Openhole Gravel Packing With Exposed Shales: Waterpack Case Histories From Underground Gas Storage Wells in Italy

Abstract

Abstract One of the major challenges in underground gas storage wells in Italy is to maximize the sand layers exposure by drilling slanted or sub-horizontal wells through several shale bodies to obtain high gas rate performances during the production and the injection cycles. This challenge has a significant effect in selection of the completion technique in these wells, which require an effective and reliable sand control for long term, and open-hole and large tubular size to minimize friction losses. Until now, standard open-hole gravel packing was the common completion in a single sand body, however in presence of shales open-hole expandable screens with annular barriers and blanks between each section of sand is the only completion option, except in fine sand environment. In this paper, we present experimental data of shale stabilizer treated-brine and three open-hole gravel packing case histories from one UGS field in Italy. In the three case studies the wells were gravel packed using shale stabilizer treated-brine in open-hole made up of sand layers containing shale, without negative impact on completion time.