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1.
随着油气勘探难度不断增加,叠前弹性参数反演在油气勘探领域已逐渐成为一种有效的储层预测方法.该方法以Zoeppritz方程为基础,相较于叠后反演,叠前数据保留了大量与炮检距相关信息,在精度上有了较大的提升.本文从叠前AVO反演出发,利用纵横波联合反演方法对纵横波速度与密度三参数进行反演,并在模型和工区进行测试及应用.再利用弹性参数对岩石以及岩石填充物的不同敏感性进行储层预测.结果表明,叠前反演分辨率高,对储层的刻画明晰,且反演结果与井吻合度高.将纵横波速度的低速区与低密度区结合分析来预测有利储层的位置,并用实际测井资料进行验证,证明了该方法在储层预测中的有效性和稳定性.  相似文献   

2.
地震成藏学是继地震地层学、地震沉积学和油气成藏学之后的一门新兴边缘交叉学科分支,是地球物理勘探技术及其成果与现代油气成藏理论相结合的产物.通过对其研究方法、内容及关键技术分析,认为直接利用地震解释成果(构造解释剖面、岩性反演剖面、烃检测剖面等)进行油气成藏分析是其研究的独特方法,它以精细地震构造解释技术、高精度地震岩性反演技术和稳定的地震弹性参数反演及烃类检测技术为手段,以现代油气成藏理论为指导,结合地震资料及解释成果,在油气潜力预测和勘探开发方面展示出良好的应用前景.以塔南凹陷t46井区为例,发现日产近万方的油气井,论证了高精度地震岩性反演技术在隐蔽油气藏(主要是岩性油气藏)预测中的重要价值.  相似文献   

3.
位场方法在非常规油气勘探中的应用   总被引:1,自引:0,他引:1  
在常规油气勘探领域,高精度的重磁资料能够非常好的完成油气资源的远景评价,为地震勘探和钻井提供指导.在非常规油气勘探领域,重磁勘探方法显得尤为重要.因为非常规油气资源的地质结构、圈闭条件、储层评价、成藏机理、渗流特征等方面更加复杂和未知,地震勘探和钻井难以直接开展,亟需非地震方法的优选规划.由于重磁位场方法并不能"特异性"的揭示地下页岩分布和页岩气的资源潜力,从某种程度上说,重磁位场方法在常规油气和非常规油气的勘探技术是没有多大区分的,核心都是"综合"二字.其中,对重磁资料的处理要经过常规的延拓、剩余重力异常提取和磁异常化极等,以及重力异常剥皮、park反演、梯度反演等关键处理,能够获取特定地层的厚度与埋深和断裂信息.本文以页岩气资源的重磁位场勘探技术为中心,通过调研国内外重磁方法在非常规油气勘探阶段的应用实例,总结规律,构建利用位场方法开展页岩气等资源勘探的技术体系与流程.  相似文献   

4.
致密砂岩油气藏在当前油气勘探开中占有重要地位.地震地质综合研究是此类油气藏勘探开发工作的重要组成部分.多数致密砂岩油气藏地表条件复杂,导致地震资料品质较差.油气藏岩性致密、低孔、低渗的地质特征导致地球物理异常微弱.这两个不利条件给地震地质综合研究造成了较大的困难.结合致密砂岩油气藏地震地质研究工作实践,本文对地震资料特殊处理、储层和特殊地质体地震预测与描述的关键技术进展及应用效果进行了阐述.面对黄土塬、山地等复杂地表采集条件和致密砂岩储层等特殊地质体地震地质研究的需要,介绍了高精度静校正、叠前多域去噪、地表一致性振幅补偿、小波变换提高分辨率处理技术及在鄂尔多斯盆地一些探区的应用情况.围绕致密储层等特殊地质体的地震预测与描述需求,着重介绍了致密砂泥岩地层岩石物理分析、煤系等特殊地层的地震属性分析与优化、致密碎屑岩储层反演、叠前地震资料流体检测、致密储层裂缝发育带地震预测和储层综合建模等关键技术在部尔多斯及川西探区实际应用中面临的具体问题、改进对策和实施效果.  相似文献   

5.
波阻抗反演在储层预测研究中的应用   总被引:3,自引:3,他引:0       下载免费PDF全文
随着勘探开发的不断深入, 对油气田的老区勘探开发及二次评价,在储层预测研究上,如何更有效地识别碎屑岩储层及变质岩储层,最大限度地降低波阻抗反演过程中某些不确定性因素造成的影响,以确保储层预测的精度,提高钻探的成功率. 波阻抗反演在以上两种储层反演预测的过程中,能够充分利用钻井、测井、试油、试采等动态、静态资料,更好的对地下地质体进行高精度反演预测,找出油气藏储层在纵向、横向上的分布规律,为井位部署及储量上报提供可靠的依据.  相似文献   

6.
塔里木盆地卡4区块AVO研究   总被引:3,自引:8,他引:3       下载免费PDF全文
塔里木盆地江汉探区卡塔克4区块位于塔里木盆地中部,有效面积为2 330 km2.在古城墟鼻状隆起构造背景上.该区块奥陶系鹰山组有气层显示(经古隆1井证实),为了弄清奥陶系内幕鹰山组储层分布,寻找有利区块,围绕卡4区块古城墟鼻隆的下步勘探部署开展了AVO处理.卡4区块奥陶系地层埋藏深(达6 000多米),目的层地震资料品质较差,唯一达到目的层的古隆1井属低产气井(日产气10 067 m3),低孔低渗的储层给叠前反演带来了很大困难.本文从AVO技术入手,通过不断深入的研究探讨,展开了储层预测技术攻关研究,为该区储层预测和含油气判别提供了有力依据.  相似文献   

7.
碳酸盐岩储层是南堡凹陷潜山重要的勘探领域,由于受到构造、岩性等多种因素的影响,常规储层预测难度大.本文提出相控储层预测方法,通过井上精细对比,确定南堡凹陷潜山碳酸盐岩储层的优势发育段,结合古地貌确定其有利分布相带,在有利相带约束下,优选出地震平均能量属性、曲率体属性、蚂蚁体属性和谱分解属性,融合这些属性,综合预测储层发育区.通过与已钻井的对比,储层发育区与钻井资料吻合度高,证实了该方法的有效性,同时为南堡凹陷潜山的展开勘探提供了参考.  相似文献   

8.
叠前同时反演在砂岩油藏预测中的应用   总被引:2,自引:0,他引:2  
AVO技术已成为非常重要的烃类检测的工具,而以AVO理论为基础的叠前同时反演则日益成为常用的研究方法.本文首先从已钻井岩石物理分析入手,综合已钻井的AVO正演模拟和流体替代,分析了利用AVO技术对研究区目标层进行岩性和油水识别的可行性.利用叠前同时反演得到了纵波阻抗、横波阻抗和密度数据体,在此基础上计算得到纵横波速度比和泊松阻抗数据体,对研究区目标层进行了岩性和油气预测,取得了良好的应用效果.  相似文献   

9.
在超高温高压环境下的深海钻井过程中,受关键层位、尤其是薄弱层(弱抗张力地层)影响,加上缺乏海上超高温高压薄弱层精准快速识别及关键层位精准卡层技术方法,以致钻井事故频发,是海上超高温高压油气勘探开发亟待解决的重要问题.随钻过程中高精度地震数据的应用,作为钻井过程实时监测的手段,能够有效提供钻头前方精细地质构造信息.本文在谱反演提高分辨率技术基础上,提出了基于压缩感知L0范数算法的谱反演算法,并形成完整的提高分辨率技术流程.该方法能够相对保幅保真地实现地震数据的有效拓频,识别薄弱层及实现随钻地震高精度关键层位综合预测.方法在南海西部油田深层的随钻实际数据分析中,有效识别了钻头前方薄弱层、关键地层、储层深度等关键信息,结果与钻后测井资料吻合,验证了方法有效性,为南海西部油田超高温高压钻井的风险评估提供依据.  相似文献   

10.
裂缝型碳酸盐岩储层由于极高的孔渗性,是最为有利的油气勘探目标之一.这类储层预测难度较大,特别是对于石膏和盐层非常发育的碳酸盐岩储层.本次研究从裂缝型碳酸盐岩的发育特征研究入手,分析地震识别此类储层的可行性.优选多种地震地质储层预测方法,针对土库曼斯坦阿姆河右岸区块霍贾姆巴兹三维区的储层特点,开展了一系列的含气储层预测研究.主要应用了相干分析,像素成像技术,叠前各向异性裂缝检测,构造应力场分析,蚂蚁追踪算法等技术.预测了研究区有利的含气储层发育带,预测储层与钻探结果符合程度较高.形成了裂缝型碳酸盐岩储层预测技术系列,在海外气田勘探实践中发挥了重要的作用.  相似文献   

11.
The data on geomagnetic reversals are compared with the changes in the organic world and with the lower-mantle plumes. The times of the formation of plumes and the times of their appearance on the Earth’s surface relate to the intervals characterized by the different frequencies of geomagnetic reversals, i.e., there is no interrelation between the formation of plumes and the frequency of the changes in the geomagnetic field polarity. At the same time, a certain synchronism is observed between the frequency of the geomagnetic reversals and the boundaries of the biostratigraphic ages, i.e., the changes in the organic world in the long-period range. A hypothesis is proposed, which explains the change in the sign of the geomagnetic field by the combined effect of the irregular rotation of the internal core relative to the mantle and the changes in the slope angle of the axis of the Earth’s rotation, which, in turn, results in synchronous events on the Earth’s surface: the rates of changes in the organic world.  相似文献   

12.
The developed dynamic model of the main geomagnetic field (MGF) includes the sources of three levels, which have existed and continuously changed during the 100-year period. The spatial-temporal dynamics of the secular variations in MGF has been considered based on this model. It has been indicated that, at different times, the formation of anomalies (located in similar regions) depended on the total dynamics of different combinations of sources, including a change in the parameters of the dipoles of the secondorder smallness. Anomalies generated by the dynamics of the dipoles of the third-order smallness do not evidently manifest themselves in the total secular variations but are responsible for the specific shapes of isodynamic lines. Based on the stability and continuity of the constructed model, the conclusion is made that long-living turbulent flows of different scales can exist in the liquid core.  相似文献   

13.
The results of the magnetotelluric (MT) soundings before and after an earthquake are analyzed. The interpretation is based on the longitudinal and transverse MT curves (along and across the strike of the main tectonic elements, respectively). The MT curves are distorted by the ρ- and coast effect. The distortions due to the coast effect are estimated by the testing three-dimensional (3D) model. It is established that the coast effect distortion at the periods up to 1000 s is small and can be disregarded. The divergence of the longitudinal and transverse MT curves, which points to the presence of the deep faults, is thoroughly studied. The inversion of the MTsounding curves is carried out by the REBOCC program of the numerical two-dimensional modeling. This program implements the procedures of elimination of the ρ-effect and the joint inversion of the longitudinal and transverse MT sounding curves. The obtained geoelectrical cross sections provide an insight into the structure of electrical conductivity of the lithosphere before and after the earthquake. The more intense variations in the electric conductivity are observed in the zone of the deep faults. These variations are related to the changes in the porosity and saturation of the rocks by the highly mineralized fluids.  相似文献   

14.
A rigorous singular perturbation theory is developed to estimate the electric field E produced in the mantle M by the core dynamo when the electrical conductivity σ in M depends only on radius r, and when |r?rln σ| ? 1 in most of M. It is assumed that σ has only one local minimum in M, either (a) at the Earth's surface ?V, or (b) at a radius b inside the mantle, or (c) at the core-mantle boundary ?K. In all three cases, the region where σ is no more than e times its minimum value constitutes a thin critical layer; in case (a), the radial electric field Er ≈ 0 there, while in cases (b) and (c), Er is very large there. Outside the critical layer, Er ≈ 0 in all three cases. In no case is the tangential electric field ES small, nearly toroidal, or nearly calculable from the magnetic vector potential A as ??tAS. The defects in Muth's (1979) argument which led him to contrary conclusions are identified. Benton (1979) cited Muth's work to argue that the core-fluid velocity u just below ?K can be estimated from measurements on ?V of the magnetic field B and its time derivative ?tB. A simple model for westward drift is discussed which shows that Benton's conclusion is also wrong.In case (a), it is shown that knowledge of σ in M is unnecessary for estimating ES on ?K with a relative error |r?r 1nσ|?1from measurements of ES on ?V and knowledge of ?tB in M (calculable from ?tB on ?V if σ is small). Then, in case (a), u just below ?K can be estimated as ?r×ES/Br. The method is impractical unless the contribution to ES on ?V from ocean currents can be removed.The perturbation theory appropriate when σ in M is small is considered briefly; smallness of σ and of |r?r ln σ|?1 a independent questions. It is found that as σ → 0, B approaches the vacuum field in M but E does not; the explanation lies in the hydromagnetic approximation, which is certainly valid in M but fails as σ → 0. It is also found that the singular perturbation theory for |r?r ln σ|?1 is a useful tool in the perturbation calculations for σ when both σ and |r?r ln σ|?1 are small.  相似文献   

15.
The continuous increase in concentration of greenhouse gases in the atmosphere is expected to cool higher levels of the atmosphere. There is some direct and indirect experimental evidence of long-term trends in temperature and other parameters in the mesosphere and lower thermosphere (MLT). Here we look for long-term trends in the annual and semiannual variations of the radio wave absorption in the lower ionosphere, which corresponds to the MLT region heights. Data from central and southeastern Europe are used. A consistent tendency to a positive trend in the amplitude of the semiannual wave appears to be observed. The reality of a similar tendency in the amplitude of the annual wave is questionable in the sense that the trend in the amplitude of the annual wave is probably induced by the trend in the yearly average values of absorption. The phases of both the annual and semiannual waves display a forward tendency, i.e. shift to an earlier time in the year. A tentative interpretation of these results in terms of changes of the seasonal variation of temperature and wind at MLT heights does not contradict the trends observed in those parameters.  相似文献   

16.
In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations (CSs), as well as discharge and sediment transport at 3 Gauging Stations (GSs) are used to assess the features of sediment transport in the Kuye River. The rtmoff modulus (defined as the annual average discharge per unit area, L/(s·km^2)) and the sediment transport modulus (defined as the annual suspended sediment transport per unit area, t/(yr km^2)) are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m^3/s in August with an average monthly sediment concentration of 88.9 kg/m^3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m^3 and occurs in July, which has an average discharge of 42.6 m^3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye River is largest in February and then decreases until June. In July, the average monthly median grain size of suspended load approaches another peak and decreases until September. Then, the median grain size of suspended load starts to increase until February of the following year. However, the average monthly median grain size of suspended load in the Yellow River at Toudaoguai and Longmen GSs is the smallest between early summer and late fall The median grain size in the Yellow River starts to increase in November and approaches the largest size in January.  相似文献   

17.
Abstract

The basin area of the Ganges River in Bangladesh is extremely dependent on a regular water supply from upstream to meet requirements for agriculture, fisheries, navigation, salinity control, and domestic and industrial sectors. In 1975, India commissioned a barrage on the Ganges River at Farakka to divert a significant portion of the dry season flow in order to make the Calcutta Port navigable. Statistical analyses of discharge and water level data have been carried out to determine if significant changes have occurred in the hydrology of the Ganges system in Bangladesh in the post-Farakka period. Siltation of the Gorai River (an offtake of the Ganges River) has also been examined using the stage-discharge relationship and regression analysis. The analyses show that the diversion has caused considerable hydrological changes in the Ganges system in Bangladesh. The water supply in the dry season has been reduced substantially, while siltation of the Gorai River has increased significantly.  相似文献   

18.
Variations in the Caspian Sea Level in the Historic Epoch   总被引:1,自引:0,他引:1  
Reconstruction of variations in the Caspian Sea level is proposed based on the results of investigations of deposits in the Agrakhan sand bar and bays (or former bays) of the eastern sea coast. The history of sedimentation in particular regions is reconstructed by the radiocarbon dating. Generalized data on the age of deposits are used to construct the most likely temporal course of variations in the sea level within the historic epoch.  相似文献   

19.
Geomagnetism and Aeronomy - The evolution of the magnetic configuration in the solar corona is studied. The curvature of the K-corona helmets obtained from an analytical approximation of the...  相似文献   

20.
X-ray intensity variations in the surface layer of the atmosphere during precipitation in Apatity and Spitsbergen were analyzed. Based on a comprehensive system of monitoring over the radiation background, X-ray radiation variations were detected. These variations were found to be associated with meteorological processes in the lower atmosphere. X-ray energy spectra were obtained under good weather and precipitation conditions. These spectra have no characteristic lines inherent to radionuclides. Additional studies make it possible to suggest that the growth in X-ray radiation during precipitation is mainly caused by braking radiation of energetic electrons additionally accelerated by electric fields in rain clouds.  相似文献   

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