Geophysical helicopter-based magnetic methods for locating wells
Geophysical helicopter-based magnetic methods for locating wells
复制标题
基于地球物理直升机的磁定位井方法
作者：
V. Kaminski;Richard Hammack;W. Harbert;G. Veloski;J. Sams;D. Greg Hodges
我们研究了准确确定废弃井和有时无证井的位置的问题，以及与地下储集层完整性和区域经济发展有关的具有挑战性和日益重要的任务。我们回顾了各种基于地球物理工作流程的半定量方法，并用在两个现场收集的航空磁场数据对这些方法进行了测试。我们的主要结论是，航空磁测是一种高价值的工具，有助于准确确定废弃井的位置和特征。在一个地点，在略有不同的高度收集了两项调查，以比较工作流程的稳健性，并允许将观测到的垂直磁梯度包括在油井检测工作流程中。我们还利用震源区异常统计(使用磁场强度及其一阶和二阶水平导数)、解析信号、倾斜导数和计算垂直梯度进行了研究。此外，我们使用了一小部分数据的三维反演来研究与井相关的磁化率分布的成功恢复，并估计了地下井的拓扑结构。恢复的磁化率体积显示出与已知井相对应的独特的垂直拉长物体。然后对这些数据集进行了最大似然估计和置信度计算，并表明可以使用这种航空全磁数据来确定和表征高置信度井的位置。
We studied the problem of determining accurately the location of abandoned and sometimes undocumented wells and the challenging and increasingly important task related to subsurface reservoir integrity and regional economic development. We reviewed a variety of semiquantitative methods based on geophysical workflows, and we tested these with airborne magnetic data collected at two field sites. Our main conclusion is that airborne magnetic surveys represent a high-value tool to aid in the accurate determination of abandoned well locations and characteristics. At one site, two surveys were collected at slightly different altitudes to compare workflow robustness and allow the observed vertical magnetic gradient to be included in well detection workflows. We also investigated using focal zone anomaly statistics (using the magnetic field intensity and its first and second horizontal derivatives), analytic signal, tilt derivative, and calculated vertical gradient. In addition, we used a 3D inversion of a small subset of data to investigate the successful recovery of well-related magnetic susceptibility distribution and estimate subsurface well topology. The recovered magnetic susceptibility volume showed distinctive vertically elongated objects that correspond to known wells. Maximum likelihood estimation and confidence calculations were then applied to these data sets and indicated that high-confidence well locations could be determined and characterized using such airborne total magnetic data.