Simultaneous Gravel Packing and Filter-Cake Cleanup With Shunt Tubes in Openhole Completions: A Case History From the Gulf of Mexico

A case history from the Gulf of Mexico is presented in this paper for drilling and completing a horizontal openhole well with simultaneous gravel-packing and filter-cake cleanup with shunt tube screens. The openhole section was 277 ft, deviated from 85 to 90°. The producing sand was normally pressured. The drill-in fluid and gravel-pack carrier/filter-cake removal fluid selection was based upon extensive laboratory testing consisting of cleanup, compatibility, and sand-suspension-capability tests. A reservoir drill-in fluid comprising brine, starch, biopolymer, and sized calcium carbonate was chosen for the project. A viscoelastic surfactant (VES) fluid in a chelating agent solution (CAS) containing an enzyme breaker to simultaneously attack both the starch and CaCO 3 components of the filter cake was identified as the best carrier fluid for the gravel pack. Laboratory test results, field procedures, and production results are discussed in detail, along with the decision process that resulted in the selected drilling and completion plan.