Advances in Downhole Corrosion Evaluation

Since the decline in oil prices, the trend in the industry has been toward the maintenance of producing, existing reserves and away from the cost of trying to find new ones. The concern over the longevity of producing fields and new environmental legislation has led to an increased interest in corrosion control of downhole tubulars. If in situ complete and accurate measurements of downhole casing and tubing conditions can be made, the corrosion engineer can best determine the optimum cost-saving action to be taken. The consequences of not accurately evaluating the downhole condition relate to safety and environmental concerns, including blowouts and pollution, as well as loss of production. Recent developments have led to the introduction of several new tools specifically designed for the evaluation of casing and tubing deterioration. These new developments coupled with improvements to existing measurement systems now provide accurate techniques for interpreting the integrity of casing and tubing. The focus of this paper will be on the introduction and principles of measurement of this new technology. Resulting improved interpretation techniques will be demonstrated from actual field logs.