CSAMT法在锦江盆地页岩气勘探中的应用研究

发布时间：2018-06-05 07:30

本文选题：CSAMT + 锦江盆地　；参考：《东华理工大学》2017年硕士论文

【摘要】：锦江盆地处于鄱阳湖盆地南缘,从盆地类型、所处区域大地构造位置、盆地盖层、沉积相以及区域致密油藏赋存环境等条件分析,且盆地内二叠系乐平组地层厚度较大、有机质丰度高、保存比较好,总体上具备了出现致密油藏的一些基本条件。目前,盆地所进行的油气资源调查工作多处于区域评价阶段,研究区需要调查锦江盆地北斜坡地层结构特征及断裂构造发育分布情况,并结合地质、测井等资料,分析异常分布,为地质调查井的设置提供有利靶区位置。可控源音频大地电磁法勘探深度适中(人类采矿活动深度范围)、抗干扰能力强、纵横向分辨力好、工作效率高、拥有测深和剖面双重研究等优点,是地质勘查工作中进行地质立体填图、寻找和确定地质构造的有效手段。论文详细探讨了CSAMT采样参数的选择原则,进行了收-发距的选择试验工作,研究了提高采样数据质量所采取技术措施。为了提高反演解释的精度,论文着重对原始数据的编辑圆滑去噪处理、近场源效应、静态效应以及数据反演算法等方面进行了详细的研究。原始数据的编辑圆滑去噪处理中,数据圆滑去噪采用了参照相位校正法,飞点剔除采用了相邻点比较法和一维反演剔除圆滑技术进行处理。讨论了近场源和静态校正方法。根据搜集的研究区的地质、水文及地球物理资料,通过对所得到的CSAMT电磁测深曲线类型图、视电阻率-频率断面图和相位-频率断面图的的定性分析,对剖面进行了初步分层,在此基础上进行了Bostick一维反演,以对区内地层结构、地质构造等特征有大致的了解,其反演结果作为二维反演的初始模型。结合现场露头岩性测试、井旁CSAMT测深资料,采用了二维带地形非线性共轭梯度法进行二维反演,使CSAMT解释成果与已知地质成果对应较好,避免解释的多解性,让解释更加深化和可信。通过以上研究工作,基本查明了研究区电性结构及构造空间分布特征,对研究区深部地层进行了层位识别与划分,确定了二叠系乐平组地层的埋深和厚度,为预测研究区页岩气以及致密油气资源成矿远景区、评价盆地的整体油气资源潜力提供有力的物探依据。
[Abstract]:Jinjiang basin is located in the southern margin of Poyang Lake basin. The basin type, regional tectonic location, basin cap, sedimentary facies and the environment of regional tight reservoir are analyzed, and the formation thickness of Leping formation of Permian system in the basin is relatively large. The organic matter abundance is high, the preservation is good, and it has some basic conditions for the appearance of tight reservoir. At present, the investigation of oil and gas resources in the basin is mostly in the stage of regional evaluation. It is necessary to investigate the stratigraphic structure characteristics of the northern slope of Jinjiang Basin and the distribution of fault structures, and to combine with geological, logging and other data. The distribution of anomalies is analyzed to provide favorable target location for the setting of geological survey wells. The controllable source audio frequency magnetotelluric method has the advantages of moderate depth (range of human mining activity, strong anti-interference ability, good longitudinal and horizontal resolution, high working efficiency, double research of sounding and profile, etc.) It is an effective means to search and determine geological structure in geological exploration. In this paper, the selection principle of CSAMT sampling parameters is discussed in detail, the selection test of receiving and sending distance is carried out, and the technical measures to improve the quality of sampling data are studied. In order to improve the accuracy of inversion interpretation, the paper focuses on the original data editing smooth denoising processing, near field effect, static effect and data inversion algorithm. In the original data editing and smoothing denoising, the reference phase correction method is used for the data smooth denoising, and the adjacent point comparison method and one-dimensional inversion knockout technique are used for the flight point elimination. The near field source and static correction method are discussed. Based on the geological, hydrological and geophysical data collected from the study area, the profile is preliminarily stratified by qualitative analysis of the obtained CSAMT electromagnetic sounding curve type diagram, apparent resistivity frequency section and phase frequency section. On the basis of this, Bostick one-dimensional inversion is carried out to get a general understanding of the stratigraphic structure and geological structure in the area, and the inversion results are used as the initial model of two-dimensional inversion. Combined with field outcrop lithology test and CSAMT bathymetric data near wells, two-dimensional inversion is carried out by using two-dimensional topographic nonlinear conjugate gradient method. The results of CSAMT interpretation correspond well with known geological results and avoid the multi-solution of interpretation. Make the explanation deeper and more credible. Through the above research work, the electrical structure and the structural spatial distribution characteristics of the study area are basically ascertained, the deep strata in the study area are identified and divided, and the buried depth and thickness of the strata of the Permian Leping formation are determined. It provides a powerful geophysical basis for predicting the metallogenic prospect of shale gas and dense oil and gas resources in the study area and evaluating the whole oil and gas resource potential of the basin.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13;P631.325

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