Well logging, also known as borehole logging is the practice of making a detailed record (a well log) of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface (geological logs) or on physical measurements made by instruments lowered into the hole (geophysical logs ...

Well logging is an evaluation method in which a logging crew lowers a special tool, a sonde, into the well and then pulls it back up. As the sonde passes the formations on its way up the wellbore, it senses and measures electrical, radioactive, and acoustic (sound) properties of the rocks.

Geophysical well logs in paper format are scanned, saved, and distributed in tagged image file format (TIFF). Converting well logs from TIFF to Log ASCII Standard (LAS) formatted files is resource intensive, requiring knowledge about software and geological characteristics.

2016年7月28日 · Well logs present a concise, detailed plot of formation parameters versus depth. From these plots, interpreters can identify lithologies, differentiate between porous and nonporous rock and quickly recognize pay zones in subsurface formations.

2022年12月7日 · There are many different types of well logging, including but not limited to, resistivity, sonic, caliper, electric, seismic, and radioactivity. Each type of well logging involves a different process and provides different information about the subsurface.

Perhaps the best way to begin a study of logging is by introducing the reader to some of the basic con-cepts of well log analysis. Remember that a borehole represents a dynamic system; that fluid used in the drilling of a well affects the rock surrounding the bore-hole and, therefore, log measurements. In addition, the

2025年1月29日 · Well logs provide insight into the formations and conditions in the subsurface, aimed primarily at detection and evaluation of possibly productive horizons. Water saturation is the fraction of the pore volume of the reservoir rock that is filled with water.

Well logging, field technique used in mineral exploration to analyze the geologic formations penetrated by a drill hole. If the hole has been drilled by using coring techniques, the core provides a visual record of the formations and rock types encountered.

Geophysical well logs are widely used in geological fields, however, there are considerable incompatibilities existing in solving geological issues using well log data. This review critically fills the gaps between geology and geophysical well logs, as assessed from peer reviewed papers and from the authors’ personal experiences, in the particular goal of …

2025年3月20日 · This study addresses the challenge of improving well-logging data quality under adverse drilling conditions by applying unsupervised machine learning outlier detection techniques (UML-ODTs). Focusing on the Isolation Forest (IF) algorithm, we analyzed 13,566 and 14,880 sample points from two wells in the Songliao Basin, China, to detect and reconstruct anomalies caused by equipment ...