利用接收函数方位变化研究地壳各向异性

Because of its sensitivity to the velocity discontinuity of the earth, receiver function technique has become a routine procedure used to probe interior structure of the earth. Receiver functions contain anisotropic information of the earth’s interior, however, traditional receiver function techniques such as migration imaging and waveform inversion method, which are based on isotropic media assumption, can not effectively extract the anisotropy information contained in the azimuth variation pattern. Only by using the anisotropic media, e.g. a model with symmetric axis of arbitrary orientation, computing the response, can we obtain the detailed anisotropy information hidden in the radial and transversal receiver function. Focusing on the receiver function variation pattern changing wtih different back azimuths, we introduced different kinds of symmetric systems of seismic anisotropy used often, and summarized some possible causes of anisotropy formation. We show details about how to calculate the response of a stratified anisotropy model with symmetric axis of arbitrary orientation. We also simulated receiver functions among different models and analyzed how the changing of anisotropic parameters influence the azimuth variation pattern of receiver functions. The anisotropy study by receiver function analysis was applied to Taihang Mountain Range (TMR) in North China in this thesis. The maximum entropy spectrum deconvolution technique was used to extract radial and transversal receiver functions from the waveforms of 20 portable seismic stations deployed in TMR. Considering the signal-to-noise ratio and the azimuth coverage, we got the variation pattern of receiver functions for 11 stations. After carefully analyzing the pattern of the receiver functions that we got, we obtained the reliable evidence on the existence of anisotropy in the shallow crust in TMR. Our results show that, although the thickness of the upper crustal layer is only about 1 km, the layer shows a strong anisotropy with magnitude of 8~15%; in the deeper of crust, the magnitudes of anisotropy is about 3%~5%, showing a pattern with fast-symmetric-axis. The crust anisotropy beneath TMR in North China obtained in this study also shows a significant difference in both the lateral and vertical scale, which might imply a regional anisotropy characteristic in the studied region.

KEL-TI介质的地震波场响应与成像方法研究

To deal with the problems in multi-component converted seismic wave exploration in coal fields, the wave propagating features and imaging methods of multi-component converted waves in coal measure strata are researched in this thesis firstly. The relations between viscoelasticity and anisotropy in coal measure strata are analyzed to build KEL-TI model, and which seismic wave propagating and attenuating features are researched. The disadvantages of converted wave imaging methods based on common converted point gather are analyzed and constant velocity no NMO converted wave imaging method based on common scattering point gather is put forward, according to Huygens-Fresnel principle, which applicabilities in the elastic isotropic, elastic TI and KEL-TI situations are discussed. To different model simulation data, the common scattering point gathers’ and stacked profiles’ features are analyzed. The results show that the method can image compressional waves and converted waves with high precision. Secondly, the resolution enhancing theories and methods of converted wave are researched by Rayleigh wave suppressing, converted wave static correction and poststack inverse-Q filtering. 1) The polarization filter is designed by the instantaneous polarization information of seismic waves, and the Rayleigh wave suppressing method is researched. From the spectrum analysis before and after filtering, it can be derived that the amplitudes are kept relatively. 2) To constant velocity no NMO converted wave imaging method, the static correction method based on common equivalent offset point gather is put forward and tested to the actual converted waves. 3) The relation between equivalent quality factor of converted wave, compressional wave quality factor and the ratio of compressional to shear wave velocity is derived. The compressional wave quality inversion method by first arrivals of none-offset VSP is researched, and which is then transformed to the equivalent quality factor to perform inverse-Q filtering of actual converted waves. The result has shown that the method can recover the high frequency energy of converted waves. At last, the theories and methods researched in this thesis are practiced to the 3D3C seismic exploration in Guqiao coal mine in Huainan and achieve good results.

压力和铁含量对铁方镁石(Mg1-xFex)O(x<=0.25)弹性常数影响的第一性原理研究

By first principle methods based on density functional theory (DFT),the equation of state(EOS) and elastic constants of both periclase and ferropericlase are calculated. The pressure and iron doping effects on the elastic constants of ferropericlase are investigated systematically. Firstly, we calculate the elastic constants of periclase and compare the obtained results with experimental data and other theoretical calculations, which shows a encouraging consistence and demonstrates the practicability of first-principle methods. Secondly, by adding iron into periclase crystal model, we build up ferropericlase with iron contents ranging from 0% to 25% mole percent. The corresponding elastic constants are calculated in a large pressure range(0~120GPa). Emphatically, the strong correlation of 3d electrons in transitional elements, such as iron, is difficult to treat in first-principle methods for a long time. The current solution is to make additional correction. During the initial stage of this study, the strong correlation of 3d electrons in iron is not considered, and we observed that addition of iron decreases the volume of ferropericlase, which is totally contradictory to the experimental data. By applying LDA+U approximation in order to solve the strongly correlated 3d electron of iron, we observed the expansion of volume by iron as expected. On the basis of the LDA+U approximation, the elastic constants of ferropericlase are calculated. After a detailed analysis of data obtained from theoretical calculations, we have reached the following conclusions:(1)pressure imposes positive effects on all elastic constants, and the degree of effects is C11>C12>C44. (2) Iron has no distinctive effects on C11 and C12, although some fluctuations are observed around 60GPa. However, iron has obvious softening effects on C44 The softening effects on C44 are intensified as pressure increases. Above the 100GPa, the effects increase greatly, even surpasses the pressure's positive effects in ferropericlase crystal models with iron mole percent of having 12.5%, 18.75% and 25% iron content. (3)As to the modulus deprived from elastic constants, iron has no effect on the adiabatic bulk module BS, only a little fluctuation around 60GPa. We find iron's softening effects on shear modulus G. (4)We find out that, compared with low iron content, elastic constants with iron content approaching 25mole% is consistently fluctuated，which may be caused by the limitations of the LDA+U approximation method itself. (5)We investigate the pressure and Fe doping effects on elastic anisotropy factor（A=(2C44+C12-C11)/C11） of ferropericlase and find out that iron contents will lower the critical isotropic pressure. At the same pressure, when the pressure is below the isotropic pressure, iron softens the anisotropy factor ; when pressure surpasses the isotropic pressure, iron increases the anisotropy factor.

旋转轴对称介质中的qP波一阶射线追踪

Elastic anisotropy is a very common phenomenon in the Earth’s interior, especial for sedimentary rock as important gas and oil reservoirs. But in the processing and interpretation of seismic data, it is assumption that the media in the Earth’s interior is completely elastic and isotropic, and then the methods based on isotropy are used to deal with anisotropic seismic data, so it makes the seismic resolution lower and the error on images is caused. The research on seismic wave simulation technology can improve our understanding on the rules of seismic wave propagation in anisotropic media, and it can help us to resolve problems caused by anisotropy of media in the processing and interpretation of seismic data. So researching on weakly anisotropic media with rotated axis of symmetry, we study systematically the rules of seismic wave propagation in this kind of media, simulate the process with numerical calculation, and get the better research results. The first-order ray tracing (FORT) formulas of qP wave derived can adapt to every anisotropic media with arbitrary symmetry. The equations are considerably simpler than the exact ray tracing equations. The equations allow qP waves to be treated independently from qS waves, just as in isotropic media. They simplify considerably in media with higher symmetry anisotropy. In isotropic media, they reduce to the exact ray tracing equations. In contrast to other perturbation techniques used to trace rays in weakly anisotropic media, our approach does not require calculation of reference rays in a reference isotropic medium. The FORT-method rays are obtained directly. They are computationally more effective than standard ray tracing equations. Moreover the second-order travel time corrections formula derived can be used to reduce effectively the travel time error, and improve the accuracy of travel time calculation. The tensor transformation equations of weak-anisotropy parameters in media with rotated axis of symmetry derived from the Bond transformation equations resolve effectively the problems of coordinate transformation caused by the difference between global system of coordinate and local system of coordinate. The calculated weak-anisotropy parameters are completely suitable to the first-order ray tracing used in this paper, and their forms are simpler than those from the Bond transformation. In the numerical simulation on ray tracing, we use the travel time table calculation method that the locations of the grids in the ray beam are determined, then the travel times of the grids are obtained by the reversed distance interpolation. We get better calculation efficiency and accuracy by this method. Finally we verify the validity and adaptability of this method used in this paper with numerical simulations for the rotated TI model with anisotropy of about 8% and the rotated ORTHO model with anisotropy of about 20%. The results indicate that this method has better accuracy for both media with different types and different anisotropic strength. Keywords: weak-anisotropy, numerical simulation, ray tracing equation, travel time, inhomogeneity

复杂介质边界元法数值模拟研究

A major impetus to study the rough surface and complex structure in near surface model is because accuracy of seismic observation and geophysical prospecting can be improved. Wave theory study about fluid-satuated porous media has important significance for some scientific problems, such as explore underground resources, study of earth's internal structure, and structure response of multi-phase porous soil under dynamic and seismic effect. Seismic wave numerical modeling is one of the effective methods which understand seismic propagation rules in complex media. As a numerical simulation method, boundary element methods had been widely used in seismic wave field study. This paper mainly studies randomly rough surface scattering which used some approximation solutions based on boundary element method. In addition, I developed a boundary element solution for fluid saturated porous media. In this paper, we used boundary element methods which based on integral expression of wave equation to study the free rough surface scattering effects of Kirchhoff approximation method, Perturbation approximation method, Rytov approximation method and Born series approximation method. Gaussian spectrum model of randomly rough surfaces was chosen as the benchmark model. The approximation methods result were compared with exact results which obtained by boundary element methods, we study that the above approximation methods were applicable how rough surfaces and it is founded that this depends on and ( here is the wavenumber of the incident field, is the RMS height and is the surface correlation length ). In general, Kirchhoff approximation which ignores multiple scatterings between any two surface points has been considered valid for the large-scale roughness components. Perturbation theory based on Taylor series expansion is valid for the small-scale roughness components, as and are .Tests with the Gaussian topographies show that the Rytov approximation methods improves the Kirchhoff approximation in both amplitude and phase but at the cost of an extra treatment of transformation for the wave fields. The realistic methods for the multiscale surfaces come with the Born series approximation and the second-order Born series approximation might be sufficient to guarantee the accuracy of randomly rough surfaces. It could be an appropriate choice that a complex rough surface can be divided into large-, medium-, and small-scale roughness components with their scattering features be studied by the Kirchhoff or Rytov phase approximations, the Born series approximation, and the perturbation theory, respectively. For this purpose, it is important to select appropriate parameters that separate these different scale roughness components to guarantee the divided surfaces satisfy the physical assumptions of the used approximations, respectively. In addition, in this paper, the boundary element methods are used for solving the porous elastic wave propagation and carry out the numerical simulation. Based on the fluid-saturated porous model, this paper analyses and presents the dynamic equation of elastic wave propagation and boundary integral equation formulation of fluid saturated porous media in frequency domain. The fundamental solutions of the elastic wave equations are obtained according to the similarity between thermoelasticity and poroelasticity. At last, the numerical simulation of the elastic wave propagation in the two-phase isotropic media is carried out by using the boundary element method. The results show that a slow quasi P-wave can be seen in both solid and fluid wave-field synthetic seismograms. The boundary element method is effective and feasible.

叠前时间偏移：各向异性、多次波衰减及应用

At present, in order to image complex structures more accurately, the seismic migration methods has been developed from isotropic media to the anisotropic media. This dissertation develops a prestack time migration algorithm and application aspects for complex structures systematically. In transversely isotropic media with a vertical symmetry axis (VTI media), the dissertation starts from the theory that the prestack time migration is an approximation of the prestack depth migration, based on the one way wave equation and VTI time migration dispersion relation, by combining the stationary-phase theory gives a wave equation based VTI prestack time migration algorithm. Based on this algorithm, we can analytically obtain the travel time and amplitude expression in VTI media, as while conclude how the anisotropic parameter influence the time migration, and by analyzing the normal moveout of the far offset seismic data and lateral inhomogeneity of velocity, we can update the velocity model and estimate the anisotropic parameter model through the time migration. When anisotropic parameter is zero, this algorithm degenerates to the isotropic time migration algorithm naturally, so we can propose an isotopic processing procedure for imaging. This procedure may keep the main character of time migration such as high computational efficiency and velocity estimation through the migration, and, additionally, partially compensate the geometric divergence by adopting the deconvolution imaging condition of wave equation migration. Application of this algorithm to the complicated synthetic dataset and field data demonstrates the effectiveness of the approach. In the dissertation we also present an approach for estimating the velocity model and anisotropic parameter model. After analyzing the velocity and anisotropic parameter impaction on the time migration, and based on the normal moveout of the far offset seismic data and lateral inhomogeneity of velocity, through migration we can update the velocity model and estimate the anisotropic parameter model by combining the advantages of velocity analysis in isotropic media and anisotropic parameter estimation in VTI media. Testing on the synthetic and field data, demonstrates the method is effective and very steady. Massive synthetic dataset、2D sea dataset and 3D field datasets are used for VTI prestack time migration and compared to the stacked section after NMO and prestack isotropic time migration stacked section to demonstrate that VTI prestack time migration method in this paper can obtain better focusing and less positioning errors of complicated dip reflectors. When subsurface is more complex, primaries and multiples could not be separated in the Radon domain because they can no longer be described with simple functions (parabolic). We propose an attenuating multiple method in the image domain to resolve this problem. For a given velocity model，since time migration takes the complex structures wavefield propagation in to account, primaries and multiples have different offset-domain moveout discrepancies, then can be separated using techniques similar to the prior migration with Radon transform. Since every individual offset-domain common-reflection point gather incorporates complex 3D propagation effects, our method has the advantage of working with 3D data and complicated geology. Testing on synthetic and real data, we demonstrate the power of the method in discriminating between primaries and multiples after prestack time migration, and multiples can be attenuated in the image space considerably.

三维非均匀各向异性介质中的纵波走时反演研究

Many observations show that seismic anisotropy is very common in the crust and upper mantle of the Earth. Seismic anisotropy can provide some clue about the changing and transporting process inside the earth. in recent years, abundant earthquake travel time data are accumulated, computers become more powerful, and these make the inversion of earthquake travel time data practical. In this thesis we studied the theory of elastic wave in anisotropic media, some formule for travel time inversion were derived. We present an iterative procedure to determine 21 elastic parameters from qP wave travel times. No a priori assumptions about heterogeneity and anisotropy of the model are made. The procedure is suitable for the case when we know nothing about the symmetry of anisotropy of the media, as well as for the case of earthquake travel time inversion which may contain various symmetry of anisotropy. The procedure is tested with a synthetic multiple-source offset VSP experiment. The results proved that the formulae are correct, and the procedure is practical. The results and the related theory indicate that the anisotropic inversion needs more rays than isotropic case. For a 2-D weak anisotropic (WA) medium, we need at least 5 rays in different directions to retrieve the elastic parameters on one grid point, and for a 3-D WA medium we need at least 15 rays in different directions to retrieve the elastic parameters on one grid point. The results also indicate that the starting background velocity has no influence on the final results, at least for the model we specified. Our results also show that insufficient illumination coverage will slow down the convergence rate, and make the results more sensitive to noise. We apply the procedure to a set of field travel time data. The data is from an artificial seismic observation. This observation is for locating micro-seismic events around a tunnel, its purpose is to find out if the digging process and the stress condition around the tunnel can generate micro-cracks. The size of this area is around 100m. The anisotropy derived from qP travel times is the same as the anisotropy showed by apparent velocities, and is also consistent with the anisotropy derived from S-wave splitting phenomena.

各向同性与各向异性介质中地震波旅行时正演模拟与反演成像

By seismic tomography, interesting results have been achieved not only in the research of the geosphere with a large scale but also in the exploration of resources and projects with a small scale since 80'. Compared with traditional inversion methods, seismic tomography can offer more and detailed information about subsurface and has been being paid attention by more and more geophysicists. Since inversion based on forward modeling, we have studied and improved the methods to calculate seismic traveltimes and raypaths in isotropic and anisotropic media, and applied the improved forward methods to traveltime tomography. There are three main kinds of methods to calculate seismic traveltime field and its ray path distribution, which are ray-tracing theory, eikonal equation by the finite-difference and minimum traveltime tree algorithm. In ray tracing, five methods are introduced in the paper, including analytic ray tracing, ray shooting, ray bending, grid ray tracing and rectangle grid ray perturbation with three points. Finite-difference solution of eikonal equation is very efficient in calculation of seismic first-break, but is awkward in calculation of reflection traveltimes. We have put forward a idea to calculate traveltimes of reflected waves using a combining way of eikonal equation method and other one in order to improve its capability of dealing with reflection waves. The minimum traveltime tree algorithm has been studied with emphases. Three improved algorithms are put forward on the basis of basic algorithm of the minimum traveltime tree. The first improved algorithm is called raypath tracing backward minimum traveltime algorithm, in which not only wavelets from the current source but also wavelets from upper source points are all calculated. The algorithm can obviously improve the speed of calculating traveltimes and raypaths in layered or blocked homogeneous media and keep good accuracy. The second improved algorithm is raypath key point minimum traveltime algorithm in which traveltimes and raypaths are calculated with a view of key points of raypaths (key points of raypths mean the pivotal points which determine raypaths). The raypath key point method is developed on the basis of the first improved algorithm, and has better applicability. For example, it is very efficient even for inhomogeneous media. Another improved algorithm, double grid minimum traveltime tree algorithm, bases upon raypath key point scheme, in which a model is divided with two kinds of grids so that the unnecessary calculation can be left out. Violent undulation of curved interface often results in the phenomenon that there are no reflection points on some parts of interfaces where there should be. One efficacious scheme that curved interfaces are divided into segments, and these segments are treated respectively is presented to solve the problem. In addition, the approximation to interfaces with discrete grids leads to large errors in calculation of traveltimes and raypaths. Noting the point, we have thought a new method to remove the negative effect of mesh and to improve calculation accuracy by correcting the traveltimes with a little of additional calculation, and obtained better results.

弱各向异性介质中传播的地震波及其速度重建

We begin our studies to make the best of information of seismic data and carry out the description of cracks parameters by extracting anisotropic information. The researching contents are: (1) velocity and polarization anomaly of seismic wave (qP and qSV wave) in weak anisotropic media; (2) reflection seismic synthetic record in anisotropic media; (3) multiple scattering induced by cracks; (4) anisotropic structure inversion and velocity reconstruction with VSP (Vertical Seismic Profile) data; (5) multi-parameters analysis of anisotropy in time-domain and depth-domain. Then we obtain results as follows: (1) We achieve approximate relation of qP and qSV wave's velocity and polarization property in weak anisotropic media. At the same time, we calculate anisotropic velocity factors and polarization anomaly of several typical sedimentary rocks. The results show there are different anisotropic velocity factors and polarization anomaly in different rocks. It is one of the primary theoretical foundation which is expected to identify lithology; (2) We calculate reflection seismic synthetic record with theoretical model; (3) We simulate scattering induced by cracks with Boundary Element Method. Numerical studies show that in the presence of cracks; spatial and scale-length distributions are important and cannot be ignored in modeling cracked solids; (4) From traveltimes information of VSP data, we study the velocity parameter inversion of seismic wave under isotropic and anisotropic models, and its result indicate that the inversion imaging under anisotropic model will not destroy the original features of isotropic model, but it will bring on some bigger error if we adopt the method of isotropic model for anisotropic model data. Further more, basing on the study we develop the CDP mapping technology of reflecting structure under isotropic and anisotropic models, and we process real data as a trial of the methods; (5) We study the problem of initial model reconstruction of anisotropic parameters structure represented by Anderson parameter in depth domain for surface data.

各向异性介质中的地震面波和S波分裂

Surface wave propagation in the anisotropic media and S-wave splitting in China mainland are focused in this M.S. dissertation. We firstly introduced Anderson parameters in the research of surface wave propagation in the anisotropic media were deduced, respectively. By applying the given initial model to the forward calculation of Love wave, we compared dispersion curves of Love wave in the anisotropic media with the one in the isotropic media. the results show that, although the two kind of results are similar with each other, the effect of anisotropy can not be neglected. Furthermore, the variation of anisotropy factors will result in the variation of dispersion curves, especially for high-mode one. The method of grid dispersion inversion was then described for further tectonic inversion. We also deduced inversion equation on the condition that the layered media is anisotropic, and calculated the phase-velocity partial derivatives with respect to the model parameters, P- and S-wave velocities, density, anisotropic parameters for Rayleigh wave and Love wave. Having analyzed the results of phase-velocity partial derivatives, we concluded that the derivatives within each period decreased with the depth increasing, the phase-velocity of surface wave is sensitive to the S-wave velocities and anisotropic factors and is not sensitive to the densities of layers. Dispersion data of Love wave from the events occurred during the period from 1991 to 1998 around the Qinghai and Tibet Plateau, which magnitudes are more than 5.5, have been used in the grid dispersion inversion. Those data have been preprocessed and analyzed in the F-T domain. Then the results of 1°*1° grid dispersion inversion, the pure path dispersion data, in the area of Qianghai and Tibet Plateau were obtained. As an example, dispersion data have been input for the tectonic inversion in the anisotropic media, and the results of anisotropic factors under the region of Qianghai and Tibet Plateau were initially discussed. As for the other part of this dissertation. We first introduced the phenomena of S-wave splitting and the methods for calculation the splitting parameters. Then, We applied Butterworth band-pass filter to S-wave data recorded at 8 stations in China mainland, and analyzed S-wave splitting at different frequency bands. The results show the delay time and the fast polarization directions of S-wave splitting depend upon the frequency bands. There is an absence of S-wave splitting at the station of Wulumuqi (WMQ) for the band of 0.1-0.2Hz. With the frequency band broaden, the delay time of S-wave splitting decreases at the stations of Beijing (BJI), Enshi (ENH), Kunming (KMI) and Mudanjiang (MDJ); the fast polarization direction at Enshi (ENH) changes from westward to eastward, and eastward to westward at Hailaer (HIA). The variations of delay time with bands at Lanzhou (LZH) and qiongzhong (QIZ) are similar, and there is a coherent trend of fast polarization directions at BJI, KMI and MDJ respectively. Initial interpretations to the results of frequency band-dependence of S-wave splitting were also presented.

Lg尾波衰减成像研究——北京及邻区衰减成像

With the development of the technology of earthquake observation, more and more researchers work at many fields' of seismicity using seismic kinetic property, as the result, the study of attenuation has also made great progress, especially in the mechanism of the attenuation and the physical process. Aki put forward single back scattering theory to explain the forming of the seismic coda wave in 1969. Then, researchers started to develop the study in seismic scattering and attenuation. My thesis is also based on that theory. We assume that the Lg wave is a superposition fo high-mode surface waves, the coda of Lg is caused by scattering. Sato proposed Single Isotropic Scattering model (SIS model) to interpreted the scatter property, and he also formulated the geometrical spreading term. Then Xie (1988) developed the single spectral-ratio (SSR) method to obtain the Lg coda Q and the frequency dependent factor n. Later, he get to lateral images in the area of scatter ellipse. SSR method is explored and used in the study of Lg coda waves of regional earthquakes in my thesis. Choosing the earthquakes records with high ratio of signal-noise ,which were recorded at the stations from 1989 to 1999, we obtain the single trace Lg coda Q and its frequency dependent factor n. The results proved that SIS model is the reasonable model to explain the Lg coda wave, and SSR method also can be used to process Lg coda of regional earthquakes to get to the satisfied Lg coda Q. Based on the Lg coda Q we obtained using the former method, we explore the programs to inverse the regional Lg coda Q independently, and then make use of them to inverse the Lg coda Q of Beijing and adjacent area. The inversion result is satisfied. We conclude that the distribution of Qo (Q in lHz) is marked by the inhomogeneity, which is related to the tectonic structure: The value of Qo in uplift area, for example, Yanshan uplift, Taihang uplift, Luxi Uplift, is higher than the depression area, for example, Jizhong depression, Huanghua depression, and Jiyang depression, and the border between the higher Q area and lower Q area is very clear; Lg coda Q is also related to the velocity structure, higher velocity area is also with higher Q, lower velocity area is with lower Q; and higher heat-flow area is companied with lower Q. All in all, the value of Q reflects the difference of characteristics of lithofaces, porosity, the liquid content between the pores and heat flow. So, the Q value difference between uplift area and depression area reveals the difference of tectonic structure, lithology and physical character of the rock. So, the study of Lg coda Q is help to understand the earthquakes propagation mechanism through the inhomogenous medium, the cause of the coda, attenuation mechanism of the coda. Making use of the lateral images of Q, with velocity images, heat flow results, and other experimental result, we will be promoted to understand the complex structure of the crust, its inhomogenous character, and so on.

黄骅坳陷高尘头地区储层非均质性及成藏研究

Gaochentou region is located in the southwest direction of Gaochentou village in Huanghua city of Hebei province. In regionally structural position, It lies in Qikou sag In the middle part of Huanghua depression, which belongs to the east part of the south Dagang structure zone in the middle part of Huanghua depression. Its' very beneficial at regional structure in Gaochentou , and It becomes the advantage area for oil and gas gathered and preserved, Sandstone reservoir of Dongying Formation is main bearing bed .Dongying Formation in Gaochentou region of Huanghua depression is consisted of set of mudstone and sandstone interbeds by deposited delta fades . Dongying Formation can be divided into 3 members from above to below: the first member of Dongying Formation (FMDF), the second member of Dongying Formation (SMDF), and third member of Dongying Formation (TMDF). The lithology of the upper part of FMDF was consisted of mostly middle-grained and fine-grained sandstone, and it is small for the oil-bearing area of the sand bodies .The lithology of the lower part is coarse-grained sandstone bodies which are well connected between sandstone bodies of wells, and the lower part was main bed of oil production in Dongying Formation; SMDF and TMDF are consisted of larger scale set of mudstone, in which the sandbodies are lenticular and pinch out quickly, and the lithology was mostly fine sandstone and silt stone, in which there are little oil and gas .Because the reservoirs in this area are largely influenced by the factors such as lithology, fault and others, and the reservoirs have the strong,heterogeneity , there exists the problem of oil-down and water-up for vertical distribution of oil and gas bearing. It is not very clearly for the three dimension distribution of sandstone , and the geology researchs is not enough. So, it can't satisfy the need of further development and production for Gaochentou oilfield.Having the key problem of oil-down and water-up and the mechanism of the reservoir for Gaochentou area, There are as follow study works, the first, is study of the high-resolution correlation of sequence stratigraphy and sedimentary microfacies. Dongying Formation was divided into three parasequence sets and each parasequence set was divided into different amount of parasequences. FMDF, as the main oil and gas producing bed, can be divided into seven parasequences. Oil and gas are discovered in six parasequences except the seventh. On the basis of study of sedimentary microfacies, the sediments of Dongying Formation are considered deposited mainly in delta front subfacies. The microfacies types of Dongying Formation are sub-water distirbutary channel, sub-water natural bank, inter distributary channel bay, distributary channel mouth dam, and delta front mat sand.Seismic facies analysis and logging-constrained inversion technique were applied by Author for transverse prediction of sandstone reservoir. Having 4 modes of interwell single sandbodies correlation technique, Author have described distribution characteristics of sandbodies, and established geological reservoir model of Gaochentou reservoir.Author presented that the reservoirs characteristic have very strong heterogeneity ,and In the section of sandstone interlayed with mudstone,the folium sandstone interlayed with each other, and the wedge shaped sandbodies pinched out in the mudstone. So the pinch-out up sandstone trap and lenticular sandstone trap are easily formed. They are most small scale overlying pinches out in the place of slope. This article applies the concept of deep basin oil to resolve reasonably the problem of which the oil is below the water in Gaochentou area. Combined with the study of sedimentary facies, reservoir and other aspects, the mechanism and patterns of deep basin oil are studied on the basis of characteristics in Gaochentou area.On the basis of the above study, the mechanism of the oil and gas' migration and accumulation in isotropic sandstone and heterogeneous sandstone are thoroughly analyzed through experiments on physical modeling. Experiments on physical modeling show that the discrepancy between sand layers with different permeability and thickness has important influence on the direction, path, and injection layer of oil's migration. At the beginning of the injection of oil and gas in high permeability sand layer, the pressure is low, the migration resistance is small, and the oil and gas are more easily displacing the water in sand. So it can act as good transformation layer or reservoir. But at the beginning of the injection of oil and gas in sand layer with low permeability, the pressure is high, the migration resistance is big, and the oil and gas are more difficultly displacing the water in sand. So it can only act as bad or worse transformation layer or reservoir. Even if it cannot act as transformation layer or reservoir, it can act as water layer or dry layer. The discrepancy between sand layers on permeability and thickness can make discrepancy in injection of oil and gas between different layers. Consequently it leads to small amount of oil and gas injection in sand layers with low permeability. Ultimately it affects the oil's accumulation and distribution in different sand layers.At Last, combining analysis of the structure and pool forming condition, The thesis has established models of reservoir formation to predict the advantage distribution of oil and gas bearing , and put forward the prospective target It is not only of theoretical signification for explosion and importance, but also has realistic value in guiding the progressive petroleum exploration and exploitation.

地震反射界面形态与介质各向异性属性联立成像：地震反射波旅行时与偏振信息综合反演

It has been a difficult problem faced by seismologists for long time that how exactly to reconstruct the earth's geometric structure and distribution of physical attributes according to seismic wave's kinematical and dynamic characteristics, obtained in seismological observation. The jointing imaging of seismic reflector and anisotropy attributes in the earth interior is becoming the research hot spot. The limitation of shoot and observation system makes that the obtained seismic data are too scarce to exactly reconstruct the geological objects. It is popular that utilizing only seismic reflection traveltimes or polarizations information make inversion of the earth's velocity distribution by fixing seismic reflector configuration (vice versa), these will lead to the serious non-uniqueness reconstruction due to short of effective data, the non-uniqueness problem of reconstructing anisotropy attributes will be more serious than in isotropy media. Obviously it is not enough to restrict the media structure only by information of seismic reflection traveltimes or polarizations, which even sometimes will lead to distorted images and misinterpretation of subsurface structure. So we try to rebuild seismic reflection structure (geometry) and media anisotropic structure (physics) in the earth interior by jointing data of seismic wave kinematics and dynamics characteristics, we carry out the new experiment step by step, and the research mainly comprises of two parts: one is the reconstruction of P-wave vertical velocity and anisotropic structure(Thomsen parameter s and 8) in the transversely isotropic media with vertical symmetrical axis(VTI) by fixing geometrical structure, and the other is the simultaneous inversion of the reflector surface conformation and seismic anisotropic structure by jointing seismic reflection traveltimes and polarizations data. Simulated annealing method is used to the first research part, linear inversion based on BG theory and Simulated annealing are applied to the second one. All the research methods are checked by model experiments, then applied to the real data of the wide-angle seismic profile from Tunxi, Anhui Province, to Wenzhou, Zhejiang Province. The results are as following The inversion results based on jointing seismic PP-wave or PSV-wavereflection traveltimes and polarizations data are more close to real model than themodels based simply on one of the two data respectively. It is shown that the methodwe present here can effectively reconstruct the anisotropy attributes in the earth'sinterior when seismic reflector structure is fixed.The layer thickness, P-wave vertical velocity and Thomsen anisotropicparameters {s and 8) could be resolved simultaneously by jointing inversion ofseismic reflection traveltimes and polarizations with the linear inversion methodbased on BG theory.The image of the reflector structure, P-wave vertical velocity and theanisotropy parameters in the crust could be obtained from the wide-angle seismicprofile from Tunxi (in Anhui Province), to Wenzhou (in Zhejiang Province). Theresults reveal the difference of the reflector geometrical structure and physicalattributes in the crust between Yangtze block and Cathaysia block, and attempt tounderstand the characteristics of the crustal stress field in the areas.