海洋磁力梯度测量技术在水合物勘探中的应用

Application of the Marine Magnetic Gradient Measurements to the Exploration of Gas Hydrate

在天然气水合物勘探中,海底的泥底辟和泥火山构造是重要的研究对象.在高分辨率地震剖面解释中,直接识别泥底辟构造存在一定困难,主要表现为泥底辟构造和火成岩侵入体在形态上十分相似,容易造成解释的多解性.本文就目前天然气水合物调查中存在的这些特殊技术问题,通过对海上高精度磁力测量技术方法研究,在南海北部东沙海域的海上试验,试验结果的系统研究分析以及磁测和地震剖面两种手段的综合解释,成功地尝试了用高精度海洋磁测成果中的磁力总场和梯度变化特征来识别水合物勘探中高分辨率地震剖面上的泥底辟构造真伪的技术方法.

For the exploration of gas hydrates, it is of great significance to study such geological structures as mud diaper and mud volcano. In the high resolution seismic profile, to directly identify the Diapir is often difficult due to the much similarity between diapir and the invasion of igneous rock and thus leading to multi- resolution. Surrounding these special problems met in gas hydrates exploration and through study of high precision magnetic survey, the sea test by R/V Haiyang IV which is owned by Guangzhou Marine Geological Survey in Dongsha area of the South China Sea, systematically analysis of the test result and combination interpretation of magnetic survey with seismic profile, the paper successfully employs the method to recognize the truth or false of the diapir in seismic profile by integrating total field of high precision marine magnetic measurement with its gradient change.