985 resultados para sequence stratigraphy


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Application of long-term exploration for oil and gas shows that the reservoir technology of prediction is one of the most valuable methods. Quantitative analysis of reservoir complexity is also a key technology of reservoir prediction. The current reservoir technologies of prediction are based on the linear assumption of various physical relationships. Therefore, these technologies cannot handle complex reservoirs with thin sands, high heterogeneities in lithological composition and strong varieties in petrophysical properties. Based on the above-mentioned complex reservoir, this paper conducts a series of researches. Both the comprehending and the quantitative analysis of reservoir heterogeneities have been implemented using statistical and non-linear theories of geophysics. At the beginning, the research of random media theories about reservoir heterogeneities was researched in this thesis. One-dimensional (1-D) and two-dimensional (2-D) random medium models were constructed. The autocorrelation lengths of random medium described the mean scale of heterogeneous anomaly in horizontal and deep directions, respectively. The characteristic of random medium models were analyzed. We also studied the corresponding relationship between the reservoir heterogeneities and autocorrelation lengths. Because heterogeneity of reservoir has fractal nature, we described heterogeneity of reservoir by fractal theory based on analyzing of the one-dimensional (1-D) and two-dimensional (2-D) random medium models. We simulated two-dimensional (2-D) random fluctuation medium in different parameters. From the simulated results, we can know that the main features of the two-dimensional (2-D) random medium mode. With autocorrelation lengths becoming larger, scales of heterogeneous geologic bodies in models became bigger. In addition, with the autocorrelation lengths becoming very larger, the layer characteristic of the models is very obvious. It would be difficult to identify sandstone such as gritstone, clay, dense sandstone and gas sandstone and so on in the reservoir with traditional impedance inversion. According to the obvious difference between different lithologic and petrophysical impedance, we studied multi-scale reservoir heterogeneities and developed new technologies. The distribution features of reservoir lithological and petrophysical heterogeneities along vertical and transverse directions were described quantitatively using multi-scale power spectrum and heterogeneity spectrum methods in this paper. Power spectrum (P spectrum) describes the manner of the vertical distribution of reservoir lithologic and petrophysical parameters and the large-scale and small-scale heterogeneities along vertical direction. Heterogeneity spectrum (H spectrum) describes the structure of the reservoir lithologic and petrophysical parameters mainly, that is to say, proportional composition of each lithological and petrophysical heterogeneities are calculated in this formation. The method is more reasonable to describe the degree of transverse multi-scale heterogeneities in reservoir lithological and petrophysical parameters. Using information of sonic logs in Sulige oil field, two spectral methods have been applied to the oil field, and good analytic results have been obtained. In order to contrast the former researches, the last part is the multi-scale character analysis of reservoir based on the transmission character of wave using the wavelet transform. We discussed the method applied to demarcate sequence stratigraphy and also analyzed the reservoir interlayer heterogeneity.

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Based on the theories of sequence stratigraphy and sedimentology, as well as comprehensive studies of seismic data, drilling data, core interpretation and setting of this area, the thesis presents an analysis for Mesozoic formation in Dinan uplift. By means of recognizing the boundary of the sequence, dividing and correlating the systems tract, Mesozoic of Dinan uplift is divided into ten sequences and twenty-five systems tracts during the establishment of the sequence framework. In the framework, some sequences are featured by mature systems of lowstand, water-transgression and highstand, while some undeveloped systems of lowstand or highstand. The main sedimentary facies in Mesozoic of Dinan uplift are braided river, meandering river, delta and lake. The braided river was divided into sandy river and rudaceous river by the lithology of the river channel and was divided into dry climate and wet climate condition by the color of the flood plain. Additionally, The concept of “wetland” is put forward for the first time and regarded as the consequence of wet climate. The analysis includes the classification of six types of traps: (1) stratigraphic overlap trap, (2) lithologic trap with updip pinchout, (3) stratigraphic unconformity trap, (4) fault-lithology trap, (5) fault trap, (6) anticlinal trap, and combining with the research of the characteristics and distribution rules for the known reservoir, it draws out that “fault control” is the petroleum accumulation pattern in this area, in which fault is the key element of the transporting system. Finally the thesis concludes the distribution characteristics and optimized some targets for the potential exploration zone.

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The exploration and study in recent years shows that the upper Paleozoic in the east of Ordos Basin possesses major exploration potential, so it is necessary to have a comprehensive and synthetic research in this area. Following the guideline of T.A. Cross’s high resolution sequences stratigraphy and combined with sedimentology, the strata and sequence in the research area are divided and correlated. This paper emphasizes on the reservoir in this area and its major fruits are: Firstly, form the framework of the high sequence stratigraphy through mainly studying on the data of core, well drilling and field section combining. Then, think that the best reservoir formation mainly appears in the middle or lower part of long arising semi-cycle, and focus on A type and C1 middle sequence cycle that contributes to the development of formation. Next, think the sedimentary source mainly comes from the epimetamorphic crystalline basement in the north of the Ordoes Basin through analyzing depositional background, researching on sandstone petrography, distribution characteristics of the sedimentary system as well as researching on heavy mineral combination characteristics. Fourthly, give priority to Zizhou-Qingjian area for the first time and gain seven lithofacies paleography maps in the No.2 member of Shanxi and the No.8 member of Shihezi through using the method of isochronal lithofacies paleogeography mapping, then bring forth that Sh2 is mainly developed a type I sequence under the margin of ramp lake-basin background. Fifthly, through researching on the characteristics of reservoir petrography and diagenesis, think that all researched areas experienced compaction and cementation, and there is different types of rocks, only little of the primary pores that are made up of litharenite and lithoclastic quartz sandstone is left, while in lithoclastic quartz sandstone, there are still many primary pores Sixthly, through studying on pore types, microstructure, as well as physical property on the key formation, think that the researched area mostly appears typical low pore, low porosity and permeability, which mainly result from sedimentary and diagenesis. Lastly, through researching on classified evaluation in the key formation, productivity analysis, and combing with reservoir distribution, the researched area is divided into three parts, and think that exploration should be emphasized on formation I and II. The characteristics of sandstones distribution in Sh23 member, gas formation distribution and open flow capacity of exploitation well are all consistent properly with the results of reservoir comprehensive evaluation in this thesis proved by the gas production development in 2006.

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The Ordos Basin is a large-scale craton superimposed basin locating on the west of the North China platform, which was the hotspot of interior basin exploration and development. Qiaozhen oil field located in the Ganquan region of south-central of Ordos Basin. The paper is based on the existing research data, combined with the new theory and progress of the sedimentology, sequence stratigraphy, reservoir sedimentology, petroleum geology, etc, and analyzes systematically the sedimentary and reservoir characteristics in the chang2 and chang1 oil-bearing strata group of Yanchang formation On the basis of stratigraphic classification and comparison study, the strata chang2 and chang1 were divided into five intervals. Appling the method of cartography with single factor and dominance aspect, we have drawn contour line map of sand thickness, contour line map of ratio between sand thickness and stratum thickness. We discussed distribution characteristics of reservoir sand body and evolution of sedimentary facies and microfacies. And combining the field type section , lithologic characteristics, sedimentary structures, the sedimentary facies of single oil well and particle size analysis and according to the features of different sequence, the study area was divided into one sedimentary facies、three parfacies and ten microfacies. The author chew over the characteristics of every facies, parfacies and microfacies and spatial and temporal distribution. Comprehensive research on petrologic characteristics of reservoir , diagenesis types, pore types, distribution of sand bodies, physical properties, oiliness, reservoir heterogeneities, characteristics of interlayer, eventually research on synthetic classifying evaluation of reservoir.The reservoir is classified four types: Ⅰ、Ⅱ、Ⅲ、Ⅳ and pore type, fracture-porosity type. Take reservoir's average thickness, porosity, permeability, oil saturation and shale content as parameters, by using clustering analysis and discriminant analysis, the reservoir is classified three groups. Based on the evaluation, synthetizing the reservoir quality, the sealing ability of cap rock, trap types, reservoir-forming model ,in order to analyze the disciplinarian of accumulation oil&gas. Ultimately, many favorable zones were examined for chang23,chang223,chang222,chang221,chang212,chang12,chang11 intervals. There are twenty two favorable zones in the research area. Meanwhile deploy the next disposition scheme.

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Based on outcrop, borehole, seismic and regional geological data, the sequence stratigraphy, sedimentary facies of the Triassic in the western margin of the Zhugaer basin was studied, and favorable exploration target was forecasted. The major achievements include: (1) the Triassic in the western margin of the Zhugaer basin can be divided into 1 second-order sequence and 5 third-order sequences, which are, in ascending order, TSQ1, TSQ2, TSQ3, TSQ4, and TSQ5. TSQ1 is equivolent to Baikouquan formation, TSQ2 is equivolent to lower Kelamayi formation, TSQ3 is equivolent to upper Kelamai formation, TSQ4 is equivolent to lower and middle Baijiantan formation, and TSQ5 is equivolent to upper Baijiantan formation. Each sequence is divided into transgressive and regressive system tracts. Thus the sequence correlation framework is established. (2) The factors controlling development of sequences are analyzed, and it is believed that tectonic is the major controlling factor. Model of sequence development is summarized. (3)Through study on sedimentary facies, 6 types of facies are recognized: alluvial fan, fan delta, braided river, braided delta, delta and lake. Their microfacies are also recognized. In this study, it is proposed that the upper and lower Kelamayi formation(TSQ2、 TSQ3)is deposited by braided river instead of alluvial fan. This conclusion is of important theoretical and practical significance.(4) The sedimentary facies map of each sequence is compiled, and the sedimentary facies developed in each sequence is determined. In TSQ1, the sedimentary facies developed is alluvial fan and fan delta. In TSQ2, the sedimentary facies developed is mainly alluvial fan and fan delta in the north, and braided river and braided delta in the south. In TSQ3, the sedimentary facies developed is mainly braided river and braided delta. In TSQ4, the sedimentary facies developed is mainly braided delta in the north, and meandering delta in the south. In TSQ5, the sedimentary facies developed is mainly braided river and braided delta. (5) In the framework of sequence stratigrahpy, favorable areas for concealed traps are forecasted, and different types of traps are developed in different system tracts. (6) Favorable areas for future exploration are predicted.

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Ordos basin is a large-scale craton overlapping basin, which locates in western North China platform and possesses abundant hydrocarbon resources. Ansai area in 2007 to extend the head of Chang10 of Yangchang Formation has made breakthrough progress in the region, long a high of Gao52 was Chang10 industrial oil flow, for oil exploration Ansai Oil Field opened a new chapter. in 2008, high of Gao52, Wang519, Gao34 producing wells area of building and found the existence of Chang10 great potential for the discovery of Chang10 Reservoir, Ansai Oil Field for a new direction, showing a good exploration development prospects.The study of occurrence and distribution features of hydrocarbon should be made by new theories and evolutions of sedimentology, sequence stratigraphy, reservoir sedimentology and petroleum geology form different angles on the base of regional geology background. Ansai Oil Field is in mid Shanbei Slope, which is a considerable producing zone of Ordos basin. Chang10 of Yangchang Formation is an important oil-bearing series, which sedimentary formation was formed in Indosinian orogeny, Late Triassic, sedimentary background is a momentary uplifting in Ordos basin, and exploration and exploitation of hydrocarbon in this area is very important. To further descripte disciplinarian of accumulation hydrocarbon, carefully study on sedimentary facies, reservoir type and disciplinarian of accumulation hydrocarbon of Chang10 of Yangchang Formation in study area is needed. By collecting date of field profile, outcrop, core and many other geological, through sedimentary and oil geological analysis, sedimentary facies types were identified, distributing of sedimentary facies and extension of sand body were analyzed too. Finally, the main controlling factors of hydrocarbon and the favorable areas were found out by deeply studying sedimentary system and disciplinarian of accumulation oil&gas in Chang10 of Yangchang Formation, Late Triassic in Ansai Oil Field. Chang10 of Yangchang Formation is main study formation, which is divided into three members (Chang101, Chang102 and Chang103), Chang101 is subdivided into three (Chang1011, Chang1012and Chang1013) reservoirs. By defining Layered borderline between every member and detailed describing rock and electro characteristic, member zonation become more reasonable and accurate also sedimentary facies and disciplinarian of accumulation oil&gas in study area are confirmed Through researching sedimentary facies, reservoir sand and hydrocarbon migration, accumulation, distribution, hydrocarbon accumulation models of Chang10 of Yangchang Formation in study area is pointed out, which is lithologic hydrocarbon reservoir and tectonic-lithologic hydrocarbon reservoir. Different play is formed by different processes and factors. Through analysis of reservoir property, trap type and accumulation model, several favorable exploration areas can be found out in Chang 10 reservoirs (Chang1011, Chang1012and Chang1013) of the Ansai Oil Field.

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Integrating geology, core, well-logging, experimental data, and production data, with the guide of sequence stratigraphy, sedimentology, reservoir exploitation geology and other disciplines’ theories, combinating the sequence stratigraphy and Maill’s reservoir architectures concepts and theories, the research and analysis methods of non-marine fan-delta reservoir architectures are systemly set out. And the correspondence of reservoir structures, sedimentology and reservoir geology is established. An integral and systematical research approach and theory and conception of reservoir architecture is developed, which enriched the reservoir research theory. Considering the requirement to the reservoir research in different development phase, the six classification systems of reservoir architectures are brought up. According to different reservoir’s connection and location of Ek different levels of reservoir architecture, 3 types, 20 kind architectures styles are summarized. The research about undisturbed reservoir characterization is launched, through analyzing reservoir characterization to pour water to the different reservoirs of Kongnan region, the changing regular pattern of reservoir quality during pouring water process is summarized. Combined with the actual zone data, inner-well reservoir geometry relationship of injection-production model is designed, and the models of development process are dynamic simulated. In view of seven laboratory samples of 3 types, six order architecture unit of braided stream, fan-delta and nearshore subsea apron in Kongnan region, the remaining oil distribution model is determined. Using the geo-statistics methods dissect the key regions, the tectono-stratigraphical model and the reservoir parameters model are established. The distribution of the characteristics of the underground reservoir is quantitatively described. Based on the reservoir research, carrying out the development of different characteristics of reservoir, the development pattern and countermeasures are determined. The relationships between reservoir structure levels and reservoir development stages are summed up, the relationships between architecture unit of different levels and exploration develop stages are determined.

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Lower member of the lower Ganchaigou Formation in the southwestern of Qaidam Basin is one of the main targeted exploration zones. With the advancement of exploration, the targets are gradually switching into the lithologic reservoirs and it is urgent to gain the more precise research results in distribution of sedimentary facies and sandstones. Guided by the theory of sequence stratigraphy and sedimentology as well as on the basis of many logging data, drillings, seismic data and chemical tests, the paper comprehensively analyzes the sedimentary facies and sandstones in the lower member of lower Ganchaigou Formation in the southern of Chaixi. According to the identification marks of the key interface in sequence stratigraphy, the key interfaces in lower member of lower Ganchaigou Formation in the southwestern of Qaidam Basin are identified as two third-order sequences SQ1、SQ2. By calibrating the synthetic seismogram, the seismic sequence, well drilling and logging sequences are united. Based on the works above, this paper chooses seven primary cross-sections and builds connecting-well stratigraphic correlation of seven main connecting-well sections. Ultimately, the high-resolution sequence stratigraphic frameworks in the lower member of the lower Ganchaigou Formation, which are uniform to logging and seismic data, are figured out. In terms of study on each sequence features, the main style of the base-level cycle overlay which forms the third-order sequence is confirmed. It contains asymmetric “becoming deep upward” style and symmetry style. Researching on the spreading characters of sequence stratigraphy indicates that SQ1 and SQ2 are rather thicker near northwest well Shashen 20 and Shaxin1 while they are quite thiner near Hongcan 1, Yuejin, Qie 4 and Dong8-Wu3, and the thickness of SQ1 is thicker than SQ2.Based on the deep analysis of the marks for depositional facies, it is proposed that the lake facies and braid river deltas facies mainly occurred in study areas. Besides, the sorts of sub-facies and micro-facies model are divided and described. Under the control of high-resolution sequence stratigraphic framework, three source directions from Arlarer Mountain、Qimantage Mountain and Dongchai Mountain are identified by using the features of heavy mineral assemblage and paleogeomorphy. In addition, regularities of distribution sedimentary facies in sequence stratigraphic framework are studied in accordance with research thinking of the "point" (single well) "line" (section) "face" (plane). In the stage of lower member in the lower Ganchaigou Formation in the southwestern of Qaidam Basin, it is at the early phrase of evolution of the lake basin with the gradual outspread and the rise of the lake level. Combined with physical analysis of reservoir sands formed in different sedimentary environment, the paper studies the style of favorable sandstone bodies that are underwater distributary channel of braided rive delta front, coarse sand in mouth bar and the sand body in sand flat of shore-shallow lacustrine facies. Finally, this article comprehensively analyzes the distribution relationship between sedimentary facies and favorable sandstone body and proposes the ideas that sequence SQ1 Yuejin area, well east 8-wu3 area, well qie4-qie1 area and well hongcan2 area are distributed areas of favorable sandstone.

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Xuanlong-type Hematite Deposits, distributed in Xuanhua and Longguang area in Hebei province and hosted in the Changchengian Chuanlinggou Formation of Mesoproterozoic, is an oldest depositional iron deposit characterized by oolitic and stromatolitic hematite and siderite. This thesis made an systematic study of its sedimentary, sedimentology, geochemistry, mineralogy and sequence stratigraphy. Based on above, the mechanism and background of biomineralization are discussed. There are four types of hematite ores including stromatolite, algal oolite, algal pisolite and oncolite. Based on detailed study on ore texture, the authors think both algal oolite and algal pisolite ores are organic texture ores, and related to the role of microorganisms. The process of blue-green algae and bacteria in the Xuanlong basin absorbing, adsorbing and sticking iron to build up stromatolite is the formation process of Xuanlong-type hematite deposit. Researches on ore-bearing series and ore geochemistry show that the enrichment of elements is closely related to the microorganism activities. Fe_2O_3 is enriched in dark laminations of stromatolite with much organic matter and SiO_2 in light laminations with detrital matters. The trace elements, especially biogenic elements, including V, P, Mo are enriched in ores but relatively low in country rocks. The paper also demonstrates on the sequence stratigraphy of hematite deposits and five sequences and twelve systems are divided. The characteristics of sequence stratigraphy show that the deposit-forming location has obviously selectivity and always exists under a transgressive setting. The oxygen isotope in hematite is about -2.2~5.7‰, which is similar to that of Hamlys iron formation of Australia but more negative than that of volcanic or hydrothermal iron deposits characterized by high positive values. The calculation by the result of oxygen isotope analysis shows that the temperature of ancient sea water was 48.53℃. The negative value of carbon isotope from siderite indicates its biogenic carbon source. Meanwhile, the occurrence of seismite in the ore-beds, which indicates the formation of hematite deposits is associated with frequent shock caused by structural movement such as distal volcano or ocean-bottom earthquake etc, show the occurrence of hematite deposits is eventual, not gradual. In shorts, Xuanlong-type hematite deposits were the result of interaction among geological setting of semi-isolated Xuanglong basin, favorable hot and humid climate condition, abundant iron source, microorganism such as algae and bateria as well as the fluctuation of the sea level.

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The biothermocatalytic transitional zone gas is a new type of natural gas genetic theory, and also an clean, effective and high quality energy with shallow burial depth, wide distribution and few investment. Meanwhile, this puts biothermocatalytic transitional zone gas in important position to the energy resource and it is a challenging front study project. This paper introduces the concept, the present situation of study and developmental trend about biothermocatalytic transitional zone gas in detail. Then by using heat simulating of source rocks and catalysis mechanism analysis in the laboratory and studying structural evolution, sedimentation, diagenesis and the conditions of accumulation formation and so on, this paper also discusses catalytic mechanism and evolutionary model of the biothermocatalytic transitional zone gas formation, and establishes the methods of appraisal parameter and resources prediction about the biothermocatalytic transitional zone gas. At last, it shows that geochemical characteristics and differentiated mark of the biothermocatalytic transitional zone gas, and perfect natural gas genetic theory, and points out the conditions of accumulation formation, distribution characteristics and potential distribution region on the biothermocatalytic transitional zone gas m China. The paper mainly focuses on the formation mechanism and the resources potential about the biothermocatalytic transitional zone gas. Based on filed work, it is attached importance to a combination of macroscopic and microcosmic analysis, and the firsthand data are obtained to build up framework and model of the study by applying geologic theory. Based on sedimentary structure, it is expounded that structural actions have an effect on filling space and developmental cource of sediments and evolution of source rocks. Carried out sedimentary environment, sequence stratigraphy, sedimentary system and diagenesis and so on, it is concluded that diagenesis influences developmental evolution of source rocks, and basic geologic conditions of the biothermocatalytic transitional zone gas. Applying experiment simulating and catalytic simulating as well as chemical analysis, catalytic mechanism of clay minerals is discussed. Combined diagenecic dynamics with isotope fractionation dynamics, it is established that basis and method of resource appraisal about the biothermocatalytic transitional zone gas. All these results effectively assess and predict oil&gas resources about the biothermocatalytic transitional zone gas-bearing typical basin in China. I read more than 170 volumes on the biothermocatalytic transitional zone gas and complete the dissertation' summary with some 2.4 ten thousand words, draw up study contents in some detail and set up feasible experimental method and technologic course. 160 pieces of samples are obtained in oilfield such as Liaohe, Shengli, Dagang and Subei and so on, some 86 natural gas samples and more than 30 crude oil samples. Core profiles about 12 wells were observed and some 300 geologic photos were taken. Six papers were published in the center academic journal at home and abroad. Collected samples were analysised more than 1000 times, at last I complete this dissertation with more than 8 ten thousand words, and with 40 figures and 4 plates. According to these studies, it is concluded the following results and understandings. 1. The study indicates structural evolution and action of sedimentary basin influence and control the formation and accumulation the biothermocatalytic transitional zone gas. Then, the structural action can not only control accommodation space of sediments and the origin, migration and accumulation of hydrocarbon matters, but also can supply the origin of energy for hygrocarbon matters foramtion. 2. Sedimentary environments of the biothermocatalytic transitional zone gas are lake, river and swamp delta- alluvial fan sedimentary systems, having a warm, hot and humid climate. Fluctuation of lake level is from low to high., frequency, and piling rate of sedimentary center is high, which reflect a stable depression and rapidly filling sedimentary course, then resulting in source rocks with organic matter. 3. The paper perfects the natural gas genetic theory which is compound and continuous. It expounds the biothermocatalytic transitional zone gas is a special gas formation stage in continuous evolutionary sequence of organic matter, whose exogenic force is temperture and catalysis of clay minerals, at the same time, having decarbxylation, deamination and so on. 4. The methodology is established which is a combination of SEM, TEM and Engery spectrum analysis to identify microstructure of crystal morphology about clay minerals. Using differential thermal-chromatographic analysis, it can understand that hydrocarbon formation potential of different typies kerogens and catalytic method of all kinds of mineral matrix, and improve the surface acidity technology of clay minerals measured by the pyridine analytic method. 5. The experiments confirm catalysis of clay minerals to organic matter hygrocarbon formation. At low temperature (<300 ℃), there is mainly catalysis of montmorillonite, which can improve 2-3 times about produced gas of organic matters and the pyrolyzed temperature decreased 50 ℃; while at the high temperature, there is mainly catalysis of illite which can improve more than 2 times about produced gas of organic matters. 6. It is established the function relationship between organic matter (reactant) concentration and temperature, pressure, time, water and so on, that is C=f (D, t). Using Rali isotope fractionation effect to get methane isotope fractionation formula. According to the relationship between isotope fractionation of diagenesis and depth, and combined with sedimentary rate of the region, it is estimated that relict gas of the biothermocatalytic transitional zone gas in the representative basin. 7. It is revealed that hydrocarbon formation mechanism of the biothermocatalytic transitional zone gas is mainly from montmorillonite to mixed minerals during diagenesis. In interlayer, a lot of Al~(3+) substitute for Si~(4+), resulting in a imbalance between surface charge and interlayer charge of clay minerals and the occurrence of the Lewis and Bronsted acid sites, which promote to form the carbon cation. The cation can form alkene or small carbon cation. 8. It is addressed the comprehensive identification mark of the biothermo - catalytic transitional zone gas. In the temproal-spatial' distribution, its source rocks is mainly Palaeogene, secondly Cretaceous and Jurassic of Mesozoic, Triassic, having mudy rocks and coal-rich, their organic carbon being 0.2% and 0.4% respectively. The vitrinite reflection factor in source rocks Ro is 0.3-0.65%, a few up to 0.2%. The burial depth is 1000-3000m, being characterized by emerge of itself, reservoir of itself, shallow burial depth. In the transitional zone, from shallow to deep, contents of montmorillonites are progressively reduced while contents of illites increasing. Under SEM, it is observed that montmorillonites change into illite.s, firstly being mixed illite/ montmorillonite with burr-like, then itlite with silk-like. Carbon isotope of methane in the biothermocatatytic transitional zone gas , namely δ~(13)C_1-45‰- -60 ‰. 9. From the evolutionary sequence of time, distribution of the biothermocatalytic transitional zone gas is mainly oil&gas bearing basin in the Mesozoic-Neozoic Era. From the distribution region, it is mainly eastern stuctural active region and three large depressions in Bohaiwang basin. But most of them are located in evolutionary stage of the transitional zone, having the better relationship between produced, reservoir and seal layers, which is favorable about forming the biothermocatalytic transitional zone gas reservoir, and finding large gas (oil) field.

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The Dongying depression, located in the northern part of the jiyang Sag in the Buohaiwan Basin, comprises one of the major oil-producing bases of the Shengli oil-field. The prediction and exploration of subtle or litho1ogical oil traps in the oil-field has become the major confronted target. This is also one of the frontier study areas in the highly-explored oil-bearing basins in East China and abroad. Based on the integrated analysis of the geological, seismic and logging data and the theories of sequence stratigraphy, tectono-stratigraphy and petroleum system, the paper has attempted to document the characteristics of the sequence stratigraphic and structural frameworks of the low Tertiary, the syndepositional faults and their control on deposition, and then to investigate the forming conditions and distribution of the tithological oil traps in the depression. The study has set up a set of analysis methods, which can be used to effectively analysis the sequence stratigraphy of inland basins and predict the distribution of sandstone reservoirs in the basins. The major achievements of the study are as follows: 1. The low Tertiary can be divided into 4 second-order sequences and 13 third-order sequences, and the systems tracts in the third-order sequences have been also identified based on the examination and correction of well logging data and seismic profiles. At the same time, the parasequences and their stacking pattern in the deltaic systems of the third member of the Shahejie Formation have been recognized in the key study area. It has been documented that the genetic relation of different order sequences to tectonic, climatic and sediment supply changes. The study suggested that the formation of the second-order sequences was related to multiple rifting, while the activity of the syndepositional faults controlled the stacking pattern of parasequences of the axial deltaic system in the depression. 2. A number of depositional facies have been recognized in the low Tertiary on the basis of seismic facies and well logging analysis. They include alluvial fan, fan delta or braided delta, axial delta, lowstand fan, lacustrine and gravity flow deposits. The lacustrine lowstand fan deposits are firstly recognized in the depression, and their facies architecture and distribution have been investigated. The study has shown that the lowstand fan deposits are the important sandstone reservoirs as lithological oil traps in the depression. 3. The mapping of depositional systems within sequences has revealed the time and special distrbution of depositional systems developed in the basin. It is pointed out that major elastic systems comprise the northern marginal depositional systems consisting of alluvial fan, fan delta and offshore lowstand fan deposits, the southern gentle slope elastic deposits composed of shallow lacustrine, braided delta and lowstand fan deposits and the axial deltaic systems including those from eastern and western ends of the depression. 4. The genetic relationship between the syndepositional faults and the distribution of sandstones has been studied in the paper, upper on the analysis of structural framework and syndepositional fault systems in the depression. The concept of structural slope-break has been firstly introduced into the study and the role of syndepositional faults controlling the development of sequence architecture and distribution of sandstones along the hinged and faulted margins have been widely investigated. It is suggested that structural styles of the structural slope-break controlled the distribution of lowstand fan deposits and formed a favorable zone for the formation of lithological or structure-lithological oil traps in the basin. 5. The paper has made a deep investigation into the forming condition and processes of the lithological traps in the depression, based the analysis of composition of reservoir, seal and resource rocks. It is pointed out that there were two major oil pool-forming periods, namely the end of the Dongying and Guangtao periods, and the later one is the most important. 6. The study has finally predicted a number of favorable targets for exploration of lithologieal traps in the depression. Most of them have been drilled and made great succeed with new discovered thousands tons of raw oil reserves.

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The development petroleum geology has made people from studying and studying and predicting in statically and respectively the pool-forming conditions of an area such as oil source bed, reservoir, overlying formation, migration, trap and preservation, etc. to regarding these conditions as well as roles of generation, reservation and accumulation as an integrated dynamic evolution development system to do study .Meanwhile apply various simulating means to try to predict from quantitative angle. Undoubtedly, the solution of these questions will accumulate exploration process, cut down exploration cost and obtain remarkable economic and social benefits. This paper which take sedimentology ,structural geology and petroleum geology as guides and take petroleum system theory as nucleus and carry out study thinking of beginning with static factor and integration of point and face as well as regarding dynamic state factor as factor and apply study methods of integration of geology, Lab research and numerical modeling proceed integrated dissect and systematic analysis to GuNan-SanHeCun depression. Also apply methods of integration of sequence stratigraphy, biostratigraphy, petrostratigraphy and seismic data to found the time-contour stratigraphic framework and reveal time-space distribution of depositional system and meantime clarify oil-source bed, reservoir and overlying distribution regular patterns. Also use basin analysis means to study precisely the depositional history, packed sequences and evolution. Meanwhile analyze systematically and totally the fracture sequence and fault quality and fault feature, study the structural form, activity JiCi and time-space juxtaposion as well as roles of fault in migration and accumulation of oil and gas of different rank and different quality fault. Simultaneously, utilize seismic, log, analysis testing data and reservoir geology theory to do systematic study and prediction to GuNan-SanHeCun reservoir, study the reservoir types macroscopic distribution and major controlling factors, reservoir rock, filler and porosity structural features as well as distribution of reservoir physical property in 3D space and do comprehensive study and prediction to major controlling and influential factors of reservoir. Furthermore, develop deepingly organic geochemistry comprehensive study, emphasis on two overlaps of oil source rock (ESI, ES3) organic geochemistry features, including types, maturity and spatial variations of organic matter to predict their source potential .Also apply biological marks to proceed oil-to-source correlation ,thereby establish bases for distribution of petroleum system. This study recover the oil generation history of oil source rocks, evaluate source and hydrocarbon discharge potential ,infer pool-forming stages and point out the accumulation direction as well as discover the forming relations of mature oil-source rock and oil reservoir and develop research to study dynamic features of petroleum system. Meanwhile use systematic view, integrate every feature and role of pool forming and the evolution history and pool-forming history, thereby lead people from static conditions such as oil source bed, reservoir, overlying formation, migration, trap and preservation to dynamically analyzing pool-forming process. Also divide GuNan-SanHeCun depression into two second petroleum system, firstly propose to divide second petroleum system according to fluid tress, structural axis and larger faults of cutting depression, and divide lower part of petroleum system into five secondary systems. Meanwhile establish layer analysis and quantitative prediction model of petroleum model, and do quantitative prediction to secondary petroleum system.

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Jurassic is an important hydrocarbon-bearing formation in Junggar Basin. Analyzing in strata sequence stratigraphy and hydrocarbon formation has both theoretical and practical values. First of all, strata sequence stratigraphy of continental facies is a new development and supplement in the theory of stratigraphic geology. Stratum of continental facies, unlike sea facies, has rich sup-plements, rapid facies changes, and was influenced slightly by sea level changes. The structural background and sedimentary environment of the basin in west China are greatly different from those of the basins in east China. So it is important to build the patterns of strata sequence stratigraphy in west China basins. Secondly, it is also of significance to find out all kinds of traps, for the dominant types are structural ones so far. After 50 years exploration, the stratigraphic or litholigic traps have become the main concern. This desertation is mainly focused on establishing the isochronal strtaum frame for Junggar Basin to show the evolvement characters of the basin sediment system and the regionalstuctrue background. By analyzing the conditions and patterns of the regional oil and gas bearing formations with typical cross-sections, we have established the patterns of sedimentary conditions for different reserviors. By authur's study, several fruitful results have been obtained in the following: Strata sequence frame and evolvement characteristics of Jurassic: By studing strata sequence, Jurassic has been divided into 2 second rank strata sequences and 3 third rank strata sequences based on the interface unconformities. Only 2 fourth rank strata sequences were grouped in BaDaoWan group. Also different seismic facies and sediment units have been recognized with the establishment of the of sediment system model. The oil-gas system characteristics in Jurassic: We conclude that hydrocar bon resources have the best oil potential. Potential of coal, carbonaceous and dark mudstone were reduced in turn. In this thesis we have made the evaluation of three hydrocarbon sources and the distribution oil-gas resource, and studied the potentials of hydrocarbon and evolvement for each kind of micro-component of the two main resource rocks. Prediction of paleo-temperature: In Junggar basin the evolvement of paleo-ground temperature can be divided into three stages. From Carboniferous to early Permian grads of ancient ground temperature was 8-5 ℃/100m, 5-3 ℃/100m from later period of Permian to end Trias, 3-2 ℃/100m from Jurassic to early Tertiary. Patterns of Jurassic hydrocarbon-bearing reserviors: There were two kinds of hydrocarbon source of Permian and Jurassic. They form different hydrocarbon - bearing systems. Six fundamental hydrocarbon - bearing trap modeS have been established. Directions for later exploration: There were two kinds of regional belts in Jurassic, One is structural belt caused by Yanshan and Ximalaya process, and the other was the stratum one caused by paleostructural rises.

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More and more exploration practises and research results prove that deep-water turbidites and slump turbidites in abrupt slope belt as well as slump turbidites in deposit center are favorable places to find subtle reservoirs. Based on sedimentology, sequence stratigraphy, tectonics and petroleum geology and with the tool of computer, this paper focused a set of questions such as the forming mechanism and m&a of turbidite reservoir in Dongying Sag, and obtained a systematic research result from available information of geology, seismic survey, well logging and testing, etc. Since the structural pattern and tectonic stress are controlling factors on distribution of turbidite reservoirs, deep-water sequence and shallow-water sequence have close relation with various turbidites. The author primarily disclose the regular pattern of the turbidites in the abrupt slope trouth, and predict that the abrupt slope is mainly connected to near-bank slump turbidite fans and deep-water turbidite fans; whereas the depocenter area usually developed with front delta slump fans. According to this, seismic-geology models corresponding to various deposit systems can be set up as a principle for predicting the turbiditea in faulted lacustrine basins. Based on comprehensive study of the turbidite reservoir forming condition and main controlling factors, a differential accumulation model and a multiple migration&accumulation model were also set up for abrupt slope turbidities. Referenced the m

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The north steep slope zone of Dongying Depression has great potential in oil resource and as the usage of 3-d seismic data in the last decade, the exploration of oil and gas has get into the stage of sandy glavel body lithological oil-gas pool exploration. In this thesis, writer take the north steep slope zone of Dongying Depression as target area and take Sha-III and Sha-[V Menber as purpose stratum, study on sequence stratigraphy, depositional system, reservoir description, emphasesing on analyzing of forming of lithological oil-gas pool, especially the dynamics principle of oil and gas preliminary movement from the source rock to the reservoir form lithological oil-gas pools. The aim of this work is to give some quantitatively explanation for the mechanism of lithological oil-gas pool forming, and set up the theory of pool form with characteristic terrestrial faulted basin. There are main conclusions and views as follow. 1. Applying with principle of sequence stratigrapgy, according to the depositional cycles of Dongying Depression, the sequence stratigraphical partition of Tertiary was finished, stressing on dismembering Sha-III and Sha-IV Menber as 5system tracts. 2. The structure of Dongying Depression especially of the north steep slope zone has accomplished, including the analyzing the structural cortroling to depositional condition of the north steep slope zone of Dongying Depression, discussed relationship between the structure of the north steep slope zone and the pool-forming. 3. The horizontal and vertical exchanges of ancient climates and ancient physiognomy of the all stratum units and studies on characteristic of depositional system distribution have been finished, found that there are five depositional systems in the north steep slope zone of Dongying Depression as fluvial, delta (tan-delta), sub-water fluvial fan lacustrine, gravitive flow, and seven formations of sandy glavel body, and forecasting of all kinds of sandy glavel body has been made. 4. Seismic stratigraphy and log stratigraphy have been made, described and forecasted all kinds of reservoir of objective stratum by means of physical geography method, setup a series means of sandy glavel body description suit to target area. 5. The pool-forming system has been studied, analyzing all the elements in petroleum sub-system of Sha-III and Sha-IV Menber of Dongying Depression with view of source controlling, estimated the petroleum system applying source rock potential index combining with distribution ofreservior. 6.Through studying types of pool, the controlling factors of pool-forming of sandy glavel body were discussed by deposition stages, formation types, structure ect. as a conclusion that the characteristics of pool forming in the north steep slope zone of Dongying Depression are, the controlling factor of the pools is mainly lithology, petrophysics of oil sands vary greatly, with a large heterogeneity, all kind of reservoir with different formation has different pool-forming conditions, and as a result, formed various pools of sandy glavel body along the steep slope with regular combination, distribution and constituted the multiple petroleum accumulative pattern. 7. It's the first time to cauculate and estimate the fluid pressure in source rock of Dongying Depression, set up the stratum fluid pressure in Dongying Depression, and firstly use equivalent charging pressure and reservoir forming index to quantitatively evaluate the pool-forming condition of lithological pool.8. Above all studies, follow up the scent of the exploration combined with practice a lot of explorative targets were found, and got geat economic and social benefit.