New Image Process Technique Reveals New Hidden Formation Structures Using Anisotropy and Dip Images

摘要

A new image processing technique has been developed in which resistivity-based image data is used to create new images based on anisotropy. The advantage of imaging tools is that they can provide high resolution geological information in 3 dimensions (i.e., vertically and azimuthally around the borehole). Therefore, it is possible to interpret this data in more detail than with logs that produce only depth-associated information. Consider a resistivity imager that takes an array of measurements around the borehole. This information is composed of an array of measurements much like the pixels in a photograph. These pixels can be displayed so that the position of the points is aligned with depth in the vertical axis and angular displacement in the horizontal axis in a frame of data. Based on the spatial orientation of the data, it is possible to upscale these points to determine the up-scaled horizontal (Rh) and vertical resistivity (Rv) associated with these points. The entire frame of data is resolved into a single-valued point with anisotropy. By repositioning the center point of the frame, a new anisotropy is then determined and an image log is created by processing the entire image. This upscale anisotropy image assumes that the anisotropy is relative to the borehole. In another step, the axis of the data frame is rotated until a minimum anisotropy is determined, resulting in anisotropy and a dip value associated with that point. As a result, both an anisotropy and dip image can be created by processing the entire image in this manner. These new anisotropy and dip angle images open up an entirely new way of analyzing image data and reveal hidden structures that are not readily apparent in the original image. This new image processing method is used to analyze resistivity image logs, and the results show dramatic new images that enhance the understanding of the geologic structures. .