A Novel Technique for Determining Screen Failure in Offshore Wells: A GOM Case History

Abstract Offshore completions in the Gulf of Mexico must typically address sand control. Our industry has made significant progress with respect to sand control equipment and implementation. However, even properly designed and executed completions are subject to mechanical failure, with the first indications often being production of solids into a common separation facility. In many offshore completions, particularly sub-sea or multi-zone completions, it is often difficult and expensive to determine which well or specific completion interval has failed, most times requiring production to be shut in for diagnosis. Not until that point can a remedy be evaluated. One GOM producer engaged the services of a proppant supplier to determine whether a suite of proppants/gravel could be developed that could be uniquely identified and placed in each completion interval. In the event of proppant production to surface (mechanical failure), the surface samples would be analyzed to directly determine which interval had failed. The proppant needed to be non-radioactive yet identifiable with standard laboratory techniques. The supplier subsequently developed a methodology whereby the proppant could be "tagged" with over 20 unique markers. This paper will discuss how the tagging agents are incorporated to become a permanent component of the pellet. The results of laboratory testing will be provided, verifying that the taggant does not materially affect the performance of the proppant. In addition, the authors will review case histories where this new product was successfully placed in multi-zone frac pack completions in several deepwater GOM completions. The paper will also describe basic laboratory techniques used to successfully identify the source of proppant found in a surface choke subsequent to the frac. The economic savings provided by this novel approach will be presented, as well as other potential applications for this new product.