Methods for Determining the Mechanical Integrity of Class II Injection Wells

摘要

The mechanical integrity of injection wells must be determined to insure that there is no significant leak in the casing, tubing or packer, and that there is no significant fluid movement through vertical channels adjacent to the injection well. Methods for mechanical integrity testing include monitoring of annulus pressure, pressure testing, temperature logging, noise logging, pipe analysis surveys, electromagnetic thickness surveys, caliper logging, borehole television, borehole televiewer, flowmeter surveys, radioactive tracer surveys and cement bond logging. Only temperature logging, noise logging and radioactive tracer surveys can be used to provide relatively definitive information regarding the presence or absence of fluid movement behind casing; cement bond logs provide information from which fluid movement may be inferred. With the exception of cement bond logging, all of the testing methods can be used to locate leaks in casing. This document describes each of the methods that can be used in mechanical integrity testing, including principles, equipment, procedures, interpretation, cost, advantages, disadvantages, and examples of each technique.