Unwanted water production may adversely affect well economics because of water-disposal costs, environmental issues, and reduced hydrocarbon production. This paper presents examples of how openhole and cased-hole logs can help determine the type and location of water entry, and indicate appropriate conformance treatments. Selected logs run following the treatments are used to evaluate the treatments. The cost of running the logs and applying the indicated conformance treatments is compared with the cost of water disposal and declining petroleum production.

Specific examples show that casing leaks, cement channels, coning, and watered-out reservoirs may all be easily identified and located through the use of openhole, production, pulsed neutron, casing inspection, and cement evaluation logs. Not all of these logs need be run in every well; thus, in each well, existing information was thoroughly studied to determine the most cost-effective diagnostic logging program.

The diagnostic information provided by the logs was useful in selecting appropriate conformance treatments. Many of the same logs used in diagnosing the water-production problems were found to be valuable in evaluating the effectiveness of the performed treatment. In some cases, follow-up treatments were suggested by the evaluation of the initial treatment and were the difference between successful rejuvenation of hydrocarbon production and continued declining well performance.

The costs of the logs used for conformance diagnosis and treatment evaluation were compared to the possible long-term costs of water disposal, environmental considerations, and reduced production from the well and were found to be relatively inexpensive.

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