Rotating Sand Screens to TD in Korchagina ERD wells

Abstract

To extend areal coverage for maximum reservoir contact from a single offshore platform, Korchagina oil field is developed with Extended Reach (ER) wells with MD up to 8km, TVD 1.5km. The main target of Korchagina field is Neokomian sandstone formation with large gas cap that necessitates field development with horizontal ICD sand screen completions to minimize early gas breakthrough.In 2011 a task was set to work out set of solutions that would convey ICD sand screens to TD in Korchagina ER environment, with openhole coverage up to 5000m, and to design completion elements around these solutions.At planning phase industry expertise -completion practices in projects operating in similar ER environment was reviewed, and existing to date technologies to complete ER wells were analyzed.Existing technologies and practices did not provide sufficiently robust and flexible solutions for Korchagina ER environment. Hence, innovative solution was proposed -Rotating sand screens to TD, with contingency to run in stages if rotation limit is expected to be exceeded based on drilling results.Further, design of completion equipment was reviewed to accommodate high torque and rotation capability: direct wrap sand screen media with proven sand retention performance in high torque; integral centralizers, to transfer rotational motion at contact points to reduce drag; high torque connections. Paper discusses in details the solutions proposed and design of completion equipment.In 2 years 11 ERD wells were completed with TD reaching 7996m MD at 1565m TVD and openhole coverage up to 4700m. Of these 11 wells, in 3 wells actual friction factors came low enough to allow completion run conventionally, in 8 wells rotation was required at 800m-3000m off TD. The results are presented in the paper.Based on successful results of application, rotation is set as requirement for completion design for all the wells of current Korchagina field.