METHOD AND APPARATUS FOR PERFORMING WIRELINE LOGGING OPERATIONS IN AN UNDER-BALANCED WELL

摘要

A method and an apparatus log an underbalanced open hole well without killing the well or causing formation damage to maintain well control during the process. The installation of the well logging equipment is accomplished while holding the underbalanced open hole at its optimal pressure, then conveying the logging string on a drill string into the open hole portion to total depth and logging while removing the logging string from the total depth to be logged with a cable side entry sub. The invention also provides a unique configuration of equipment to accomplish the logging using what is normally referred to as tough logging condition techniques.