湖南、广西泥盆纪硅岩地球化学与沉积构造背景

During the Devonian, a complicated carbonate platform-basin configuration was created through transtensional rifting in the context of opening of Devonian South China Sea; extensive bedded chert, commonly interbedded with tuffaceous beds, occurred in the narrow, elongate interplatform basins (or troughs) in South China, where they occurred earlier (Early Devonian) in southern Guangxi and later (early Late Devonian) in northern Guangxi-south central Hunan. In order to unravel the origin and distribution of the bedded chert successions, and their relationships to basement faulting activities during the opening of the Devonian South China Sea, studies of element (major, minor and REE) geochemistry and Rb-Sr, Sm-Nd isotopic systematics are carried out upon the chert deposits. These chert deposits commonly have high SiO2 contents and (average 94.01%) and low TFe2O3 (average 0.55%), together with other geochemical parameters, suggestive of both biogenic and hydrothermal origins. However, Fe/Ti ratio are high along the elongate interplatform basins(troughs) to the northwest along Wuxiangling-Zhaisha-Chengbu, and to the southeast along Xiaodong-Mugui-Xinpu, suggesting relatively intense hydrothermal activities there. They generally contain very low total REE contents (∑REE average 31.21ug/g) with mediate negative Ce anomalies (mean Ce/Ce*=0.83) and low Lan/Cen values (average 1.64), indicating an overall continental margin basin where they precipitated. The northward increases in Ce/Ce* values, particularly along the elongate troughs bounded both to the east and west of the Guangxi-Huanan rift basin, suggest a northward enhancement of terrigenous influences, thereby reflecting a gradual northward propagation of open marine setting. Generally low positive Eu anomalies in the chert, except for the apparently high Eu anomalies in the chert from Chengbu (Eu/Eu* up to 4.6), suggest mild hydrothermal venting activities in general, except for those at Chengbu. The initial 87Sr/86Sr (0) ratios of chert generally vary from 0.712000 to 0.73000 , suggesting influences both from terrigenous influx and seawater. The Nd isotopic model ages (tDM or t2DM) and initial εNd (0) values of chert vary mostly from 1.5 to 2.1 Ga, and from –16 to –21, respectively, implying that the silica sources were derived from the provenances of the Palaeoproterozoic crust relics at depth. The high εNd (0) values of chert (-0.22 to 14.7) in some localities, mostly along the elongate troughs, suggest that silica sources may have been derived from deeper-seated mantle, being channeled through the interplate boundary fault zones extending downwards to the mantle. At Wuxiangling, Nanning, chert occurs extensively from the Emsian through the Frasnian strata, both U/Th ratios and tDM ages of chert reached up to a maximum in the early Frasnian corresponding to the extensive development of chert in South China, pointing to a maximum extensional stage of Devonian South China basin, which is supported by the Ce/Ce* values as is opposed to the previous datasets as the coeval minimum values.

油气输导体系研究及应用─以准噶尔盆地东部白家海凸起侏罗系为例

Baijiahai uplift is an important hydrocarbon accumulation belt in eastern Jungger Basin, on which Cainan oilfield and lithologic hydrocarbon reservoir named Cai 43 have been discovered and both of them share the same target formation of Jurassic. However, in the subsequent exploration at this region, several wells that designed for lithologic traps of Jurassic were eventually failed, and that indicates the controlling factors of lithologic reservoir distribution are far more complicated than our previous expectation. This dissertation set the strata of the Jurassic in well Cai 43 region as the target, and based on the integrated analysis of structure evolution、fault sealing ability、simulations of sedimentary microfacies and reservoir beds���distribution analysis of high porosity-high permeability carrier beds���drive forces of hydrocarbons、preferential conduit system and conduit model as well as critical values of the reservoir physical properties for hydrocarbon charging, a special method that different from the conventional way to predict favorable lithologic traps was established. And with this method the controlling factors of the hydrocarbon reservoirs formation are figured out, and further more, the favorable exploration targets are point out. At Baijiahai uplift, fault plays as a crucial factor in the process of the hydrocarbon reservoir formation. In this study, it is found out that the availability of a fault that work as the seal for oil and gas are different. The critical value of the lateral mudstone smear factor (Kssf), which is used to measure the lateral sealing ability of fault, for oil is 3.9 while that for gas is 2.1; and the critical value of vertical sealing factor (F), which similarly a measurement for the vertical sealing ability of fault, for oil is 7.3 while that for gas is 5.1. Dongdaohaizi fault belt that possessed well lateral sealing ability since later Cretaceous have bad vertical sealing ability in later Cretaceous, however, it turns to be well now. Based on the comparison of the physical properties that respectively obtained from electronic log calculating、conventional laboratory rock analysis and the additive-pressure bearing laboratory rock analysis, we established the functions through which the porosity and permeability obtained though conventional method can be converted to the values of the subsurface conditions. With this method, the porosity and permeability of the Jurassic strata at the time of previous Tertiary and that in nowadays are reconstructed respectively, and then the characteristics of the distribution of high porosity-high permeability carrier beds in the evolution processes are determined. With the result of these works, it is found that both well Cai 43 region and Cainan oilfield are located on the preferential conduit direction of hydrocarbon migration. This conclusion is consistent with the result of the fluid potential analysis, in which fluid potential of nowadays and that of later Cretaceous are considered. At the same times, experiment of hydrocarbon injection into the addictive-pressure bearing rock is designed and conducted, from which it is found that, for mid-permeability cores of Jurassic, 0.03MPa is the threshold values for the hydrocarbon charging. And here, the conception of lateral pressure gradient is proposed to describe the lateral driving force for hydrocarbon migration. With this conception, it is found that hydrocarbons largely distributed in the areas where lateral pressure gradient is greater than 0. 03MPa/100m. Analysis of critical physical properties indicated that the value of the critical porosity and critical permeability varied with burial depth, and it is the throat radius of a certain reservoir bed that works as a key factor in controlling hydrocarbon content. Three parameters are proposed to describe the critical physical properties in this dissertation, which composite of effective oil-bearing porosity、effective oil-bearing permeability and preferential flow coefficient. And found that critical physical properties, at least to some extent, control the hydrocarbon distribution of Jurassic in Baijiahai uplift. Synthesize the content discussed above, this dissertation analyzed the key factors i.e., critical physical properties、driving force、conduit system and fluid potential, which controlled the formation of the lithologic reservoir in Baijiahai uplift. In all of which conduit system and fluid potential determined the direction of hydrocarbon migration, and substantially they are critical physical properties of reservoir bed and the lateral pressure gradient that controlled the eventually hydrocarbon distribution. At the same times, sand bodies in the major target formation that are recognized by reservoir bed simulation are appraised, then predict favorite direction of the next step exploration of lithologic reservoir.

冀东油田柳南地区新近系油藏剩余油形成及分布规律研究

This thesis is based on the research project of Study on the Geological Characteristics and Remaining Oil Distribution Law of Neogene Reservoirs in Liunan Area, which is one of the key research projects set by PetroChina Jidong Oilfield Company in 2006. The determination of remaining oil distribution and its saturation changes are the most important research contents for the development and production modification of oilfields in high water-cut phases. Liunan oilfield, located in Tangshan of Hebei Province geographically and in Gaoliu structural belt of Nanpu sag in Bohai Bay Basin structurally, is one of the earliest fields put into production of Jidong oilfield. Focusing on the development problems encountered during the production of the field, this thesis establishes the fine geological reservoir model through the study of reservoir properties such as fine beds correlation, sedimentary facies, micro structures, micro reservoir architecture, flow units and fluid properties. Using routine method of reservoir engineering and technology of reservoir numerical modeling, remaining oil distribution in the target beds of Liunan area is predicted successfully, while the controling factors of remaining oil distribution are illustrated, and the model of remaining oil distribution for fault-block structure reservoirs is established. Using staged-subdivision reservoir correlation and FZI study, the Strata in Liunan Area is subdivided step by step; oil sand body data-list is recompiled; diagram databases are established; plane and section configuration of monolayer sandstone body, and combination pattern of sandstone bodys are summarized. The study of multi-level staged subdivision for sedimentary micro-facies shows that the Lower member of Minghuazhen formation and the whole Guantao formation in Liunan Area belong to meandering river and braided river sedimentary facies respectively, including 8 micro facies such as after point bar, channel bar, channel, natural levee, crevasse splay, abandoned channel, flood plain and flood basin. Fine 3D geological modeling is performed through the application of advanced software and integration of geological, seismic logging and reservoir engineering data. High resolution numerical simulation is performed with a reserve fitting error less than 3%, an average pressure fitting fluctuation range lower than 2Mpa and an accumulate water cut fitting error less than 5%. In this way, the distribution law of the target reservoir in the study area is basically recognized. Eight major remaining oil distribution models are established after analysis of production status and production features in different blocks and different layers. In addition, fuzzy mathematics method is used to the integreted evaluation and prediction of abundant remaining oil accumulation area in major production beds and key sedimentary time units of the shallow strata in Liunan Area and corresponding modification comments are put forward. In summary, the establishment of fine reservoir geological model, reservoir numerical simulation and distribution prediction of remaining oil make a sound foundation for further stimulation of oilfield development performance.

孤岛油田中二北区Ng3～6储层建筑结构与油水分布规律研究

The reservoir of Zhongerbei region in Gudao Oilfield is a typical fluvial facies deposit, its serious heterogeneity of the reservoir caused the distribution of remaining oil in mature reservoirs is characterized by highly scattered in the whole field, and result to declination of production, tap potential and stabilize production is more difficult. Reservoir modeling based on lay scale can not fulfill requirement. How to further studied reservoir heterogeneity within the unit and establish the finer reservoir modeling is a valid approach to oil developing. The architectural structure elements analysis is the effectively method to study reservoir heterogeneity. Utilize this method, divide the reservoirs of Gudao Oilfield into ten hierarchies. The priority studying is sixth, seven hierarchies, ie single sand layers sand bodies By the identification of sixth, seven hierarchies, subdivide the reservoir to the single genetic unit. And to subdivide by many correlation means, such as isometry and phase transition, accomplish closure and correlation of 453 wells.Connectting fluvial deposit pattern, deposition characteristic with its log, build the inverting relation between “sedimentary facies” and “electrofacies” The process emphasize genetic communication and collocation structure of genetic body in space. By detailed architecture analyses sandbodies’ structure, this paper recognize seven structure elements, such as major channel, abandoned channel, natural levee, valley flat, crevasse splay, crevasse channel and floodplain fine grain.Combination identification of architectural structure elements with facieology and study of deposition characteristic, can further knowing genesis and development of abandoned channel. It boost the accuracy to separation in blanket channel bodies distribution, and provide reference to retrieving single channel boundary. Finally, establish fine plane and section construction. On basis architectural structure map, barrier beds and interbeds isopach map and mini-structure map, considering single thin layers to be construction unit, the main layer planimetric maps have drawn and the inner oil-water boundary have revealed. All account that architectural structure elements control remaining oil distribution in layer, and develop the study on architectural structure elements to direct horizontal well is succesful.

鄂尔多斯盆地子洲气田二叠系山西组储层特征与天然气富集规律研究

In this thesis, detailed studies on the sedimentology and petrophysical properties of reservoir rocks in the Shan#2 Member of Shanxi Formation, Zizhou gas field of Ordos Basin, are carried out, based on outcrop description, core description, wireline log interpretation and analysis of petrophysical properties. In the context of stratigraphic division scheme of the Upper Paleozoic in Ordos Basin, the Shan#2 Member is further divided into three subintervals: the Shan#23, Shan#22 and Shan#21, based on the marker beds���depositional cycles, wireline log patterns. Subaqueous deltaic-front distributary channels, distributed from the south to north, is identified，which is the main reservoir sand bodies for gases of Shan#2 Member at Zizhou gas field. Quartzose and lithic-quartzose sandstones, commonly with a high volume of cement, but a low volume of matrix, are the major reservoir rocks in the studied area. All sandstones have been evolved into the late diagenetic stage (referred to as diagenetic stage B) during the burial, experiencing compaction, cementation, replacement and dissolution, in which the compaction and cementation could have reduced the porosity, while dissolution could have improved the petrophysical properties. The pore types in the reservoirs are dominated by intergranular-solutional, intergranular-intercrystal and intercrystal-solutional porosity. According to the parameters and capillary pressure curves of test samples, five types of pore texture (I-V) are differentiated, in which types II and III pore textures displayed by low threshold pressure-wide pore throat and moderate threshold pressure-moderately wide pore throat, exist widespread. Sandstone reservoirs in the studied area are characterized by exceptionally low porosity and permeability, in which the petrophysical properties of those in Shan#23 horizon are relatively better. The petrophysical property of reservoirs was influenced both by the sedimentation and diagenesis. In general, the coarse quartzose sandstones deposited in subaqueous distributary channels show the best petrophysical property, which tends to be worse as the grain size decreases and lithic amount increases. Three types of gas reservoirs in Shan#23 horizon are classified according to petrophysical properties (porosity and permeability), which could have been influenced by the initial depositional facies, diagenesis and tectonics. On the basis of the study on the geological conditions of reservoirs in the area, it is concluded that sedimetary facies, diagenesis and tectonic actions can provide an important foundation for gas pool formation, which can also control the accumulation and distribution of gas reservoirs.

甘肃临夏盆地龙担剖面晚新生代磁性地层与古环境

Linxia Basin, situated in the northeast belt of the Tibetan Plateau, is a late Cenozoic depression basin bounded by the Tibetan Plateau and the Chinese Loess Plateau. The Cenozoic deposition, spanning over 30Ma, in which very abundant mammal fossils were discovered, is very suitable for study of uplift processes and geo-morphological evolution of the Tibetan Plateau. The Longdan section (35°31′31.6″N，103°29′0.6″E) is famous for the middle Miocene Platybelodon fauna and the late Miocene Hipparion fauna for a long time and is also one of the earliest known places for wooly rhino, which lies on the east slope of Longdan, a small village of township Nalesi in the south of the Dongxiang Autonomous County, Linxia Hui Nationallity Autonomous Prefecture. The Longdan mammal fauna was discovered at the base of the Early Pleistocene loess deposits at Dongxiang, where the lithology is different from the typical Wucheng Loess on the Chinese Loess Plateau. The rich fossils contain many new species and the major two layers of fossils are in the loess beds. Geologically the fossiliferous area is located in the central part of the Linxia Cenozoic sedimentary basin. Tectonically the Linxia Basin is an intermountain fault basin, bordered by the Leijishan major fault in the south and the north Qinling and Qilianshan major faults in the north. The section is 51.6m thick above the gravel layer, including the 1.6m Late Pleistocene Malan Loess on the top and the other loess-paleosol sequences in the middle of the section. The base of the section is the Jishi Formation, consisting of gravel layer of 13 ~ 17m thick. In this study, 972 bulk samples were collected with an interval of 5cm and other 401 orientied samples were taken with a magnetic compass. In the laboratory, the paleomagnetism, medium grain size, susceptibility, color, micromorphology, anisotropy of magnetic susceptibility were analyzed. From the stratigraphic analysis, the Longdan section from the top 0.3m to the bottom 51.6m, containing 5 normal polarities (N1-N5) and 5 reversal polarities (R1-R5). The paleomagnetic results show N3 is the Olduvai subchron in the middle of the Matuyama chron, and then the chronology of the Longdan mammal fauna is constructed along the section. The Matuyama-Gauss boundary is 45m and N5 enters Gauss chron. The Olduvai subchron with the age of 1.77 ~ 1.95Ma is found just in the upper fossiliferous level of Longdan mammal fauna. Taking the deposit rate of the section into account, the geological age of the upper fossiliferous level of Longdan mammal fauna is estimated to be about 1.9Ma. The lower fossiliferous level is just below the Reunion subchron and its age is estimated to be 2.25Ma. In addition, anisotropy of magnetic susceptibility of the loess-paleosol and other climatic indexes were used for discussing the late Cenozoic paleoenvironmental changes at Longdan, from which the Longdan area should have been an area of predominantly steppe the same as the Longdan mammal fauna.

松辽盆地南部大情字井地区CO2埋存体地质格架及储层建模

Increasing attentions have been paid to the subsurface geological storage for CO2 in view of the huge storage capacity of subsurface reservoirs. The basic requirement for subsurface CO2 storage is that the CO2 should be sequestrated as supercritical fluids (physical trapping), which may also interact with ambient reservoir rocks and formation waters, forming new minerals (chemical trapping). In order to the effective, durable and safe storage for CO2, enough storage space and stable sealing caprock with strong sealing capacity are necessitated, in an appropriate geological framework. Up till now, hydrocarbon reservoirs are to the most valid and appropriate CO2 storage container, which is well proven as the favorable compartment with huge storage capacity and sealing condition. The thesis focuses on two principal issues related to the storage and sealing capacity of storage compartment for the Qingshankou and Yaojia formations in the Daqingzijing block, Southern Songliao Basin, which was selected as the pilot well site for CO2-EOR storage. In the operation area, three facies, including deltaic plain, deltaic front and subdeep-deep lake facies associations, are recognized, in which 11 subfacies such as subaqueous distributary channel, river- mouth bar, interdistributary bay, sheet sandbody, crevasse splay and overflooding plain are further identified. These subfacies are the basic genetic units in the reservoir and sealing rocks. These facies further comprise the retrogradational and progradational depositional cycles, which were formed base- level rise and fall, respectively. During the regressive or lake lowstand stage, various sands including some turbidites and fans occurred mostly at the bottom of the hinged slope. During the progradation stage, these sands became smaller in size and episodically stepped backwards upon the slope, with greatly expanded and deeped lake. However, most of Cretaceous strata in the study area, localized in the basin centre under this stage, are mainly composed of grey or grizzly siltstones and grey or dark grey mudstones intercalated with minor fine sandstones and purple mudstones. On the base of borehole and core data, these siltstones are widespread, thin from 10 to 50 m thick, good grain sorting, and have relative mature sedimentary structures with graded bedding and cross- lamination or crossbeds such as ripples, which reflect strong hydrodynamic causes. Due to late diagenesis, pores are not widespread in the reservoirs, especially the first member of Qingshankou formation. There are two types of pores: primary pore and secondary cores. The primary pores include intergranular pores and micropores, and the secondary pores include emposieus and fracture pores. Throat channels related to pores is also small and the radius of throat in the first, second and third member of Qingshankou formation is only 0.757 μm, 0.802 μm and 0.631 μm respectively. In addition, based on analyzing the probability plot according to frequency of occurrence of porosity and permeability, they appear single- peaked distribution, which reflects strong hetero- geneity. All these facts indicate that the conditions of physical property of reservoirs are not better. One reason may be provided to interpret this question is that physical property of reservoirs in the study area is strong controlled by the depositional microfacies. From the statistics, the average porosity and permeability of microfacies such as subaqueous distributary channel, channel mouth bar, turbidites, is more than 9 percent and 1md respectively. On the contrary, the average porosity and permeability of microfacies including sand sheet, flagstone and crevasse splay are less than 9 percent and 0.2md respectively. Basically, different hydrodynamic environment under different microfacies can decide different physical property. According to the reservoir models of the first member of Qingshankou formation in the No. well Hei47 block, the character of sedimentary according to the facies models is accord to regional disposition evolution. Meantime, the parameter models of physical property of reservoir indicate that low porosity and low permeability reservoirs widespread widely in the study area, but the sand reservoirs located in the channels are better than other places and they are the main sand reservoirs. The distribution and sealing ability of fault- fractures and caprock are the key aspects to evaluate the stable conditions of compartments to store CO2 in the study area. Based on the core observation, the fractures widespread in the study area, especially around the wells, and most of them are located in the first and second member of Qingshankou formation, almost very few in the third member of Qingshankou formation and Yaojia formation instead. In addition, analyzing the sealing ability of eleven faults in the three-dimensional area in the study area demonstrates that most of faults have strong sealing ability, especially in the No. well Hei56 and Qing90-27. To some extent, the sealing ability of faults in the No. well Hei49, Qing4-6 and Qing84-29 are worse than others. Besides, the deposition environment of most of formations in the study area belongs to moderately deep and deep lake facies, which undoubtedly take advantage to caprocks composed of mudstones widespread and large scale under this deposition environment. In the study area, these mudstones distribute widely in the third member of Qingshankou formation, Yaojia and Nenjiang formation. The effective thickness of mudstone is nearly ~550m on an average with few or simple faults and fractures. In addition, there are many reservoir beds with widely- developed insulated interbeds consist of mudstones or silty mudstone, which can be the valid barrier to CO2 upper movement or leakage through diffusion, dispersion and convection. Above all, the closed thick mud caprock with underdeveloped fractures and reservoir beds can be taken regard as the favorable caprocks to provide stable conditions to avoid CO2 leakage.

宣龙式赤铁矿含矿岩系的成矿过程研究

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.

南海北部大陆边缘盆地热演化史及其与油气关系

This thesis focuses on the present-day thermal field features, evolution and their connections to hydrocarbon generation of the three continental margin basins-the Yinggehai (Yingge Sea), Qiongdongnan(southeast Qiong), and Pear River Mouth basins-in northern South China Sea, based on available data from drillings, loggings, seismic cross-sections, BHTs, thermal indicators (Ro%, inclusion, etc) and geopressure measurements. After studying of present-day distribution of geothermal field and thermal disturbance of fluid in the sedimentary strata, the author discovered that the distribution of gas fields in Yinggehai Basin are closely related to the distribution of anomalously high thermal gradient area, whereas it is not the case for the Pear River Mouse Basin. And detailed processing of the fluid inclusion data indicates that geothermal fluids activated frequently in this area, and they may mainly be derived upward from the overpressure and hydrocarbon-generating beds, 3000-4500 m in depth. Therefore, the abnormal gradients in sedimentary beds were mainly caused by the active geothermal fluids related to hydrocarbon migrating and accumulating in this area. Because of the effect of overpressure retarding on vitrinite reflectance, the thermal indicators for thermal history reconstruction should be assessed before put into use. Although some factors, such as different types of kerogen, heating ratio, activities of thermal fluids and overpressure, may have effects on the vitrinite reflectance, under the circumstance that thermal fluids and overpressure co-exist, overpressure retarding is dominant. And the depth and correction method of overpressure retarding were also determined in this paper. On the basis of reviewing the methods of thermal history studies as well as existing problems, the author believes that the combination of thermal-indicator-inversion and tectono-thermal modeling is an effective method of the thermal history reconstruction for sedimentary basins. Also, a software BaTherMod for modeling thermal history of basins was successfully developed in this work. The Yinggehai Basin has been active since Tertiary, and this was obviously due to its tectonic position-the plate transition zone. Under the background of high thermal flow, long-term quick subsidence and fluid activities were the main reasons that lead to high temperature and overpressure in this basin. The Zhujiangkou Basin, a Tertiary fault-basin within the circum-Pacific tectonic realm, was tectonically controlled by the motion of the Pacific Plate and resembles the other petroliferous basins in eastern China. This basin developed early, and characterized intensive extension in the early stage and weak activity in the later stage of its development. Whereas the Qiongdongnan Basin was in a weak extension early and intensity of extension increased gradually. The relative geographical locations and the extensional histories of three basins ilustrate that the northern continental margin of South China Sea spread from south to north. On the other hand, the Qiongdongnan and Yinggehai Basins may have been controlled by the same tectonic regime since later Tertiary, whereas the Zhujiangkou Basin was not meaningfully influenced. So, the tectono-thermal evolution character of the Qiongdonnan basin should be closely to the other two. It may be concluded that the three basins have been developed within the active continental margin since Tertiary, and the local lithosphere might undergo intensive extension-perhaps two or three times of episodic extension occurred. Extension lead to large tectonoc subsidence and extreme thick Tertiary sediments for hydrocarbon generation in the basins. In response to the periodic extension of the basins, the palaeothermal flow were also periodical. The three basins all have the characteristics of multi-phase thermal evolutions that is good for oil-gas generation. And the overpressure expands the depth range of oil-gas habitat, which is meaningful to petroleum exploration in this region.

准噶尔盆地三个泉凸起油气成藏条件及动力学研究

Sangequan Uplift in Junggar Basin is an inherited positive structure, which has undergone many times of violent tectonic movements, with high tectonic setting, and far away from the oil-source sag, reservoir forming condition is complex. Combining sequence stratigraphy, depositional facies, reservoir formation theory with seismic and well logging analysis, this paper conducted integrated study on the hydrocarbon migration, accumulation, entrapment conditions, the reservoir forming dynamics and the forming model, and acquired the following recognition: (1) The special reservoir formation conditions that enable Sangequan Uplift to form a giant oil-gas field of over 100 million tons of reserves are as follows: (D Deltaic frontal sandbody is developed in Jurassic Xishanyao Formation, Toutunhe Formation and Lower Cretaceous Hutubihe Formation, with good reservoir quality;? Abundant hydrocarbon resources are found in Western Well Pen-1 Sag, which provides sufficient oil sources for reservoir formation of Sagequan Uplift; ?The unconformity-fault-sandbody system has formed a favorable space transporting system and an open conduit for long-distance hydrocarbon migration; ?fault, low amplitude anticline and lithological traps were well developed, providing a favorable space for hydrocarbon accumulation. (2) The most significant source beds in the Western Well Pen-1 Sag are the Mid-Permian Lower Wuerhe Formation and Lower-Permian Fengcheng Formation. The oil in the Well Block Lu-9 and Shinan Oilfield all originated from the hydrocarbon source beds of Fengcheng Formation and Lower Wuerhe Formation in the Western Well Pen-1 Sag and migrated through Jidong and Jinan deep faults linking unconformity of different regions from sources to structural highs of the uplift and shallow horizons. (3) There were 2 reservoir formation periods in District Sangequan: the first was in late Cretaceous during which the upper part of Xishanyao Formation and Toutunhe Formation; the second was in Triassic, the main resources are high-maturity oil and gas from Fengcheng Formation and Wuerhe Formation in Western Pen-1 Well sag and the gas from coal measure strata of Xishanyao Formation, that were accumulated in Hutubihehe Formation. (4) Model of the hydrocarbon migration, accumulation, reservoir formation of the study area are categorized as three types starting from the hydrocarbon source areas, focusing on the faults and unconformity and aiming at reservoirs: ① Model of accumulation and formation of reservoir through faults or unconformities along the "beam" outside source; ②Model of migration, accumulation and reservoir formation through on-slope near source;③Model of migration, accumulation and reservoir formation of marginal mid-shallow burial biogas-intermediate gas. (5) Pinchout, overlap and lithologic traps are developed in transitional zones between Western Well Pen-1 sag and Luliang uplift. Many faulted blocks and faulted nose-like traps are associated with large structures on Sangequan uplift. Above traps will be new prospecting areas for further hydrocarbon exploration in future.

东营凹陷中央隆起带次生油藏成藏机制和预测

It is the key project of SINOPEC at ninth five years period with a lot of work and very difficult, which the main object are the study of pool-forming mechanism, distribution rule and pool-forming model of complex secondary pool at Dongying formation in high mature exploration area, and building theories and methods of research, description and prediction of secondary fault block pool. This paper apply comprehensively with various theories, method and techniques of geology, seismic, well log, reservoir engineering, meanwhile apply with computer means, then adopt combination of quality and quantitative to develop studies of pool-forming mechanism, model and pool prediction of fault block pool. On the based of stretch, strike-slip, reversal structure theories, integrated the geometry, kinematics, and dynamics of structure, it is show that the structure framework, the structure evolve, formation mechanism of central uplift belt of Dongying depression and control to formation and distribute of secondary complex fault block pool. The opening and sealing properties, sealing mechanism and sealing models of pool-controlling fault are shown by using quality, direction of normal stress, relations between interface and rock of two sides of fault and shale smear factor (SSF), as well as the juxtaposition of fault motion stage and hydrocarbon migration, etc. The sealing history of controlling fault, formation mechanism and distribute the regulation are established by combining together with bury history, structure evolve history, fault growth history stress field evolve history, which can be guide exploration and production oil field. It were bring up for the first time the dynamics mechanism of Dongying central uplift which were the result of compound tress field of stretch, strike-slip and reversal, companion with reversal drag structure, arcogenesis of paste and salt beds. The dual function of migration and sealing of fault were demonstrated in the research area. The ability of migration and sealing oil of pool-controlling fault is controlled by those factors of style of fault combination, activity regulation and intensity of fault at the period of oil migration. The four kinds of sealing model of pool-controlling fault were established in the research area, which the sealing mechanism of fault and distribution regulation of oil in time and space. The sealing ability of fault were controlled by quality, direction of normal stress, relations between interface and rock of two sides of fault and shale smear factor (SSF), as well as the juxtaposition of fault motion stage and hydrocarbon migration, etc. The fuzzy judge of fault sealing is the base of prediction of secondary pool. The pool-forming model of secondary was established in the research area, which the main factors are ability migration and sealing. The transform zone of fault, inner of arc fault and the compound area of multi fault are enrichment region of secondary pool of Dongying formation, which are confirm by exploration with economic performance and social performance.

西南天山托云盆地白垩-新生代古地磁结果及其构造意义

Western China is regarded as an assemblage of blocks or microplates. The India/Asia postcollisional kinematics of these blocks has attracted many geologists to pay attentions, especially on the geodynamics and intracontinental deformation of Tibetan and adjoining parts of central Asia. So far there are still many debates on the amount of continental shortening and extrusion within Western China blocks. Paleomagnetism plays a very important role in the paleogeographic reconstruction and depiction of kinematics of the blocks, however the unequilibrium of paleomagentic data obtained from Western China prevents paleomagnetists from studying the kinematics and intracontinental deformation on the Tibetan plateau and the central Asia. Moreover, shallower inclinations observed in the Cretaceous and Cenozoic terrestrial red sediments in central Asia makes it difficult to precisely estimate the northward convergence of Tibetan plateau and its adjacent areas since the onset of the Indian/Asian collision. In this thesis, detailed rock magnetic, chronological and paleomagnetic studies have been carried out on the Tuoyun Basin in the southwestern Tianshan to discuss the possible continental shortening and tectonic movements since the Cretaceous-Tertiary. Ar-Ar geochronological study has been conducted on the upper and lower basalt series from the Tuoyun Basin, yielding that the lower and upper basalt series were extruded during 115-113 Ma and 61.8-56.9 Ma, respectively. Both the age spectrum and inverse isochron show that the samples from the upper and lower basalt series have experienced no significant thermal events since extrusion of the baslts. Rock magnetic studies including temperature dependence of magnetization and susceptibility during a heating-cooling cycle from temperature up to 600 ℃ suggest that the baslt samples from the lower and upper basalt series are ferromagnetically predominant of magnetite and a subordinate hematite with a few sites of titanomagnetite. The predominant magnetic mineral of the intercalated red beds is magnetite and hematite. Anisotropy of magnetic susceptibility shows that both the baslts and the intercalated red beds are unlikely to have undergone significant strain due to compaction or tectonic stress since formation of the rocks. The stable characteristic remanent magnetization (ChRM) isolated from the most samples of the upper and lower basalt series and intercalated red beds, passes fold test at the 99% confidence level. Together with the geochronological results, we interpret the characteristic component as a primary magnetization acquired in the formation of rocks. Some sites from both the upper and lower basalts yielded shallower inclinations than the reference field computed from the Eurasia APW, we prefer to argue that these shallow inclinations might be related to geomagnetic secular variation, whereas the shallow inclination in the intercalated red beds is likely to be related to detrital remanent magnetization. Paleomagnetic results from the early Cretaceous-Paleogene basalts indicate that no significant N-S convergence has taken place between the Tuoyun Basin and the south margin of Siberia. Furthermore, the Cretaceous and Tertiary paleomagnetic results suggest that the Tuoyun Basin was subjected to a local clockwise rotation of 20°-30° with respect to Eurasia since the Paleocene time, which is probably subsequent to the Cenozoic northward compression of the Pamir arc.

陆相砂泥岩层序的高精度检测方法研究及应用

Ordos Basin is a typical cratonic petroliferous basin with 40 oil-gas bearing bed sets. It is featured as stable multicycle sedimentation, gentle formation, and less structures. The reservoir beds in Upper Paleozoic and Mesozoicare are mainly low density, low permeability, strong lateral change, and strong vertical heterogeneous. The well-known Loess Plateau in the southern area and Maowusu Desert, Kubuqi Desert and Ordos Grasslands in the northern area cover the basin, so seismic data acquisition in this area is very difficult and the data often takes on inadequate precision, strong interference, low signal-noise ratio, and low resolution. Because of the complicated condition of the surface and the underground, it is very difficult to distinguish the thin beds and study the land facies high-resolution lithologic sequence stratigraphy according to routine seismic profile. Therefore, a method, which have clearly physical significance, based on advanced mathematical physics theory and algorithmic and can improve the precision of the detection on the thin sand-peat interbed configurations of land facies, is in demand to put forward.Generalized S Transform (GST) processing method provides a new method of phase space analysis for seismic data. Compared with wavelet transform, both of them have very good localization characteristics; however, directly related to the Fourier spectra, GST has clearer physical significance, moreover, GST adopts a technology to best approach seismic wavelets and transforms the seismic data into time-scale domain, and breaks through the limit of the fixed wavelet in S transform, so GST has extensive adaptability. Based on tracing the development of the ideas and theories from wavelet transform, S transform to GST, we studied how to improve the precision of the detection on the thin stratum by GST.Noise has strong influence on sequence detecting in GST, especially in the low signal-noise ratio data. We studied the distribution rule of colored noise in GST domain, and proposed a technology to distinguish the signal and noise in GST domain. We discussed two types of noises: white noise and red noise, in which noise satisfy statistical autoregression model. For these two model, the noise-signal detection technology based on GST all get good result. It proved that the GST domain noise-signal detection technology could be used to real seismic data, and could effectively avoid noise influence on seismic sequence detecting.On the seismic profile after GST processing, high amplitude energy intensive zone, schollen, strip and lentoid dead zone and disarray zone maybe represent specifically geologic meanings according to given geologic background. Using seismic sequence detection profile and combining other seismic interpretation technologies, we can elaborate depict the shape of palaeo-geomorphology, effectively estimate sand stretch, distinguish sedimentary facies, determine target area, and directly guide oil-gas exploration.In the lateral reservoir prediction in XF oilfield of Ordos Basin, it played very important role in the estimation of sand stretch that the study of palaeo-geomorphology of Triassic System and the partition of inner sequence of the stratum group. According to the high-resolution seismic profile after GST processing, we pointed out that the C8 Member of Yanchang Formation in DZ area and C8 Member in BM area are the same deposit. It provided the foundation for getting 430 million tons predicting reserves and unite building 3 million tons off-take potential.In tackling key problem study for SLG gas-field, according to the high-resolution seismic sequence profile, we determined that the deposit direction of H8 member is approximately N-S or NNE-SS W. Using the seismic sequence profile, combining with layer-level profile, we can interpret the shape of entrenched stream. The sunken lenticle indicates the high-energy stream channel, which has stronger hydropower. By this way we drew out three high-energy stream channels' outline, and determined the target areas for exploitation. Finding high-energy braided river by high-resolution sequence processing is the key technology in SLG area.In ZZ area, we studied the distribution of the main reservoir bed-S23, which is shallow delta thin sand bed, by GST processing. From the seismic sequence profile, we discovered that the schollen thick sand beds are only local distributed, and most of them are distributary channel sand and distributary bar deposit. Then we determined that the S23 sand deposit direction is NW-SE in west, N-S in central and NE-SW in east. The high detecting seismic sequence interpretation profiles have been tested by 14 wells, 2 wells mismatch and the coincidence rate is 85.7%. Based on the profiles we suggested 3 predicted wells, one well (Yu54) completed and the other two is still drilling. The completed on Is coincident with the forecastThe paper testified that GST is a effective technology to get high- resolution seismic sequence profile, compartmentalize deposit microfacies, confirm strike direction of sandstone and make sure of the distribution range of oil-gas bearing sandstone, and is the gordian technique for the exploration of lithologic gas-oil pool in complicated areas.