综合物探技术在深水井场钻前风险评价中的研究与应用

发布时间：2019-06-11 05:39

【摘要】：海洋地质灾害的产生有其一定的地理、地形地貌与地质背景,各类海洋地质灾害的成因机制复杂且各不相同。随着海洋资源的开发与海洋工程的建设的迅猛发展,越来越多的受到海洋地质灾害的影响。为了规避海洋地质灾害的风险,往往需要进行相应的物探调查。这些调查方法各具特色,各自从不同的方向出发,通过不同的手段,解决了相应的问题,但仅仅靠其中某种方法难以达到良好效果。综合物探方法能从多方面获取更大量的数据信息,进而对地质灾害的形成条件和特点进行综合分析,有效提高物探信息的准确性和有效性,降低或避免海底地质灾害对海上钻井作业等生产活动的不利影响。本论文首先对三维地震、多波束测深、浅地层剖面和侧扫声呐等调查方式的原理进行了论述与分析,接着以我国南海某深水井场采集资料为例,对资料进行精细处理,并进行海底地形地貌及地质特征划分,识别出可能危害海上钻井的地质灾害类型,分析其特征与分布规律。通过多波束测得的水深数据,对井场的水深地形、海底坡度进行分析,并给出建议；通过对侧扫声呐图像的判断,划分出海底障碍物及声学异常反射区,描述并评价可能存在的海底各种灾害地质的类型特征以及其对工程的影响；通过对中浅地层剖面资料的综合分析对比,依据浅地层沉积特征及内部反射结构的变化情况,对该井场浅地层进行了地层划分与解释；对三维地震数据体进行了振幅分析,划分了地层中的振幅异常区,并对研究区地质灾害风险进行评价。结果表明,研究区内主要地质灾害类型为陡坡、海底滑坡、海底麻坑、天然气水合物、块体搬运沉积等,其中,海底陡坡、浅层气、断层和块状搬运体等直接影响着预定井位处的钻井活动。基于对解释成果的综合分析,本文给出了钻井适宜性分布图,同时实际钻井结果验证了本论文结论的准确性,从而间接证明了本论文所用方法的科学性。本论文所用的综合物探方法,可作为今后进行类似海洋开发活动的一种参考和借鉴。
[Abstract]:The occurrence of marine geological disasters has its certain geography, topography, geomorphology and geological background, and the genetic mechanism of all kinds of marine geological disasters is complex and different. With the development of marine resources and the rapid development of marine engineering, more and more marine geological disasters are affected. In order to avoid the risk of marine geological disasters, it is often necessary to carry out the corresponding geophysical survey. These investigation methods have their own characteristics, each from different directions, through different means to solve the corresponding problems, but only by one of the methods can not achieve good results. The comprehensive geophysical exploration method can obtain more data information from many aspects, and then make a comprehensive analysis of the forming conditions and characteristics of geological disasters, so as to effectively improve the accuracy and effectiveness of geophysical exploration information. Reduce or avoid the adverse effects of seafloor geological disasters on offshore drilling and other production activities. In this paper, the principles of three-dimensional earthquake, multi-beam bathymetric, shallow formation profile and side scan Sonar are discussed and analyzed. Then, taking the data collected from a deep water well site in the South China Sea as an example, the data are carefully processed. The seafloor topography and geomorphology and geological characteristics are divided, and the types of geological hazards that may endanger offshore drilling are identified, and their characteristics and distribution laws are analyzed. Based on the water depth data measured by multi-beam, the water depth topography and seafloor slope of the well site are analyzed, and some suggestions are given. Based on the judgment of side scan Sonar images, the seafloor obstacles and acoustic abnormal reflection areas are divided, and the types and characteristics of various hazards that may exist on the seafloor and their influence on the project are described and evaluated. Through the comprehensive analysis and comparison of the profile data of the middle and shallow strata, according to the sedimentary characteristics of the shallow strata and the changes of the internal reflection structure, the shallow strata of the well site are divided and explained. The amplitude analysis of 3D seismic data volume is carried out, the amplitude anomaly area in strata is divided, and the risk of geological disaster in the study area is evaluated. The results show that the main types of geological hazards in the study area are steep slope, seafloor landslide, seafloor pit, natural gas hydrate, block transport deposition and so on, in which the seafloor steep slope, shallow gas, etc. Faults and block moving bodies directly affect the drilling activity at the predetermined well location. Based on the comprehensive analysis of the interpretation results, this paper gives the distribution map of drilling suitability, and the actual drilling results verify the accuracy of the conclusion of this paper, which indirectly proves the scientific nature of the method used in this paper. The comprehensive geophysical exploration method used in this paper can be used as a reference for similar marine development activities in the future.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE52

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