971 resultados para Seedling limitation
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在网络遥操作中存在着由于操作者的操作负担过重或长时间操作而引起的误操作问题,提出以著名的BDIAgent模型为基础,通过引入中断机制,将反映操作者智能决策的操作目标、操作意图与BDIAgent推理产生的目标、意图进行结合的方法,为解决Agent智能的局限性和操作者的误操作问题,提供了一种人机接口方法,实现了人机智能结合.给出了中断的引入方法和操作者操作目标、操作意图中断响应原理,用形式化模型描述了人机智能决策选取目标和意图的过程.该人机智能结合方法在网络遥操作RoboCup中型足球机器人系统中得到了应用.
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本文针对多用户访问Web数据库的过程进行了分析并提出改进思路,然后利用带抑止弧的扩充Petri网对改进后的访问过程进行建模。
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针对柔性关节机械臂从自由空间运动控制过渡到约束空间力控制的过程中,存在冲击、震荡甚至不稳定等问题,利用加速度传感器反馈控制,为柔性关节机械臂的接触力控制在较宽的带宽内提供阻尼,克服了利用单纯速度反馈控制带宽窄的局限。对柔性关节机械臂的接触力控制进行建模和基于加速度反馈的控制策略分析,并在柔性关节机械臂上进行了接触力控制的试验研究。结果表明,这种方法有效。
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当今智能科学与智能技术是科技界的一个热点。在这方面有很多争议。有些学者怀疑智能技术前景,将现有“智能系统”与人相比,根本上否定有什么智能,认为只不过是一套专用软件。有的则过份乐观,我们认为过份悲观或过份乐观都是错误的,这里首先要区分智能科学与智能技术。前者是研究人所具有的自然现象,后者是开发一种技术去替代人的某些脑力劳动。其次,应正确认识现有智能技术方法的局限性。
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由于MCS-51系列微控制器存在着硬件堆栈小的结构缺陷,无法满足多任务环境下进行任务切换的需求,因此很难将uC/OS—II移植到MCS-51系列微控制器上。本文给出的"堆栈映射"方式很好的解决了这个问题。同时还对uC/OS—II移植过程中一些关键性问题给予了详细的论述。包括:uC/OS—II可移植的条件、内核配置和裁剪以及内核调试。
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With the development of oil/gas seismic exploration, seismic survey for fracture/porosity type reservoir is becoming more and more important. As for China, since it has over 60% store of low porosity and low permeability oil/gas reservoir, it’s more urgent to validly describe fracture/porosity type oil/gas trap and proposing the related, developed seismic technique. To achieve mapping fracture/porosity region and its development status, it demands profound understanding of seismic wave propagation discipline in complex fractured/pored media. Meanwhile, it has profound scientific significance and applied worth to study forward modeling of fracture/porosity type media and pre-stacked reverse time migration. Especially, pre-stacked reverse-time migration is the lead edge technique in the field of seismology and seismic exploration. In this paper, the author has summarized the meaning, history and the present state of numerical simulation of seismic propagation in fractured/pored media and seismic exploration of fractured/pored reservoirs. Extensive Dilatancy Anisotropy (EDA) model is selected as media object in this work. As to forward modeling, due to local limitation of solving spatial partial derivative when using finite-difference and finite-element method, the author turns to pseudo-spectral method (PSM), which is based on the global characteristic of Fourier transform to simulate three-component elastic wave-field. Artifact boundary effect reduction and simulation algorithm stability are also discussed in the work. The author has completed successfully forward modeling coding of elastic wave-field and numerical simulation of two-dimensional and three-dimensional EDA models with different symmetric axis. Seismic dynamic and kinematical properties of EDA media are analyzed from time slices and seismic records of wave propagation. As to pre-stacked reverse-time migration for elastic wave-field in fractured/pored media, based on the successful experience in forward modeling results with PSM, the author has studied pre-stacked reverse-time depth-domain migration technique using PSM of elastic wave-field in two dimensional EDA media induced by preferred fracture/pore distribution. At the same time, different image conditions will bring up what kind of migration result is detailed in this paper. The author has worded out software for pre-stacked reverse-time depth-domain migration of elastic wave-field in EDA media. After migration processing of a series of seismic shot gathers, influences to migration from different isotropic and anisotropy models are described in the paper. In summary, following creative research achievements are obtained: Realizing two-dimensional and three-dimensional elastic wave-field modeling for fractured/pored media and related software has been completed. Proposed pre-stacked reverse-time depth-domain migration technique using PSM of elastic wave-field. Through analysis of the seismic dynamic and kinematical properties of EDA media, the author made a conclusion that collection of multi-component seismic data can provide important data basis for locating and describing the fracture/pore regions and their magnitudes and the preferred directions. Pre-stacked reverse-time depth-domain migration technique has the ability to reconstruct complex geological object with steep formations and tilt fracture distribution. Neglecting seismic anisotropy induced by the preferred fracture/pore distribution, will lead to the disastrous imaging results.
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Dam is the key main works in the construction of water power. The success or failure of the construction of the dam mainly depends on the stability of the dam foundation. The double curvature arch dam-XiaoWan Dam is the highest one among the dams with the same type in the world, and the water thrust acted on it reaches ton, so the rock bearing capacity of dam foundation becomes more important. Because of the high and steep valley-side slope, the large scale of excavation and the complex body type of excavation, it is prominent that the problem of stress release of the rock mass in dam foundation. More great attentions should be paid for the stability and the degraded of rock properties of rock mass induced by the stress release. In this paper, the phenomena of stress release of rock mass in XiaoWan Dam foundation and its mechanisms were analyzed based on the collection of data, the detailed field engineering investigations, measurement of the rock mass and the 2D numerical calculations. The rock mass under the foundation is weak-weathered to intact, the quality of which is good. After excavation of the foundation, the rock mass near the slope surface occurred extend, stretch and stick-slip along original textures till the new fracture surface formed. Then platy structure of the rock mass takes on. The rock mass in the dam foundation occur resilience due to stress release towards free faces with the characteristics of time effect and localized deformation. In-situ measurements show that the rock mass near the surface are degraded. The stress release induced by excavation is a process of the interaction between engineering structures and geologic body. The stress release of rock mass in dam foundation is related to the changed degree of geometrical conditions. The rock near excavation surface failed nearly under uniaxial stresses. The bending-breaking mechanism of plate girder can interpret the failure model of the rock mass with platy structure in dam foundation slope. In essence, the stress release is the change of stress field including the change of directions and magnitudes of stress induced by excavation, which can induce the comedown of the safety margin. In this paper, the inducing conditions of stress release were calculated by numerical analyses. Moreover, from the point of view that the change of stress field, the coefficient of K, i.e. the variable load coefficient was proposed. Then the law of the change of it is interpreted. The distributional characteristics of fracture zone were expressed by the coefficient. The stress release of hard rock has the characteristic of localization. The measuring technique of sound wave can not reflect the small cracks in this kind of rock mass due to stress release. So, the spectral analysis method was proposed. At the same time, the application foreground in engineering of the Stockwell Time-Frequency- Spectrum method was discussed with a view to the limitation of it.
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Offshore seismic exploration is full of high investment and risk. And there are many problems, such as multiple. The technology of high resolution and high S/N ratio on marine seismic data processing is becoming an important project. In this paper, the technology of multi-scale decomposition on both prestack and poststack seismic data based on wavelet and Hilbert-Huang transform and the theory of phase deconvolution is proposed by analysis of marine seismic exploration, investigation and study of literatures, and integration of current mainstream and emerging technology. Related algorithms are studied. The Pyramid algorithm of decomposition and reconstruction had been given by the Mallat algorithm of discrete wavelet transform In this paper, it is introduced into seismic data processing, the validity is shown by test with field data. The main idea of Hilbert-Huang transform is the empirical mode decomposition with which any complicated data set can be decomposed into a finite and often small number of intrinsic mode functions that admit well-behaved Hilbert transform. After the decomposition, a analytical signal is constructed by Hilbert transform, from which the instantaneous frequency and amplitude can be obtained. And then, Hilbert spectrum. This decomposition method is adaptive and highly efficient. Since the decomposition is based on the local characteristics of the time scale of data, it is applicable to nonlinear and non-stationary processes. The phenomenons of fitting overshoot and undershoot and end swings are analyzed in Hilbert-Huang transform. And these phenomenons are eliminated by effective method which is studied in the paper. The technology of multi-scale decomposition on both prestack and poststack seismic data can realize the amplitude preserved processing, enhance the seismic data resolution greatly, and overcome the problem that different frequency components can not restore amplitude properly uniformly in the conventional method. The method of phase deconvolution, which has overcome the minimum phase limitation in traditional deconvolution, approached the base fact well that the seismic wavelet is phase mixed in practical application. And a more reliable result will be given by this method. In the applied research, the high resolution relative amplitude preserved processing result has been obtained by careful analysis and research with the application of the methods mentioned above in seismic data processing in four different target areas of China Sea. Finally, a set of processing flow and method system was formed in the paper, which has been carried on in the application in the actual production process and has made the good progress and the huge economic benefit.
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Landslide is a kind of serious geological hazards and its damage is very great. In recent years, landslides become more and more frequent along with increase of scale of engineering constructions and cause greater loss. Consequently, how to protect landslides has become important research subject in the engineering field. This paper improves the method how to compute landslide thrust and solves the irrational problem in the design of piles because of the irrational landslide thrust according to the theory and technology of existed anti-slide piles and pre-stressed cable anti-slide piles. Modern pre-stressing technology has been introduced and load balancing method has been used to improve the stressing behavior of anti-slide piles. Anchor cables, anti-slide piles and modern pre-stressing technology have been used to prevention complicated landslide. It is an important base to select values for the landslide thrust. An improved method to calculate design thrust of anti-slide piles has been presented in this paper on the base of residual thrust method by comparing existing methods to select values of landslide thrust in the design of anti-slide piles. In the method, residual landslide thrust behind the anti-slide piles and residual skid resistance before the piles has been analyzed, equitable distribution of residual landslide thrust behind the piles has been realized, and the method to select value of design thrust becomes more reasonable. The pre-stressed cable anti-slide piles are developed from the common anti-slide piles and are common method to prevent landslide. Their principle is that internal force of anti-slide piles is adjusted and size of section is diminished by changing constraint conditions of anti-slide piles. For landslides with deep slip surface and large scale of slopes, limitation of the method appears. Such landslides are in need of long piles and anchor cables which are not only non-economic but also can generate larger deformation and leave potential danger after prevention. For solving the problem, a new kind of anti-slide piles, inner pre-stressing force anti-slide piles, is presented in this paper, and its principle is that an additional force, which is generated in the inner anti-slide piles by arranging pre-stressed reinforcement or tight wire in a certain form in interior of anti-slide piles and stretching the steel reinforcement or tight wire, may balance out the internal force induced by landslide thrust whole or partly (load balancing method). The method will change bending moment which anti-slide piles are not good at bearing into compressive stress which piles are good at bearing, improve stressing performance of anti-slide piles greatly, diminish size of section, and make anti-slide piles not fissured in the natural service or postpone appearance of the fissures, and improve viability of anti-slide piles. Pre-stressed cable anti-slide piles and inner pre-stressing force anti-slide piles go by the general name of pre-stressed structure anti-slide piles in the paper, and their design and calculation method is also analyzed. A new calculation method is provided in the paper for design of anti-slide piles. For pre-stressed structure anti-slide piles, a new computation mode is firstly presented in the paper on the foundation of cantilever piles. In the mode, constraint form of load-bearing section of the anti-slide piles should be confirmed according to reservoir conditions in order to figure out amount of pre-stress of the anchor cables, and internal force should be analyzed for the load-bearing section of pre-stressed structure anti-slide piles so as to confirm anchorage section of anti-slide piles. Pre-stressed cables of the pre-stressed cable anti-slide piles can be arranged as required. This paper analyzes the load-bearing section of single-row and double-row pre-stressed cable anti-slide piles and provides a calculation method for design of the pre-stressed cable anti-slide piles. Inner pre-stressing force anti-slide piles are a new kind of structural style. Their load-bearing section is divided into four computation modes according to whether pre-stressed cables are applied for exterior of the anti-slide piles, and whether single-row or double-row exterior pre-stressed cables are applied. The load balancing method is used to analyze the computation modes for providing a method to design the inner pre-stressing force anti-slide piles rationally. Pre-stressed cable anti-slide piles and inner pre-stressing force anti-slide piles are applied to research on Mahe landfall in Yalong Lenggu hydropower station by the improved method to select value of design thrust of anti-slide piles. A good effect is obtained in the analysis.
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There has been a growing concern about the use of fossil fuels and its adverse effects on the atmospheric greenhouse and ecological environment. A reduction in the release rate of CO2 into the atmosphere poses a major challenge to the land ecology of China. The most promising way of achieving CO2 reduction is to dispose of CO2 in deep saline aquifers. Deep aquifers have a large potential for CO2 sequestration in geological medium in terms of volume and duration. Through the numerical simulation of multiphase flow in a porous media, the transformation and motion of CO2 in saline aquifers has been implemented under various temperature and hydrostatic pressure conditions, which plays an important role to the assessment of the reliability and safety of CO2 geological storage. As expected, the calculated results can provide meaningful and scientific information for management purposes. The key problem to the numerical simulation of multiphase flow in a porous media is to accurately capture the mass interface and to deal with the geological heterogeneity. In this study, the updated CE/SE (Space and time conservation element and solution element) method has been proposed, and the Hybrid Particle Level Set method (HPLS) has extended for multiphase flows in porous medium, which can accurately trace the transformation of the mass interface. The benchmark problems have been applied to evaluate and validate the proposed method. In this study, the reliability of CO2 storage in saline aquifers in Daqingzi oil field in Sunlong basin has been discussed. The simulation code developed in this study takes into account the state for CO2 covering the triple point temperature and pressure to the supercritical region. The geological heterogeneity has been implemented, using the well known geostatistical model (GSLIB) on the base of the hard data. The 2D and 3D model have been set up to simulate the CO2 multiphase flow in the porous saline aquifer, applying the CE/SE method and the HPLS method .The main contents and results are summarized as followings. (1) The 2D CE/SE method with first and second –order accuracy has been extended to simulate the multiphase flow in porous medium, which takes into account the contribution of source and sink in the momentum equation. The 3D CE/SE method with the first accuracy has been deduced. The accuracy and efficiency of the proposed CE/SE method have been investigated, using the benchmark problems. (2) The hybrid particle level set method has been made appropriate and extended for capturing the mass interface of multiphase flows in porous media, and the numerical method for level set function calculated has been formulated. (3) The closed equations for multiphase flow in porous medium has been developed, adept to both the Darcy flow and non-Darcy flow, getting over the limitation of Reynolds number to the calculation. It is found that Darcy number has a decisive influence on pressure as well as velocity given the Darcy number. (4) The new Euler scheme for numerical simulations of multiphase flows in porous medium has been proposed, which is efficient and can accurately capture the mass interface. The artificial compressibility method has been used to couple the velocities and pressure. It is found that the Darcy number has determinant effects on the numerical convergence and stability. In terms of the different Darcy numbers, the coefficient of artificial compressibility and the time step have been obtained. (5) The time scale of the critical instability for critical CO2 in the saline aquifer has been found, which is comparable with that of completely CO2 dissolved saline aquifer. (6) The concept model for CO2 multiphase flows in the saline aquifer has been configured, based on the temperature, pressure, porosity as well as permeability of the field site .Numerical simulation of CO2 hydrodynamic trapping in saline aquifers has been performed, applying the proposed CE/SE method. The state for CO2 has been employed to take into account realistic reservoir conditions for CO2 geological sequestration. The geological heterogeneity has been sufficiently treated , using the geostatistical model. (7) It is found that the Rayleigh-Taylor instability phenomenon, which is associated with the penetration of saline fluid into CO2 fluid in the direction of gravity, has been observed in CO2 multiphase flows in the saline aquifer. Development of a mushroom-type spike is a strong indication of the formation of Kelvin-Helmholtz instability due to the developed short wavelength perturbations present along the interface and parallel to the bulk flow. Additional key findings: the geological heterogeneity can distort the flow convection. The ascending of CO2 can induce the persistent flow cycling effects. The results show that boundary conditions of the field site have determinant effects on the transformation and motion of CO2 in saline aquifers. It is confirmed that the proposed method and numerical model has the reliability to simulate the process of the hydrodynamic trapping, which is the controlling mechanism for the initial period of CO2 storage at time scale of 100 years.
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In modem signal Processing,non-linear,non-Gaussian and non-stable signals are usually the analyzed and Processed objects,especially non-stable signals. The convention always to analyze and Process non-stable signals are: short time Fourier transform,Wigner-Ville distribution,wavelet Transform and so on. But the above three algorithms are all based on Fourier Transform,so they all have the shortcoming of Fourier Analysis and cannot get rid of the localization of it. Hilbert-Huang Transform is a new non-stable signal processing technology,proposed by N. E. Huang in 1998. It is composed of Empirical Mode Decomposition (referred to as EMD) and Hilbert Spectral Analysis (referred to as HSA). After EMD Processing,any non-stable signal will be decomposed to a series of data sequences with different scales. Each sequence is called an Intrinsic Mode Function (referred to as IMF). And then the energy distribution plots of the original non-stable signal can be found by summing all the Hilbert spectrums of each IMF. In essence,this algorithm makes the non-stable signals become stable and decomposes the fluctuations and tendencies of different scales by degrees and at last describes the frequency components with instantaneous frequency and energy instead of the total frequency and energy in Fourier Spectral Analysis. In this case,the shortcoming of using many fake harmonic waves to describe non-linear and non-stable signals in Fourier Transform can be avoided. This Paper researches in the following parts: Firstly,This paper introduce the history and development of HHT,subsequently the characters and main issues of HHT. This paper briefly introduced the basic realization principles and algorithms of Hilbert-Huang transformation and confirms its validity by simulations. Secondly, This paper discuss on some shortcoming of HHT. By using FFT interpolation, we solve the problem of IMF instability and instantaneous frequency undulate which are caused by the insufficiency of sampling rate. As to the bound effect caused by the limitation of envelop algorithm of HHT, we use the wave characteristic matching method, and have good result. Thirdly, This paper do some deeply research on the application of HHT in electromagnetism signals processing. Based on the analysis of actual data examples, we discussed its application in electromagnetism signals processing and noise suppression. Using empirical mode decomposition method and multi-scale filter characteristics can effectively analyze the noise distribution of electromagnetism signal and suppress interference processing and information interpretability. It has been founded that selecting electromagnetism signal sessions using Hilbert time-frequency energy spectrum is helpful to improve signal quality and enhance the quality of data.
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Rock mass is widely recognized as a kind of geologic body which consists of rock blocks and discontinuities. The deformation and failure of rock mass is not only determined by rock block,but also by discontinuity which is virtually more important. Mutual cutting and combination of discontinuities controlled mechanical property of rock mass. The complex cutting of discontinuities determine the intense anisotropy on mechanical property of rock mass,especially under the effect of ground stress. Engineering practice has show that the brittle failure of hard rock always occurs when its working stress is far lower than the yield strength and compressive strength,the failure always directly related to the fracture propagation of discontinuities. Fracture propagation of discontinuities is the virtue of hard rock’s failure. We can research the rock mass discontinuous mechanical properties precisely by the methods of statistical analysis of discontinuities and Fracture Mechanics. According to Superposition Principle in Fracture Mechanics,A Problem or C Problem could be chosen to research. Problem A mainly calculates the crack-tip stress field and displacement field on internal discontinuities by numerical method. Problem C calculate the crack-tip stress field and displacement field under the assumption of that the mainly rock mass stress field has been known. So the Problem C avoid the complex mutual interference of stress fields of discontinuities,which is called crack system problem in Fracture Mechanics. To solve Problem C, field test on stress field in the rock mass is needed. The linear Superposition of discontinuities strain energies are Scientific and Rational. The difference of Fracture Mechanics between rock mass and other materials can mostly expression as:other materials Fracture Mechanics mostly face the problem A,and can’t avoid multi-crack puzzle, while the Rock mass Fracture Mechanics answer to the Problem C. Problem C can avoid multi-discontinuities mutual interference puzzle via the ground stress test. On the basis of Problem C, Fracture Mechanics could be used conveniently in rock mass. The rock mass statistics fracture constitutive relations, which introduced in this article, are based on the Problem C and the Discontinuity Strain Energy linear superposition. This constitutive relation has several merits: first, it is physical constitutive relation rather than empirical; second, it is very fit to describe the rock mass anisotropy properties; third, it elaborates the exogenous factors such as ground stress. The rock mass statistics fracture constitutive relation is the available approach to answer to the physical, anisotropic and ground stress impacted rock mass problems. This article stand on the foundation of predecessor’s statistics fractures constitutive relation, and improved the discontinuity distributive function. This article had derived the limitation of negative exponential distribution in the course of regression analysis, and advocated to using the two parameter negative exponential distribution for instead. In order to solve the problems of two-dimension stability on engineering key cross-sectional view in rock mass, this article derived the rock mass planar flexibility tensor, and established rock mass two-dimension penetrate statistics fracture constitutive relation on the basis of penetrate fracture mechanics. Based on the crack tip plasticity research production of penetrate fracture, for example the Irwin plasticity equifinality crack, this article established the way to deal with the discontinuity stress singularity and plastic yielding problem at discontinuity tip. The research on deformation parameters is always the high light region of rock mass mechanics field. After the dam foundation excavation of XiaoWan hydroelectric power station, dam foundation rock mass upgrowthed a great deal of unload cracks, rock mass mechanical property gotten intricacy and strong anisotropy. The dam foundation rock mass mostly upgrowthed three group discontinuities: the decantation discontinuity, the steep pitch discontinuity, and the schistosity plane. Most of the discontinuities have got partial unload looseness. In accordance with ground stress field data, the dam foundation stress field greatly non-uniform, which felled under the great impaction of tectonic stress field, self-weight stress field, excavation geometric boundary condition, and excavation, unload. The discontinuity complexity and stress field heterogeneity, created the rock mass mechanical property of dam foundation intricacy and levity. The research on the rock mass mechanics, if not take every respected influencing factor into consideration as best as we can, major errors likely to be created. This article calculated the rock mass elastic modulus that after Xiao Wan hydroelectric power station dam foundation gutter excavation finished. The calculation region covered possession monolith of Xiao Wan concrete double-curvature arch dam. Different monolith were adopted the penetrate fracture statistics constitutive relation or bury fracture statistics constitutive relation selectively. Statistics fracture constitutive relation is fit for the intensity anisotropy and heterogeneity rock mass of Xiao Wan hydroelectric power station dam foundation. This article had contrastive analysis the statistics fracture constitutive relation result with the inclined plane load test actual measurement elastic modulus and RMR method estimated elastic modulus, and find that the three methods elastic modulus have got greatly comparability. So, the statistics fracture constitutive relations are qualified for trust. Generally speaking,this article had finished following works based on predecessors job: “Argumentation the C Problems of superposition principle in Fracture Mechanics, establish two-dimension penetrate statistics fracture constitutive relation of rock mass, argue the negative exponential distribution limitation and improve it, improve of the three-dimension berry statistics fracture constitutive relation of rock mass, discontinuity-tip plastic zone isoeffect calculation, calculate the rock mass elastic modulus on two-dimension cross-sectional view”. The whole research clue of this article inherited from the “statistics rock mass mechanics” of Wu Faquan(1992).
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Halfgraben-like depressions have multiple layers of subtle traps, multiple coverings of oil-bearing series and multiple types of reservoirs. But these reservoirs have features of strong concealment and are difficult to explore. For this reason, many scholars contribute efforts to study the pool-forming mechanism for this kind of basins, and establish the basis for reservoir exploration and development. However, further study is needed. This paper takes HuiMin depression as an example to study the pool-forming model for the gentle slope belts of fault-depression lake basins. Applying multi-discipline theory, methods and technologies including sedimentary geology, structural geology, log geology, seismic geology, rock mechanics and fluid mechanics, and furthermore applying the dynamo-static data of oil reservoir and computer means in maximum limitation, this paper, qualitatively and quantitatively studies the depositional system, structural framework, structural evolution, structural lithofacies and tectonic stress field, as well as fluid potential field, sealing and opening properties of controlling-oil faults and reservoir prediction, finally presents a pool-forming model, and develops a series of methods and technologies suited to the reservoir prediction of the gentle slope belt. The results obtained in this paper richen the pool-forming theory of a complex oil-gas accumulative area in the gentle slope belt of a continental fault-depression basin. The research work begins with the study of geometric shape of fracture system, then the structural form, activity stages and time-space juxtaposition of faults with different level and different quality are investigated. On the basis of study of the burial history, subsidence history and structural evolution history, this paper synthesizes the studied results of deposition system, analyses the structural lithofacies of the gentle slope belt in the HuiMing Depression and its controlling roles to oil reservoir in the different structural lithofacies belts in time-space, and presents their evolution patterns. The study of structural stress field and fluid potential field indicates that the stress field has a great change from the Dong Ying stages to nowadays. One marked point among them is that the Dong Ying double peak- shaped nose structures usually were the favorable directional area for oil and gas migration, while the QuDi horst became favorable directional area since the GuanTao stage. Based on the active regular of fractures and the information of crude oil saturation pressure, this paper firstly demonstrates that the pool-forming stages of the LingNan field were prior to the stages of the QuDi field, whici provides new eyereach and thinking for hydrocarbon exploration in the gentle slope belt. The BeiQiao-RenFeng buried hill belt is a high value area with the maximum stress values from beginning to end, thus it is a favorable directional area for oil and gas migration. The opening and sealing properties of fractures are studied. The results obtained demonstrate their difference in the hydrocarbon pool formation. The seal abilities relate not only with the quality, direction and scale of normal stress, with the interface between the rocks of two sides of a fault and with the shale smear factor (SSF), but they relate also with the juxtaposition of fault motion stage and hydrocarbon migration. In the HuiMin gentle slope belt, the fault seal has difference both in different stages, and in different location and depth in the same stage. The seal extent also displays much difference. Therefore, the fault seal has time-space difference. On the basis of study of fault seal history, together with the obtained achievement of structural stress field and fluid potential field, it is discovered that for the pool-forming process of oil and gas in the studied area the fault seal of nowadays is better than that of the Ed and Ng stages, it plays an important role to determine the oil column height and hydrocarbon preservation. However, the fault seal of the Ed and Ng stages has an important influence for the distribution state of oil and gas. Because the influential parameters are complicated and undefined, we adopt SSF in the research work. It well reflects synthetic effect of each parameter which influences fault seal. On the basis of the above studies, three systems of hydrocarbon migration and accumulation, as well as a pool-forming model are established for the gentle slope belt of the HuiMin depression, which can be applied for the prediction of regular patterns of oil-gas migration. Under guidance of the pool-forming geological model for the HuiMin slope belt, and taking seismic facies technology, log constraint evolution technology, pattern recognition of multiple parameter reservoir and discrimination technology of oil-bearing ability, this paper develops a set of methods and technologies suited to oil reservoir prediction of the gentle slope belt. Good economic benefit has been obtained.
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Cross well seismic technique is a new type of geophysical method, which observes the seismic wave of the geologic body by placing both the source and receiver in the wells. By applying this method, it averted the absorption to high-frequency component of seismic signal caused by low weathering layers, thus, an extremely high-resolution seismic signal can be acquired. And extremely fine image of cross well formations, structure, and reservoir can be achieved as well. An integrated research is conducted to the high-frequency S-wave and P-wave data and some other data to determine the small faults, small structure and resolving the issues concerning the thin bed and reservoir's connectivity, fluid distribution, steam injection and fracture. This method connects the high-resolution surface seismic, logging and reservoir engineering. In this paper, based on the E & P situation in the oilfield and the theory of geophysical exploration, a research is conducted on cross well seismic technology in general and its important issues in cross well seismic technology in particular. A technological series of integrated field acquisition, data processing and interpretation and its integrated application research were developed and this new method can be applied to oilfield development and optimizing oilfield development scheme. The contents and results in this paper are as listed follows: An overview was given on the status quo and development of the cross well seismic method and problems concerning the cross well seismic technology and the difference in cross well seismic technology between China and international levels; And an analysis and comparison are given on foreign-made field data acquisition systems for cross-well seismic and pointed out the pros and cons of the field systems manufactured by these two foreign companies and this is highly valuable to import foreign-made cross well seismic field acquisition system for China. After analyses were conducted to the geometry design and field data for the cross well seismic method, a common wave field time-depth curve equation was derived and three types of pipe waves were discovered for the first time. Then, a research was conducted on the mechanism for its generation. Based on the wave field separation theory for cross well seismic method, we believe that different type of wave fields in different gather domain has different attributes characteristics, multiple methods (for instance, F-K filtering and median filtering) were applied in eliminating and suppressing the cross well disturbances and successfully separated the upgoing and downgoing waves and a satisfactory result has been achieved. In the area of wave field numerical simulation for cross well seismic method, a analysis was conducted on conventional ray tracing method and its shortcomings and proposed a minimum travel time ray tracing method based on Feraiat theory in this paper. This method is not only has high-speed calculation, but also with no rays enter into "dead end" or "blinded spot" after numerous iterations and it is become more adequate for complex velocity model. This is first time that the travel time interpolation has been brought into consideration, a dynamic ray tracing method with shortest possible path has been developed for the first arrivals of any complex mediums, such as transmission, diffraction and refraction, etc and eliminated the limitation for only traveling from one node to another node and increases the calculation accuracy for minimum travel time and ray tracing path and derives solution and corresponding edge conditions to the fourth-order differential sonic wave equation. The final step is to calculate cross well seismic synthetics for given source and receivers from multiple geological bodies. Thus, real cross-well seismic wave field can be recognized through scientific means and provides important foundation to guide the cross well seismic field geometry designing. A velocity tomographic inversion of the least square conjugated gradient method was developed for cross well seismic velocity tomopgraphic inversion and a modification has been made to object function of the old high frequency ray tracing method and put forward a thin bed oriented model for finite frequency velocity tomographic inversion method. As the theory model and results demonstrates that the method is simple and effective and is very important in seismic ray tomographic imaging for the complex geological body. Based on the characteristics of the cross well seismic algorithm, a processing flow for cross well seismic data processing has been built and optimized and applied to the production, a good section of velocity tomopgrphic inversion and cross well reflection imaging has been acquired. The cross well seismic data is acquired from the depth domain and how to interprets the depth domain data and retrieve the attributes is a brand new subject. After research was conducted on synthetics and trace integration from depth domain for the cross well seismic data interpretation, first of all, a research was conducted on logging constraint wave impedance of cross well seismic data and initially set up cross well seismic data interpretation flows. After it applied and interpreted to the cross well seismic data and a good geological results has been achieved in velocity tomographic inversion and reflection depth imaging and a lot of difficult problems for oilfield development has been resolved. This powerful, new method is good for oilfield development scheme optimization and increasing EOR. Based on conventional reservoir geological model building from logging data, a new method is also discussed on constraining the accuracy of reservoir geological model by applying the high resolution cross well seismic data and it has applied to Fan 124 project and a good results has been achieved which it presents a bight future for the cross well seismic technology.
Resumo:
Formation resistivity is one of the most important parameters to be evaluated in the evaluation of reservoir. In order to acquire the true value of virginal formation, various types of resistivity logging tools have been developed. However, with the increment of the proved reserves, the thickness of interest pay zone is becoming thinner and thinner, especially in the terrestrial deposit oilfield, so that electrical logging tools, limited by the contradictory requirements of resolution and investigation depth of this kinds of tools, can not provide the true value of the formation resistivity. Therefore, resitivity inversion techniques have been popular in the determination of true formation resistivity based on the improving logging data from new tools. In geophysical inverse problems, non-unique solution is inevitable due to the noisy data and deficient measurement information. I address this problem in my dissertation from three aspects, data acquisition, data processing/inversion and applications of the results/ uncertainty evaluation of the non-unique solution. Some other problems in the traditional inversion methods such as slowness speed of the convergence and the initial-correlation results. Firstly, I deal with the uncertainties in the data to be processed. The combination of micro-spherically focused log (MSFL) and dual laterolog(DLL) is the standard program to determine formation resistivity. During the inversion, the readings of MSFL are regarded as the resistivity of invasion zone of the formation after being corrected. However, the errors can be as large as 30 percent due to mud cake influence even if the rugose borehole effects on the readings of MSFL can be ignored. Furthermore, there still are argues about whether the two logs can be quantitatively used to determine formation resisitivities due to the different measurement principles. Thus, anew type of laterolog tool is designed theoretically. The new tool can provide three curves with different investigation depths and the nearly same resolution. The resolution is about 0.4meter. Secondly, because the popular iterative inversion method based on the least-square estimation can not solve problems more than two parameters simultaneously and the new laterolog logging tool is not applied to practice, my work is focused on two parameters inversion (radius of the invasion and the resistivty of virgin information ) of traditional dual laterolog logging data. An unequal weighted damp factors- revised method is developed to instead of the parameter-revised techniques used in the traditional inversion method. In this new method, the parameter is revised not only dependency on the damp its self but also dependency on the difference between the measurement data and the fitting data in different layers. At least 2 iterative numbers are reduced than the older method, the computation cost of inversion is reduced. The damp least-squares inversion method is the realization of Tikhonov's tradeoff theory on the smooth solution and stability of inversion process. This method is realized through linearity of non-linear inversion problem which must lead to the dependency of solution on the initial value of parameters. Thus, severe debates on efficiency of this kinds of methods are getting popular with the developments of non-linear processing methods. The artificial neural net method is proposed in this dissertation. The database of tool's response to formation parameters is built through the modeling of the laterolog tool and then is used to training the neural nets. A unit model is put forward to simplify the dada space and an additional physical limitation is applied to optimize the net after the cross-validation method is done. Results show that the neural net inversion method could replace the traditional inversion method in a single formation and can be used a method to determine the initial value of the traditional method. No matter what method is developed, the non-uniqueness and uncertainties of the solution could be inevitable. Thus, it is wise to evaluate the non-uniqueness and uncertainties of the solution in the application of inversion results. Bayes theorem provides a way to solve such problems. This method is illustrately discussed in a single formation and achieve plausible results. In the end, the traditional least squares inversion method is used to process raw logging data, the calculated oil saturation increased 20 percent than that not be proceed compared to core analysis.