用波动方程建立蠕动爬行攻泥机器人海底土力学运动模型

针对目前国内海底蠕动爬行机器人攻打千斤洞的特点 ,在对海洋沉积土的工程性质进行分析的基础上 ,利用流变力学的理论 ,提出用波动方程来建立攻泥机器人周期性冲击土壤的力学模型 ,用后向差分法解波动方程 ,得到土壤的位移和变形公式 ,确定土壤对攻泥机的阻力 .通过对模型的仿真 ,证明了用该模型计算阻力的可行性 .

砂泥岩储层测井产能预测方法研究

Productivity prediction is very important in the exploration and development of oilfields. Using well log data to predict productivity is a front-line technology， which is key issue in petroleum exploration phase. The essential factors of productivity prediction is building practical models and correcting various causes to improve precision of prediction parameters. Any errors of parameters selections can affect the calculation of productivity prediction; therefore， how to improve research means and calculation accuracy is an important task of productivity prediction. Theory and case examples are deeply and comprehensively studied in the paper. Based on the theory of mud-filtrate invasion and experimental results， the damage of drilling， cementing， perforating，acidizing and fracturing were investigated. The damage depth was quantitatively evaluated by log data， based on this， the processing results of reservoir sensitivity were used to analysis quantitatively the damage of reservoir. The productivity prediction and reservoir damage were initiatively incorporated according to well logging， and the precision of productivity prediction was effectively improved. The method of NMR was explored to calculate the fluid viscosity on the basis of reservoir physical method， and the differences between the two methods were compared in the paper. From the theory fluid flow in porous media， various of theoretical models of production prediction were explored and several practical models were consided， such as productivity index method， improved productivity index method， improved Bearder method， SVM and so on. The characteristic and the application scope of these methods were studied. The inflow productivity and outflow productivity were incorporated and nodal analysis method was used to forecast wellhead yield， thus achieved scientifically production. On the applied background of conventional logging suite， the applying of special items or new logging method which is practical in the research area were studied， the logging suite was further optimized， and the precision of forecast was improved. On the basis of the modeling and the calculation of parameters， these methods were verified and analyzed， and the reconstruct principle was also built for block reservoir. The research block was processed by these methods and compared with testing data. Based on above the research， a technological system which is practical for shaly sand profiles in Shengli Oilfield was built. The system can reach commercialized degree，and satisfied the need of exploration and development of the oilfield.

黄骅坳陷马东地区沙河街组重力流水道储层评价及剩余油研究

In this paper, taking Madong district of Huanghua depression as a case, based on the theory of sequence stratigraphy, sedimentology, reservoir geology and geophysics, according to core analysis, seismic attribute analysis, logging constrained inversion, multi-data correlation of strata, reservoir modeling, etc. the lower and middle first member of Shahejie formation of the study area was forecasted and evaluated. As a result, a number of reservoir prediction and remaining oil distribution methods suitable to oil exploitation of gravity flow channel reservoir are presented. Scientific foundation is provided to the next adjustment of development program and exploitation of the remaining oil. According to high resolution sequence stratigraphy theory, precise stratigraphic framework was founded, the facies types and facies distribution were studied under the control of stratigraphic framework, the technologies of seismic attribute abstraction and logging constrained inversion. Result shows that gravity flow channel, as the main facies, developed in the rising period of base-level cycle, and it was formed during the phase of contemporaneous fault growth. As the channel extends, channel width was gradually widened but thickness thined. The single channels were in possession of a great variety of integrated modes, such as isolated, branching off, merging and paralleling, forming a kind of sand-mud interblending complex sedimentary units. Reservoir quality differs greatly in vertical and horizontal direction, and sedimentary microfacies is main controlling factor of the reservoir quality. In major channel, deposition thickness is great, and petrophysical property is well. While in marginal channel, reservoir is thinner, and petrophysical property is unfavorable. Structure and reservoir quality are main factors which control the oil and gas distribution in the study area. On the basis of the research about the reservoir quality, internal, planar and 3-D reservoir heterogeneities are characterized, and the reservoir quality was sorted rationally. At last, based on the research of reservoir numerical simulation of key well group, combined with reservoir performance analysis and geological analysis above, remaining oil distribution patterns controlled by internal rhythm of gravity flow channel were set up. Through this research, a facies-restrained reservoir prediction method integrating multi-information was presented, and potential orientation of remaining oil distribution in gravity flow channel reservoir is clarified.

基于弹性参数分析的碳酸盐岩储层预测方法研究

Prediction of Carbonate Reservoir Based on the Elastic Parameter Analysis Zhang Guangzhi (Solid Geophysics) Directed by Professor Liu Hong Abstract With the exploration and development of Puguang Oilfield, oil-gas exploration of carbonate rock in China has shown good prospects. Research on earthquake prediction methods for carbonate reservoir becomes the key of oil and gas exploration. Starting with analysis of geological characteristics of carbonate rock, prestack AVO inversion method, prestack elastic impedance inversion and parameter calculation method and seismic attribute extraction and optimization method were studied based on the analysis of rock physics in this work. First, variation characteristic and law of carbonate rock reservoir parameters were studied based on experimental data of rock physics, log data, analysis assay data, mud logging data and seismic data, so as to lay a foundation for the further reservoir identification and description. Then, the structure, type and propagation law of seismic wave field were analyzed through seismic forward modeling of the reservoir, and contact between information from log and geology data with elastic parameters, such as compressional wave and shear wave velocity and density were established, so as to provide a standard for reservoir identification and hydrocarbon detection using seismic reflection characteristics of the research area. Starting with the general concept of inverse problem, through analysis of Zoeppritz equation, three kinds of pre-stack inversion methods were derived and analyzed in detail, the AVO 3-parameter inversion based on Bayesian theory, the prestack AVO waveform inversion method and the simultaneous inversion method, based on the statistical hypothesis of inversion parameters and observation data and the Gauss distribution assumption of noise. The three methods were validated by model data and real data. Then, the elastic wave impedance inversion method of carbonate reservoir was investigated and the method of elastic parameter extraction from elastic impedance data was put forward. Based on the analysis of conventional methods of seismic attribute extraction and optimization, the time-frequency attributes and the wavelet attributes with time and amplitude feature were presented, and the prestack seismic attribute calculation method which can characterize the reservoir rock and fluid characteristic was presented. And the optimization of seismic attribute using the nonlinear KPCA method was also put forward. A series of seismic prediction technologies for carbonate reservoir were presented based on analysis of rock physics and seismic forward simulation technology. Practical application of these technologies was implemented in A oil field of Southern China and good effect has been achieved. Key words: carbonate rock; reservoir prediction; rock physics, prestack seismic inversion; seismic attribute

元谋盆地河湖相沉积记录的上新世印度季风转型事件

The Indian monsoon, an integral part of the global climate system, has been extensively investigated during the past decades. Most of the proxy records are derived from marine sediments and focused on time periods of the late Miocene and Pleistocene. The Pliocene represents a period when Earth’s boundary conditions underwent dramatic changes. However, variations of the Indian monsoon during the Pliocene and its forcing mechanisms have remained unclear. The Yuanmou Basin, located in the region of the Indian monsoon, provides an ideal target for understanding the Pliocene history of Indian monsoon variations. Detailed investigations on the lithostratigraphy, magnetostratigraphy and limnology of a 650-m-thick fluvio-lacustrine sedimentary sequence from the basin are carried out in the present study. The clay and clay-plus-fine-silt fractions of the sediments are referred to the midlake-facies components, and changes in the percentages of both fractions generally reflect changes in the water level of the lakes developed in the basin closely related to variations in the intensity of the Indian monsoon. Whereas the greenish-gray lacustrine mud beds represent the environment of deep-water lakes, and the frequency of individual lacustrine mud beds is considered to indicate the frequency of the deep-water lakes developed in the basin associated with the variability of the Indian monsoon. The proxy data suggest that the Indian monsoon experienced abrupt shifts at 3.53, 3.14, 2.78 and 2.42 Ma, respectivey. 1) Since 3.53 Ma, the midlake-facies components displayed a general trend of increase in the concentrations, accompanied by an increase in the sedimentation rate from an average ~10 to 25 cm ka–1. The data suggest that high stands of the lakes in the basin rose progressively, implying a gradual intensification of the Indian monsoon since that time. This shift occurred coeval with the accelerated uplift of the northern Tibetan Plateau, denoting a close link between the Indian monsoon strengthening and the Tibetan Plateau uplifting. 2) 2.78 Ma ago, the concentrations of the midlake-facies components decreased abruptly and the dominant fraction of the sediments turned to fluvial sands. The data indicate that lakes in the basin disappeared, reflecting a dramatic decline in the intensity of the Indian monsoon at that time. This shift coincided with the formation of extensive Northern Hemisphere ice sheets, implying a quick response of the low-latitude monsoon regime to the high-latitude glaciation. 3) At 3.14 Ma, the initial appearance of blackish-grey mud beds with long durations and occasional occurrences of lacustrine mud beds indicate that the basin was overall dominated by shallow lakes, implying a shift to decreased variability of the Indian monsoon at that time. At 2.42 Ma, an increase in the frequency and a decrease in the duration of the lacustrine mud beds suggest that deep-water lakes were frequently developed in the basin, denoting a shift to increased variability of the Indian monsoon at that time. The former shift coincides with the onset of large-scale glaciation in the circum Atlantic region and the latter corresponds to the inception of predominance of the 41 ka periodicity in Northern Hemisphere ice-sheet cover fluctuations, presumably suggesting a physical link between the Indian monsoon system and the high-latitude ice sheets in the Northern Hemisphere.

鄂尔多斯盆地环县地区长6-长8沉积相及储层研究

The exploration in recent years shows that the Yanchang Formation in the southwest of Ordos Basin is of great resource potential and good exploration and exploitation prospect. In the thesis ，sedimentary source analysis，sedimentary system，sedimentary microfacies，sandstones distribution and reservoir characteristic are studied and favorable oil area are forecasted in Chang6-Chang8 of Yanchang formation in HuanXian region， by mainly study on the data of field section observation ，core observation, well logging explaination and routine microscope slice identification，scanning Electron Microscope and reservoir analysis of lithology and physical property , Under the guidance of such advanced theories and methods as sedimentology，reservoir sedimentology，lithological oil pool and so on. The stratum of Chang6-Chang8 of Yanchang formation could be divided into pieces of member following the principles that firstly contrasting the big segments, then contrasting the small segments, being controlled by cycle and consulting the thickness etc.And the characteristic of stratum are detailed discussed , respectively. Based on the source direction of the central basin, heavy and light minerals are used to analyse source direction of Chang6 and Chang8 member, in HuanXian area. Research result shows that the source of Chang6 and Chang8 member is mixed provenance,including west-south,west and east-north. By the study of rock types、 sedimentary conformation、lithology and electromotive curve combination and palaeo-biology,lake、delta and braided delta mianly developed in study area are recognized, Subaqueous distributary channels in delta front and in braided delta front, and sand body in deep-lake turbidite, are the main reservoir.forthermore,the characteristic of depositional system and sandy body in space are discussed. Applied with routine microscope slice identification, Scanning Electron Microscope, reservoir lithology and physical property analysis and other analytic machinery, Feldspar-lithic fine-sandstone and feldspar fine-sandstone are mainly sandstone of Y Chang6-Chang8 in Huanxian area, small pore and tiny pore are the main pore types, tiny throat type and micro-fine throat type are widely developed , secondary dissolution porosity, intercrystal porosity, tiny pore and micro-crack are main pore types.Intergranular porosity and dissolution porosity secondary is the main pore secondary. The dominant diagenesis types in the area are compaction, cementation, replacement and dissolution. Chlorite films cementation facies, carbonate cementation facies ,mud cementation compaction facie, compaction 、pressure solution facies are the main diagenetic facies,in which Chlorite films cementation facies is the best diagenetic facies in study area. Reservoir influence factor analysis ,rock types are the main factor forming this low-pore and low-permeability of Chang6-Chang8 member in study area,and relatively higher permeability area are cortrolled by sedimentary facies distribution, diagenesis improved reservoir physical property. According to the distributing of sedimentary micro-facies and sandy body , and the test oil, favorable region in Chang6-Chang8 are forecasted.

辽河盆地西部凹陷深部流体的地球化学特征与成藏效应

The main research area of this thesis is the Western Depression in the Liaohe Basin. Based on the drilling core observation and mud logging data, the features of the mantle–derived fluids and their effects on oil/gas generation in the Western Depression of the Liaohe Basin,was studied with comprehensive methods of volcanic petrology, sediment petrology, fluid geochemistry, sedimentlogy, and structural geology, and use of polarized light microscope, fluorescence microscope, electron microscope, fluid and melt inclusion test, and isotopic test of nature gas etc. The observation of drill cores in study area and other studies reveal that the main passageway of the volcanic eruption in the Cenozoic was the Xibaqian-Gaosheng fault, and the volcanic rocks of each stage were distributed around it. Mantle-derived fluid which affected on oil/gas generation formed later than the volcanic spew and those fluids entered into the depression through the Taian-Dawa fault and the Central fault. The volatile fraction analysis of the melt inclusion reveals the presence of two kinds of mantle fluids; they are hydrogen-rich fluid and carbon dioxide-rich fluid. These the two kinds of fluids were mainly distributed in olivine and pyroxene respectively. The hydrothermal veins development have multiple stages, from high temperature quartz vein to low temperature calcite vein and analcime vein, in which the fluid inclusion extremity component are methane and carbon dioxide, which indicate that when mantle-derived fluids ascended and entered into the basin, most of these fluids interacted with the organic matter in the basin even though some of these entered into atmosphere. The present isotopic test of the nature gas reveals the high 3He/4He value between the region of the Taian-Dawa fault and the Central fault, which also imply the feature of origin in mantle. This phenomenon indicates that the Mesozoic basement faults and the main Cenozoic faults had connected crust and the mantle during the basin evolution, so the mantle derived fluids could enter the basin along those faults. The main source rocks of the ES3 and ES4 members of the Shahejie Formation began to expel hydrocarbon at the end period of the ES1 member of the Shahejie Formation, and reached its peak during the period of the Dongying Formation deposition. During these periods, the mantle derived-fluids entered the basin constantly along the main faults, and supplied lots of hydrogen for hydrocarbon generation. Though the volcanic rocks and the mantle-derived fluids in the Eastern Depression were more developed than in the Western Depression, the source rocks and the deep fluids were not interacted better than the Western Depression because of the affection of structural evolution. In the Eocene, the Eastern Depression did not deposit the ES4 member of the Shahejie Formation, furthermore, the mantle-fluid formed in the Fangshengpao stage escaped to the atmosphere, which confined the later stage hydrocarbon generation capability.

AVO分析与地震资料叠前储层预测技术

In this paper we base on the anisotropic theory and Zoeppritz function of the transmission theory and the law of amplitude versus offset simplify seismic reflection coefficient of different media, analyze the characteristic of the gas or oil saturated stratum or the VTI and HTI models. Discuss the P wave reflection relationship and the meanings of the different parameters. We use measured parameters of a reservoir to simulate the characteristic of the reservoir, study the different effects of stratum saturated with gas or oil and analyze the characteristic of the seismic response of different models which change with different incident angles and different azimuths. Using the field data of logs ,analyze the rock property parameters, build the relationship of logs and parameters by Gassmann theory or empirical function. Calculate the density and the shear modulus and bulk modulus, reconstruct the log curves, calculate shear wave logs and correlate the logs affected by mud and other environmental factors. Finally perform the relationship of the seismic data log of saturated stratum and enhance the ability and reliability in reservoir prediction. Our aim is by the prestack seismic processing to get high solution and amplitude preserved seismic data. Because in incident angle gathers or azimuthal gathers, the low signal to noise ratio and low different covers affect the result of the prestack reservoir prediction. We apply prestack noise erase, cell regularization process and relatively amplitude preservation in the high solution seismic process routine to preserve the characteristic of stratum response, and erase the effects of the noise. In this paper we finished prestack invertion in the BYT survey and fractured reservoir depiction in MB survey. By the invertion and multiple attributes crossplot. we can get the stratum profiles and oil indicator profiles which can predict the distribution of the reservoir and oil. In the MB survey, we get orientation and density of fractured reservoir by the azimuthal seismic amplitude and depict the potential oil and gas reservoir. Prestak invertion works better in distinguishing oil and reservoir.

陕北何家集区延长组长4＋5－长6储层特征研究

Abstract： Hejiaji area lies on eastern part of Shanbei Slope in Ordos Basin and the primary oil-bearing bed is Chang 4＋5 and Chang 6 of Yanchang Formation. It is indicated that the sedimentary facies and reservoir characteristics restricted the hydrocarbon accumulation regularity by the geological information. Therefore, Applied with outcrop observation，core description, geophysical logging interpretation, thin section determination, Scanning Electron Microscope, reservoir lithology and physical property analysis and other analytic machinery, the sedimentary facies ,micro-characteristic and master control factors on hydrocarbon reservoir of Yanchang Formation in Hejiaji area are studied deeply by means of sedimentology，reservoir geology and petroleum geology and provide a reliably reference for later prospect . Delta facies are identified in Hejiaji area and of which distributary channels in delta plain microfacies controlled the distribution of sand bodies and accumulation of oil and gas.The distribution of sand bodies distributed from northeast to southwest are dominated by sedimentary facies . It was shown that the sandstones are medium to granule arkose，which the mud matrix is r and including，calcite，the content of matrix is lower and that mostly are cements which are mainly quartz and feldspar overgrowths and chlorite films, in the second place are hydromica and ferrocalcite. All the sandstones have entered a period of late diagenetic stage in which the dominant diagenesis types in the area are compaction, cementation and dissolution. Remnant intergranular porosity and feldspar dissolved pore are main pore types which are megalospore and medium pore. Medium-fine throat, fine throat and micro-fine throat are the mainly throat type. Pore texture can be classified as megalospore and fine throat type, medium-pore and micro-fine throat type mainly, and they are main accumulate interspace in research region. The reservoir of Yanchang Formation in Hejiaji area is low- pore and low- permeability in the mass which have strong heterogeneity in bed, interbedded and plane. Studying the parameter of pore and permeability comprehensively and consulting prevenient study results of evaluation of reservoir, the reservoir is classifiedⅡ，Ⅲ and Ⅳ three types in which the Ⅱand Ⅲ can be divided into Ⅱa and Ⅱb, Ⅲa and Ⅲb respectively. Ⅱb and Ⅲa are the main reservoir type in Hejiaji area which are about 72.73％and 80％percent of whole reservoir and effective reservoir respectively.

砂砾岩油藏精细油藏描述–以准噶尔盆地西北缘八区下乌尔禾组油藏为例

Glutenite reservoir is one of the most important reservoir types in china. Because of its particularity of rock structure and pore structure, it is usually difficult in development, especially for its serious heterogeneity. On the basis of seismic, well logs, core data and production performance, the lower Wuerhe group can be divided into one second-order sequences, two third-order sequences and twenty two subsequences, corresponding to the five stages and twenty two minlayers. In addition, the fault systems are interpreted and the control action of fault systems to reservoir development is also described. The lower Wuerhe formation of 8th district belongs to fluvial-dominated fan delta sedimentation, according to the analysis of well logs, logging data and core data. It can be subdivided into two kinds of subfacies and nine kinds of microfacies. The fan delta plain subfacies mainly consist of braided channel, unconcentrated flow, mud flow and sieve deposit microfacies. The fan delta front subfacies include subaqueous distributary channel, subaqueous interdistributary channel, debris flow, subaqueous barrier and grain flow microfacies. Combined with the regional geological characteristics, the porosity model of lower Wuerhe formation is performed using core data. A permeability model based on the flow zone index is also formed according to the pore throat characteristics and flow property. Finally, the heterogeneity is analyzed. The result shows that the lower Wuerhe formation has a feature of middle-high heterogeneity, and it is controlled by material sources and sedimentary facies belt.

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.

塔里木盆地寒武－奥陶系白云岩类型、成因机理及其孔隙性研究

Cambrian-Ordovician dolostones in Tarim Basin are hydrocarbon reservoir rocks of vital importance. Under the guidance of the theories of sedimentology and the sedimentology of carbonate reservoir, based on the first-hand qualitative and quantitative data especially, combined with micro-study, geochemical and reservoir capacity analysis, and precursor research, the origin and reservoir characteristics of the dolostones were discussed. Based on detailed petrographic investigations, four types of dolostone have been recognized, which are, respecitively, mud-silt-sized dolostones, algal laminated dolostones (ALD), prophyritic dolostone, and neomorphic dolostone. Mud-silt-sized dolostones always presents as laminas together with evaporated signatures, its REE patterns and ΣREE are all close to that of the finely crystalline limestone. This kind of dolomite probably experienced relatively low fluid-rock ratio during diagenesis was formed in hypersaline and oxidizing environment and involved fast dolomitization process. It was dolomitized by evaporated seawater in sabkha environment.The main primary fabrics of algal lamination in algal laminated dolomite (ALD) can still be identified and its ΣREE (21.37) is very close to that of algae. This reveals that ALD was dolomitized during early diagenesis and algae possibly played an important role. The ALD was formed under mediation of organic matter and Mg2+ were supplied by magnesium concentrated algal laminites and sea water. Prophyritic dolostones presents mainly as patchy occurrence and yield the lowest δ13C and Z value. Its ΣREE is much less than that of the finely crystalline limestone. These characteristics reveal that the cloudy cores were dolomitized in shallow early diagenetic environments by pore fluids riched in Mg2+. Whereas the clear rims were likely formed in subsequent burial into deeper subsurface environments, and the Mg2+ needed for further dolomitization possibly was supplied by the transformations of clay minerals. Neomorphic dolostones consist of coarse, turbid crystals and exhibits sucrosic and mosaic textures. It has highest Fe2+ contents and average homogeneous temperature (110.2℃). Collectively, these characteristics demonstrate that the neomorphic dolostones was likely formed by recrystallization of pre-existing dolomites during deep burial. The ΣREE of the four types of dolostone distinctly differentiates from each other. However, their REE patterns are all enriched in LREE, depleted in HREE and have Eu negative anomalies. Its ΣREE 13.64 ppm, less than 1/4 of finely crystalline limestone, and ranks the lowest in the 4 types.These characteristics are comparable to those of finely crystalline limestone, and are mainly infuenced by the sea water. These four types of dolostone show similar REE mobility behaviour and no significant fractionation, althouth they have been subjected to evidently different diageneses. Seven main pore types are identified in the dolostones , which are fenestral, moldic, intercrystal, dissolved，breccia, dissolved breccia and stylolite pores. Fenestral pores are primary and the others are secondary. The dissolved pores and intercrystal pores are the most important reservoir spaces and followed by breccias and dissolved breccia pores, and the moldic and fenestral pores are less important. Stylolites can enhance permeability of reservoir rocks in one hand, for the other hand, the capacity of reservoir and permeability are enhanced and then better reservoir rocks can be formed when they are combined with patchy dolostones. The relationship between porosity and the type of dolostones is that the dissolved neomorphic dolostones have the highest porosity of 3.65%, than followed by dissolved Mud-silt-sized dolostones of 3.35%. The mud-silt-sized dolostones without dissolution have the lowest porosity of 0.90%. Moreover, the porosity of prophyritic dolostones and the neomorphic dolostones without dissolution are lower, respectively 1.675% and 1.41%. Although algal laminated dolostones consist of euhedral crystals and riched in intercrystal pores, its porosity just yields 1.20%. The relationship between permeability and the type of dolostones is that that algal laminated dolostones have the highest permeability of 0.462mD and followed by 0.065mD of prophyritic dolostones. Dissolution have no significant influence on the permeability of neomorphic dolostones and this presented by the permeability of dissolved and non-dissolved are very close, respectively 0.043mD and 0.062mD. No matter dissolved or not, mud-silt-sized dolostones are much less permeable. The permeability of non-dissolved and dissolved are 0.051mD and 0.016mD. Collectively, in the study area, neomorphic dolostones can form high quality reservoir.

松辽徐家围子断陷层序地层充填模式及含油气性特征

Based on the principle and method of sequence, the author describes the sequence-filling model of the rifting basin of Xujiaweizi and its gas exploration potential. The object of this paper belongs to the area around Shengping-Wangjiatun anticline. Its srtatigraphy includes Huoshiling Formation (neutral and basic volcanic rocks), Shahezi Formation (coal bedding and mud and some sandstone) and Yingcheng Formation from bottom to top. These stratigraphy units are defined by author as mesosequences respectively. The author emphasizes that the main control factors of sequence change with the types of basin and stage of basin. So the sequence is researched according to the types of basin. This viewpoint is very new, and it is consistent with the principle of sequence. Volcanic action is very frequent and acute, topography difference is obvious. Between the volcanic events, Shahezi Formation is formed, which mainly consists-of sedimentary rocks. Based on the datum from seismic section and drilling core and well-logging, the author analyzes the single unit and unit set and system tract and sedimentary fancies, then, according to the accommodation space change and marking of sequence boundary, Shahezi Formation is divided into two Third-scale sequences. The sedimentary fancies and depth distribution are described. The author also pointed out that the volcanic rocks consume the accommodation space, so volcanic rocks can influence the development of sequence. Based on the concept of accommodation space, the author put volcanic rocks into sequence frame, which normally consists of sedimentary rocks. The topography of volcanic is controlled by lithology of volcanic rocks, the pattern of volcanic eruption and the topography before volcanic eruption. The topography of volcanic can influence sedimentation and the filling pattern of sedimentary rocks. The author describes the composition and lithology fancies and depth distribution of volcanic rocks. The volcanic rocks and Volcanic building, volcanic structure is recognized on seismic section. The author paid a special attention to the relationship between sedimentation and volcanism. Finally, the author analyses the combination of source-reservoir-cover unit in sequence frame. The mudstone of Shahezi Formation has a great depth, the Kerogene in it belongs to type II and III, which tends to produce gas. The Yingcheng Formation lies between Shahezi Formation and Denglouku Formation, belonging to good reservoir. The volcanic rocks of Huoshiling Formation often formed high building, which can capture the gas produced from Shahezi Formation. The stratigraphy of rifting basin of Xujiaweizi has the great potential of gas exploration. This paper claims the following creative points: 1. The author applied the principle and method of sequence to rifting basin, greatly extending its research area and topic issues. 2. The author pointed out that basin of different type and of different stage has a different type of sequence. This is caused by the different main control factors of sequence. 3. Put volcanic rocks into the sequence frame, discussing the probability of regarding the volcanic rocks as the component of sequence, dealing with the relationship between sedimentation and volcanism and its influence to the source-reservoir-cover system. 4. The author pointed out that the filling pattern of rifting basin are determined by the filling pattern of megasequence, whose filling pattern is determined by the filling pattern of system tract and the change of accommodation space.

吐合盆地鲁克沁构造带断块油藏形成机制及油藏预测

Lukeqin arc belt is a compound structure generated by multi-movements and composed of 6 sub-structural zones, which are connected by Huoyanshan Mountain. General characteristics of the arc belt are multi-patterns of structure, multi-phases for petroleum, multi-types of trap and multi-layers for reservoirs. As a part of the eastern Lukeqin arc belt located on the south of Taibei depression, Lukeqin structural zone behaves as a complex faulted-fold zone, in which the formation and distribution of hydrocarbons are controlled by structures. As the dominant source of dynamics for the second migration of hydrocarbon, structure stress field is closely related with the potentials of hydrodynamics. Results derived from the simulations of stress field by finite element method indicate that the northwest tending faults prefer seal to the northeast tending ones. The reason is that the northwest tending faults were squeezed more strongly than the northeast tending ones. Therefor, the northeast tending faults become always the paths for oil to migrate southeastward. Lukeqin structural zone is the main site for oil to concentration because it is surrounded by high stress. Situated on the front of the foreland basin of Turpan-Hami, Lukeqing arc belt is a dam to hold back the southward migrating oil from Shengbei depression. The axis line of Shenquan-Shengnan-Yanmuxi, Lukeqin and Yubei controls the migrating paths and concentrating process of oil and gas. Results derived from stress simulation and structure analyses indicate consistently that both Yubei and Lukeqin structural zones are the favorite areas for oil to migrate. The generally southward paths for oil to migrate out of Taibei depression can be two ways. One of them is from Taibei depression to Yubei structural zone and the other is from Taibei depression to Lukeqin structural zone. By the both ways, oil migrated upward along the faults and southeastward along the structural axis to concentrate in either Permian or Triassic system. The newly ascertained path for oil migration, which is accurately southeastward instead of coarsely southward, indicates the directions for further explorations on the compound Lukeqin block zone. Five kinds of seal models of fault are all found in Lukeqin block zone by studying the seal features of faults occurred in the zone. Having studied the fault seal and their controlling factors by fuzzy set method, the paper deems that the northwest tended faults are better than the northeast tended ones for oil to concentrate. The most important factors to decide the seal extent of faults in this zone are the characteristics of main stress and fluids instead of capillary pressure differences between the two sides of fault and smear mud factors. There exist seal differences not only between the faults of different time but also between the sections within a fault due to the variation of depths, strata and positions. The general distribution rules of reservoirs were dominated by the seal characteristics of a fault during the time reservoirs formed. While the current features of fault seal decide the conservation of reservoirs and heights of oil accumulations. Seal or not of a fault is not absolute because the essential for fault to seal is the distribution of permeability of fault zone. Therefor, the multi cyclical activities of faults create the space-time variation of seal features of the fault. Totally, the seal extent of the faults within the area is not as perfect as to accumulate ordinary crude. Crude oil can only be sealed when it becomes viscous. Process for crude oil to become viscous and viscous happened strongly because of the fault-fold movements. Shallowly burying and even revealing of the objective layers of the reservoirs made the crude oil to be thickened by water washing biologically degradation and oxidation degradation. The northwestward deepening during or after the reservoir formation of the structural zone provided the power for oil to migrate one or more times. The main reason for oil accumulation is the formation of Lukeqin block zone during Xishanyao stage, middle Jurassic Period, Early Yanshanian Movement. While the main reason for reservoir conservation is the placidity of Triassic blocks after the formation of reservoirs. Contrasting to former opinions, it is concluded that the reservoirs in Lukeqin zone, including viscous reservoirs, were formed by one time but not more times. So the author proposes the opinion that the reservoirs of viscous oil were formed by viscous oil migration under the conditions of aptitude sets of fault seals controlled by fluid and other factors. To grope the distribution rules outside Taibei depression and discuss the formation mechanism of Anjurassic reservoirs, it is necessary to study the dominate factors for the formation of reservoirs in Lukeqin structural zone such as structural stress, fault seals and thickening mechanism of crude oil. Also, the necessary studies are the key to break through the Taibei depression and Anjurassic systems. Therefor, they are significant for the future exploration and reserve increasing of hydrocarbon within the Turpan-Hami basin. The paper studied the distribution rules of block reservoirs and forecasted the favorable zones for further exploration in Turpan-Hami basin. Conclusions can be useful for not only the exploration in the area but also the theory consult in the adjacent areas.

东海陆架盆地西南部烟囱构造与油气运聚关系研究

In recent years, chimney structure has been proved one of important indicators and a useful guide to major petroleum fields exploration through their exploration history both at home and abroad. Chimney structure, which has been called "gas chimney" or "seismic chimney", is the special fluid-filled fracture swarm, which results from the boiling of active thermal fluid caused by abruptly decreasing of high pressure and high temperature in sedimentary layers of upper lithosphere. Chimney structure is well developed in continental shelf basin of East China Sea, which indicates the great perspectives of petroleum resources there. However, the chimney structure also complicated the petroleum accumulation. So the study of chimney structure on its formation, its effect on occurrence and distribution of petroleum fields is very important not only on theoretical, but also on its applied research. It is for the first time to make a clear definition of chimney structure in this paper, and the existence and practical meaning of chimney structure are illustrated. Firstly, on the viewpoint of exploration, this will amplify exploration area or field, not only in marine, but also on continent. Secondly, this is very important to step-by-step exploration and development of petroleum fields with overpressure. Thirdly, this will provide reference for the study on complex petroleum system with multi-sources, commingled sources and accumulation, multi-stage accumulations, and multi-suits petroleum system in the overlay basin. Fourthly, when the thermal fluid enters the oceanic shallow layer, it can help form gas hydrate under favorable low-temperature and high-pressure conditions. Meanwhile, the thermal fluid with its particular component and thermal content will affect the physical, chemical and ecological environments, which will help solving the problem of global resources and environment. Beginning from the regional tectonic evolution characteristics, this paper discussed the tectonic evolution history of the Taibei depression, then made an dynamical analysis of the tectonic-sedimentary evolution during the Mesozoic and Cenozoic for the East China Sea basin. A numerical model of the tectonic-thermal evolution of the basin via the Basin-Mod technique was carried out and the subsidence-buried history and thermal history of the Taibei depression were inverse calculated: it had undergone a early rapid rift and sag, then three times of uplift and erosion, and finally depressed and been buried. The Taibei depression contains a huge thick clastic sedimentary rock of marine facies, transitional facies and continental facies on the complex basement of ante-Jurassic. It is a part of the back-arc rifting basins occurred during the Mesozoic and Cenozoic. The author analyzed the diagenesis and thermal fluid evolution of this area via the observation of cathodoluminescence, scanning electron microscope and thin section, taking advantage of the evidences of magma activities, paleo-geothermics and structural movement, the author concluded that there were at least three tectonic-thermal events and three epochs of thermal-fluid activities; and the three epochs of thermal-fluid activities were directly relative to the first two tectonic-thermal events and were controlled by the generation and expulsion of hydrocarbon in the source rock simultaneously. Based on these, this paper established the corresponding model between the tectonic-thermal events and the thermal-fluid evolution of the Taibei Depression, which becomes the base for the study on the chimney structures. According to the analyses of the gas-isotope, LAM spectrum component of fluid inclusion, geneses of CO_2 components and geneses of hydrocarbon gases, the author preliminarily verified four sources of the thermal fluid in the Taibei Depression: ① dehydration of mud shale compaction, ② expulsion of hydrocarbon in the source rock; ③ CO_2 gas hydro-thermal decomposition of carbonatite; ④magma-derived thermal fluid including the mantle magma water and volatile components (such as H_2O, CO_2, H_2S, SO_2, N_2 and He etc.). On the basis of the vitrinite reflectance (Ro), homogenization temperature of fluid inclusion, interval transit time of major well-logging, mud density of the wells, measured pressure data and the results of previous studies, this paper analyzed the characteristics of the geothermal fields and geo-pressure fields for the various parts in this area, and discussed the transversal distribution of fluid pressure. The Taibei depression on the whole underwent a temperature-loss process from hot basin to cold basin; and locally high thermal anomalies occurred on the regional background of moderate thermal structure. The seal was primarily formed during the middle and late Paleocene. The overpressured system was formed during the middle and late Eocene. The formation of overpressured system in Lishui Sag underwent such an evolutionary process as "form-weaken-strengthen-weaken". Namely, it was formed during the middle and late Eocene, then was weakened in the Oligocene, even partly broken, then strengthened after the Miocene, and finally weakened. The existence of the thermal fluid rich in volatile gas is a physical foundation for the boiling of the fluid, and sharply pressure depletion was the major cause for the boiling of the fluid, which suggests that there exists the condition for thermal fluid to boil. According to the results of the photoelastic simulation and similarity physical experiments, the geological condition and the formation mechanism of chimnestructures are summarized: well compartment is the prerequisite for chimney formation; the boiling of active thermal fluid is the original physical condition for chimney formation; The local place with low stress by tension fault is easy for chimney formation; The way that thermal fluid migrates is one of the important factors which control the types of chimney structures. Based on where the thermal fluid come from and geometrical characteristics of the chimney structures, this paper classified the genetic types of chimney structures, and concluded that there existed three types and six subtypes chimney structures: organic chimney structures generated by the hydrocarbon-bearing thermal fluid in middle-shallow layers, inorganic and commingling-genetic chimney structures generated by thermal fluid in middle-deep layers. According to the seismic profiles interpretations, well logging response analysis and mineralogical and petrological characteristics in the study area, the author summarized the comprehensive identification marks for chimney structures. Especially the horizon velocity analysis method that is established in this paper and takes advantage of interval velocity anomaly is a semi-quantitative and reliable method of chimney structure s identification. It was pointed out in this paper that the occurrence of the chimney structures in the Taibei depression made the mechanism of accumulation complicated. The author provided proof of episodic accumulation of hydrocarbon in this area: The organic component in the boiling inclusion is the trail of petroleum migration, showing the causality between the boiling of thermal fluid and the chimney structures, meanwhile showing the paroxysmal accumulation is an important petroleum accumulation model. Based on the evolutionary characteristics of various types of chimney structures, this paper discussed their relationships with the migration-accumulation of petroleum respectively. At the same time, the author summarized the accumulating-dynamical models associated with chimney structures. The author analyzed such accumulation mechanisms as the facies state, direction, power of petroleum migration, the conditions of trap, the accumulation, leakage and reservation of petroleum, and the distribution rule of petroleum. The author also provides explanation for such practical problems the existence of a lot of mantle-derived CO_2, and its heterogeneous distribution on plane. By study on and recognition for chimney structure, the existence and distribution of much mantle-derived CO_2 found in this area are explained. Caused by tectonic thermal activities, the deep magma with much CO_2-bearing thermal fluid migrate upward along deep fault and chimney structures, which makes two wells within relatively short distance different gas composition, such as in well LF-1 and well LS36-1-1. Meanwhile, the author predicted the distribution of petroleum accumulation belt in middle-shallow layer for this area, pointed out the three favorable exploration areas in future, and provided the scientific and deciding references for future study on the commingling-genetic accumulation of petroleum in middle-deep layer and the new energy-gas hydrate.