casedhole

Casedhole refers to a section of a wellbore that has been lined with casing and cemented in place. This is in contrast to an "openhole" section, which is uncased. Casing is a large diameter pipe that is run into the wellbore to support the walls of the formation, prevent collapse, and isolate different zones. Once the casing is run, cement is pumped into the annular space between the casing and the borehole wall. This cement slurry hardens and forms a strong, impermeable barrier.

Casedhole logging, a type of well logging, is performed after the casing and cement have been placed. This is a common practice in oil and gas wells, as well as water wells and geothermal wells. Casedhole logs are used for a variety of purposes, including evaluating the cement bond quality, detecting leaks in the casing, identifying and quantifying hydrocarbon or water saturation in the formation behind the casing, and monitoring changes in the wellbore over time. Techniques like cement bond logging (CBL) and variable density logging (VDL) are specifically designed to assess the integrity of the cement job. Other casedhole logs, such as pulsed neutron logs, can be used to measure formation properties even through the casing and cement. This allows for continued reservoir evaluation and management throughout the life of the well.