave field simulations are conducted. The study indicates that the weighted impedance attributes can be used to effectively distinguish fluid bearing sand from dry sand, through decomposition of P-wave information into rock rigid modulus and elastic modulus, thus highlighting the seismic attribute of fluid-bearing formations or sands. References | Related Articles | Metrics

The Method for Astronomical Period-Restricted Datum-Cycle Sequence Classification WANG Qi-cong 2009, 30 (4):  509-514.  Abstract ( 126 )   PDF (947KB) ( 239 )   Save Through the signal decomposition of gamma ray curves and the spectrum analysis of detailed components using discrete wavelet transform technique, the dominant frequency and sedimentary cycle thickness for the detailed components are determined. According to the corresponding relations between ratio of sedimentary cycle thickness and ratio of astronomical period, the sedimentary cycles related to individual astronomical period are ascertained, and the time limitation of these cycles restricted by absolute geologic age. The case study from Yanchang formation indicates that the time limitation numbers of these cycles classified by detailed components are twice of astronomical periods, that is, taking the astronomical period as classifying basis of datum-cycle sequence classification, the each sedimentary cycle can be divided into two datum-cycle sequences. The research shows that the rational and effective classification and correlation of the datum-cycle sequence can be carried out based on astronomical period, discrete wavelet transformation and spectrum analysis, and the stratigraphic ages are ascertained by restriction of corresponding absolute geological ages. References | Related Articles | Metrics

The Seismic Prospecting Technology for Deep Clastic Non-Structural Trap in Tahe Oilfield QI Li-xin 2009, 30 (4):  515-518.  Abstract ( 66 )   PDF (374KB) ( 268 )   Save With continuous increase of exploratory efforts, the targets for exploration in Tahe oilfield are more and more complex, which are dominated by non-structural reservoirs with buried depth of more than 4 000 meters. Such reservoirs are characterized by low amplitude structure, small sand thickness and large lateral variation, being difficult to identify and evaluate. For these problems, a series of technologies for identification and evaluation of deep clastic non-structural trap in Tahe oilfield is developed, including forward modeling, fine coherent fault interpretation, seismic waveform analysis, seismic attribute acquisition and optimization, seismic-logging inversion, 3D visual geologic object detection, etc., which provide powerful supports for further exploration in Taha oilfield and incremental reserves and production of northwest oilfield company. References | Related Articles | Metrics

Definition and Interpretation for Different Base-Levels in Seismic Data Processing JIA Ming-chen 2009, 30 (4):  519-520+536.  Abstract ( 206 )   PDF (234KB) ( 212 )   Save This paper presents the analyses and discussions of several base-levels definitions, static correction methods and static computations as well as corresponding relations to individual surface structures and velocity fields that are commonly applied in production nowadays. The study shows that the common midpoint (CMP) reference surface is the smooth surface corresponding to the surface elevation without changing relations to the surface structure and velocity. The relations among the time, depth and velocity of vertical seismic profile (VSP) can be corresponded to the stratigraphic relations under CMP reference surface one by one. The methods for correction and computation of VSP's time, depth and velocity based on different base-levels' seismic data and the method for related time- depth conversion and structural mapping are proposed, which provide bases for VSP calibration, time-depth conversion and structural mapping in stage of seismic data processing. References | Related Articles | Metrics

Method for S-Wave Moveout Calculation and Application Based on Conventional Well Logging Information SUN Yu-kai, ZHENG Lei-qing 2009, 30 (4):  521-522.  Abstract ( 112 )   PDF (206KB) ( 444 )   Save Shear-wave information play an important part in reservoir identification, engineering parameter calculation, geophysical prediction, etc. However, few S-wave data collected from the logging information lead to difficulties for the later studies on the reservoir. Taking the lithologic reservoir in Shengbei area of Tuha oilfield as an example, the relations of compensated neutron, compensated density, resistivity curves and the lithology in studying conventional logging data are conducted, by which the S-wave moveout data from existing standard wells are collected, and the model for moveout parameter calculation in this area is developed, in order to provide reference for such a calculation of similar reservoirs. References | Related Articles | Metrics

Preliminary Study on Velocity Modeling for Irregular Surface PAN Yan-mei, LIU Yu-zhu, YANG Kai 2009, 30 (4):  523-525.  Abstract ( 111 )   PDF (352KB) ( 279 )   Save Aiming at the complex geological structures with the topographic relief, complex surface structures and strong velocity contrast in the mountain front area in Xinjiang, the first-arrival waveform inversion is adopted for detailed modeling of surface velocity. The results show that first-arrival waveform inversion can be used to reconstruct the fine details of the surface velocity model. Time-domain waveform inversion is somewhat sensitive to the initial model. The forward modeling indicates that seismic wave propagation is severely affected by the surface structure. The modeling precision, lateral resolution and illumination could be influenced by the irregular topography model with large dip and strong velocity contrast, hence leading to lower degrees of the modeling precision and resolution. References | Related Articles | Metrics

A Microphysical Interpretation for Genetic Mechanism of Coal-Derived Hydrocarbon ZHOU Yan-ru, WANG Wei-min 2009, 30 (4):  526-532.  Abstract ( 129 )   PDF (795KB) ( 407 )   Save In light of the micro-hydrocarbon generation mechanism of organic matter, by means of the electron-resonance in valence-bond theory and the solid energy band in molecular orbital theory, in terms of the organic matter structure characteristic of coal, this paper presents the specific reaction of bonding-electron off-domain and add-hydrogen resonance for the coal-derived hydrocarbon, and makes satisfactory interpretation of the micro-mechanism for coal-derived hydrocarbon. References | Related Articles | Metrics

The Impact of Clay Minerals on Oil-Gas Reservoir ZHAO Xing-yuan 2009, 30 (4):  533-536.  Abstract ( 205 )   PDF (414KB) ( 610 )   Save Clay minerals are closed to petroleum geology and drilling-producing engineering owing to their distribution universality, unique crystal structure and physicochemical property. There are different correlations between different clay minerals and sand porosity and permeability; and there exist differentiations in correlativity or correlation coefficient between the same clay mineral and sand porosity and permeability due to its difference in shape and occurrence. Such a most important and potential factor for causing oil-gas reservoir damages appears the fact that different clay minerals could cause different damages of oil-gas reservoir. It is concluded that taking corresponding and advantageous measures for preventing oil-gas reservoir damages based on available studied results of clay minerals can gain stable and high yields of oil-gas reservoirs or fields. References | Related Articles | Metrics

Controversy of the Origins of Natural Gas in Songliao Basin WEI Zhi-ping, ZHANG Jing-lian, FANG Le-hua, DU Yu-tan 2009, 30 (4):  537-542.  Abstract ( 130 )   PDF (368KB) ( 244 )   Save The origin of natural gas of Xujiaweizi fault depression in Songliao basin is heavily debatable on that account whether it is biogenetic or abiogenetic. There are different interpretations on the origins of natural gas in the nature. The carbon isotopic fractionation can be taken place in Fischer-Tropsch synthesis just like in plants' photosynthesis possibly without indication of reverse distribution of carbon isotope. Fischer-Tropsch reaction under the hydrothermal conditions is very common in the nature, but the kinetic fractionation mechanism of carbon and hydrogen isotopes is not clear. Carbon isotope used for the trace distinguishing of oil-gas sources is still of great uncertainty. The deep crust structures of Songliao basin show that there exists a low velocity-high conductive layer in the mid-crust, in which the mantle fluids enriched with CO2 , H2 could take part in reactions of Fischer-Tropsch synthesis and generate hydrocarbon compounds. Based on this thought, much more natural gases could be explored and discovered in deep Songliao basin (including volcanic rocks, granites and other basement rocks). In addition, giant oil-gas fields could be found out in other domestic basins by such a thought. References | Related Articles | Metrics

Approach to Oil Sand Resource Potentials and Recovery Process in Northwestern Margin of Junggar Basin ZHANG Ming-yu, HE Ai-dong, SHEN Xin-an, HUANG Wen-hua 2009, 30 (4):  543-545.  Abstract ( 133 )   PDF (403KB) ( 383 )   Save The northwestern margin of Junggar basin is of superior conditions in oil sand resources. They are distributed in Hongshanzui- Karamay-Wuerhe areas with features of multiple oil sands (3~14 layers), large thickness (1.5~93.65 m), high oil content (3%~23%), premium oil-sand quality and shallow burial depth, etc., and can be recovered by open-cut mining process and tunnel-based steam injection process. The oil sand resources in this area are of certain commercial values. References | Related Articles | Metrics