重力全张量数据联合欧拉反褶积法研究及应用

全张量测量技术是在空中或海上用加载了多个加速度计的移动平台技术测量位场的五个独立分量.各张量分量包含不同方向的地下地质体信息,水平张量分量T_(xx)、T_(yy)、T_(xy)、T_(xz)、T_(yz)通常用于识别和映射与地质构造或地层变化有关的测量区域中的目标,垂直张量分量Tzz用于估计深度.然而,这些分量传统上是彼此分开解释,经常遇到错失关键信息的风险.本文所用全张量欧拉反褶积是在单独z方向的欧拉反演基础上发展而来的,它融合了重力异常垂直分量以及其三个方向导数、水平分量以及其三个方向导数.全张量数据信息得以有效应用的同时,欧拉反褶积结果也比常规欧拉反褶积结果更加收敛.最后,结合美国墨西哥湾地区实测航空FTG数据,用重力梯度张量数据进行联合欧拉三维反演研究,有效的识别岩盖的边界信息,划分岩盖范围,为进一步研究盖层底下深部复杂地质情况提供可靠的解释结果.

The study on the joint Euler deconvolution method of full tensor gravity data

Gravitational Full Tensor Gradient (FTG) data acquired on airborne and marine platforms measure five independent tensor components that collectively describe a total gravity field. The components capture unique signature pattern which is related to specific attributes of target geology. The horizontal tensor components (T_xx, T_yy, T_xy, T_xz and T_yz) are commonly used to identify and map lineaments associated with structural or stratigraphic changes or target geometry in a survey area. The vertical tensor component T_zz is used to estimate depth. However, these components have traditionally been interpreted separately from one another and we often encounter the risk of missing key information. The full tensor Euler deconvolution (FTED) is developed from the z direction. Furthermore, Euler deconvolution combines the individual components of horizontal tensor and its gradients, vertical tensor and its gradients. The full tensor data is validly applied, and the convergence of the FTED results are faster than the conventional Euler deconvolution results. Finally, combining with the measured data of AIR-FTG gravity in the Gulf of Mexico, we verify that the FTED method can effectively identify the boundary information of the cap-rock, which can provide reliable interpretation result for further study of the deep complex geology.