Acoustic Borehole Images for Fracture Extraction and Analysis in Second Pre-pilot Drillhole of CCSD

被引：7

作者：

Zou Changchun Geodetection Laboratory China University of Geosciences Ministry of Education Beijing China ^{[100083
]}

School of Earth and Space Sciences Peking University Beijing China Shi Ge School of Earth and Space Sciences Peking University Beijing China Pan Lingzhi Geodetection Laboratory China University of Geosciences Ministry of Education Beijing China ^{[100871
,100871
,100083
]}

机构：

来源：

Journal of China University of Geosciences | 2004年 / 01期

关键词：

Chinese Continental Scientific Drilling (CCSD); acoustic borehole image; fracture; analysis;

D O I：

暂无

中图分类号：

P622 [地质普查];

学科分类号：

0818 ; 081801 ;

摘要：

Ultrasonic imaging logging provides continuous and oriented images of structures vs. depth. In the Chinese Continental Scientific Drilling (CCSD) Project, acoustic borehole images were recorded in the second pre-pilot drillhole which penetrates the metamorphic rocks. This paper focuses on fracture evaluation of the drillhole with these images. Both least square fit and a modified Hough transform are used for fracture extraction, and 269 fractures were mapped in the interval from 69.5 to 1 020 m. Most fractures dip steeply, with an average angle of 54°. Fracture dip directions are dominantly in the range of 220°-280° above the depth of 267 m, but 80°-120° in the lower zones. These observations may indicate the differences in structural movements or in-situ stress fields between the upper and lower zones in the drillhole.

引用

页码：124 / 128

页数：5