毕业论文厄瓜多尔奥连特盆地磁力场特征与磁性体分布part1.rar

             

摘 要：南美地区拥有丰富的油气资源，是我国重点海外战略目标区之一，在我国海外油气发展中占据越来越重要的地位。奥连特（Oriente）盆地位于南美次安第斯前陆盆地链北部，是厄瓜多尔最重要的含油气盆地之一，已有大量地质研究涉及该盆地的形成与构造演化,但在磁力场特征及磁性体分布特征方面的研究却较少。本文以奥连特盆地的航磁ΔT异常为基础，应用SUFER系统模拟该地区的磁场特征做了球体正演模型，应用RIGS系统对数据做低磁纬度化极、正则化滤波、向上延拓、滑动平均、水平方向梯度模、垂向二阶导数处理，通过研究，深入分析并总结了奥连特盆地的磁异常特征和磁性体分布情况，为本地区油气资源勘探和资源评价提供参考和依据。

　　　本文在低磁纬度化极的基础上，运用垂向二阶导数、滑动平均、正则化滤波等进行了场的分离，得到了研究区磁异常向上延拓图、导数异常图、水平总梯度异常图等基础图件，对研究区的磁力场进行了分区和特征解释，结合地质资料对奥连特盆地的磁资料进行综合研究，推测出研究区断裂构造体系和基底的起伏特征，采用正则化滤波，圈定了局部异常，并分析了异常的基本特征。取得的结论如下：

    (1)球体模型对比分析的结果表明，异常采用低磁纬度化极后得到的正异常的规模和水平面投影位置恰能反应异常的基本形状和投影位置。

　　　(2)研究区内北部异常相对较弱且在地质图上地表没有古老地层出露，异常位置与剖面图中基底隆起位置基本一致，推测异常是由基底隆起所致。

　　　(3)研究区内西南部区域高异常在剖面图上其走向与逆冲推覆构造走向基本一致，推测异常是由逆冲构造引起，也可能是盖层中侵入岩引起。

　　　(4)研究区内东部幅度高且范围大，强磁异常的走向与图中基底的深大断裂走向一致推测该异常是由其引起。

　　　

关键词：厄瓜多尔；奥连特盆地；航磁ΔT异常；低磁纬度化极；磁性体分布 

Magnetic Field Characteristics and The Distribution of Magnetic Body at Oriente Basin in Ecuador

Abstract：There are abundant oil-gas resources in South America, it is also the focus of overseas strategic target in our country and becoming more and more important in overseas oil-gas resource development. Orient Basin is located in the northern of sub-Andean foreland basin chain in South America, it is one of he most important oil-gas basins in Ecuador. there is a large number of geological studies about the formation of the basin and tectonic evolution. However, there are few studies relate to magnetic field characteristics and distribution of the magnetic body. In this paper, the study is based on aeromagnetic ΔT anomaly, We apply the Surfer system to Simulate magnetic field characteristics in the region to make some ball forward modeling. By applying the RIGS system processing the aeromagnetic data of Oriente in different ways, such as: canonical filtering, upward continuation, moving average, Horizontal gradient mode, Vertical second derivative processing. Through the research, we analyzed and summarized the characteristics of magnetic anomalies and the distribution of the magnetic body in Oriente basin, intending to provide reference and basis for the exploration of oil-gas in this area and resource assessment.

　　  We based on the magnetic polarization of low magnetic latitude making some processing, such as: canonical filtering, upward continuation, moving average, Horizontal gradient mode, Vertical second derivative processing, acquired the upward and downward continuation maps, derivative anomaly maps and horizontal total gradient maps. The gravity and magnetic anomaly are described and interpreted. Comprehensive study of gravity and magnetic data is discussed combined with geological data on the basin. Then deduced the fault structure system and The ups and downs of the basement feature in the study area. According the canonical filtering to obtained the delineation of the local anomaly. The main results and conclusions obtained are as follows:

　　  (1)The Analysis of sphere model shows that, after the magnetic polarization of low magnetic latitude the scale of the positive anomaly and the Horizontal projection location indicate the location and radius of the sphere model .

　　  (2)the anomaly in north area of the study region is Relatively weak and also have no old formation crop out in earth's surface. the position of the anomaly is basically same with the basement uplift in profile, so we infer that the anomaly is caused by it.

　　  (3)The trend of the high anomaly in south west area of the study region is basically same with the thrust fault, so we infer that the anomaly is caused by it.

　　  (4)the anomaly in east area of the study region shows a highest Amplitude and a biggest distribution, it’s trend is basically same with the discordogenic fault in basement. so we infer that the anomaly is caused by it.

Key words: Ecuador; Oriente basin; aeromagnetic ΔT abnormally; magnetic polarization of low magnetic latitude; distribution of magnetic body

目  录

1  绪言 1

1.1  选题背景、意义及课题来源 1

1.2  研究内容及技术线路 1

1.3  完成的工作量及主要成果 2

1.3.1  资料的收集及整理 2

1.3.2  地质-地球物理资料的收集和预处理 2

1.3.3  航磁资料的处理解释 2

1.3.4  取得的主要成果 2

2  研究区概况 4

2.1  自然地理概况 4

2.2  国内外研究现状 4

2.3  地质背景 5

3  航磁资料处理解释方法技术 10

3.1  航磁资料情况 10

3.2  资料处理解释流程 10

3.3  主要解释方法原理 10

3.3.1  ΔT异常化极原理 11

3.3.2  低磁纬度化极 11

3.4  资料处理方法技术 12

3.4.1  资料预处理 12

3.4.2  航磁资料的处理 13

4  球体正演模型分析对比 15

4.1  相同半径不同埋深球体模型对比 15

4.2  相同埋深不同半径球体模型对比 17

4.3  不同半径球体在相同深度不同接触关系模型对比 19

4.4  对比分析结论 21

5  磁力场特征 22

5.1  区域磁力场特征 22

5.2  局部异常特征及磁性体分布 26

6  结论 29

参考文献 31

附录A 32