Initially, three WAB’s were mobilized with a plan to stack the barriers below the sections where the scale producing formation was thought to be encountered. After the 12 1/4″ section was drilled to total depth it was determined that only two WAB’s would be required to provide isolation.
The first WAB was successfully installed with the top at 10,273 ft (3,131.18 m) MD; the second at 10,199 ft (3,108.65 m) MD. Both WAB’s were set after the cementing operation by applying pressure to the 10 3/4” x 9 5/8″ casing string.
The WAB’s, designed to independently isolate the formation in the case of poor cement, provided a complimentary solution with the cement in this application. This solution provided additional confidence for the required isolation and did so without any reduction to the ID of the production string.
The well has been returned to production without the previous scaling issues reoccurring, thus verifying the two-part cement / WAB solution and providing the operator more reliable production.
The WAB provided a solution that, because of its rugged construction and low upset OD, could pass through the sidetrack window. Utilized in conjunction with cement the risk of having to re-drill the well or sidetrack again due to poor cement was eliminated. Delivered within a tight time frame, the operator was very satisfied with the execution and results.