Re-Development of the Sidki Field: A Drilling Case History
Authors: Holt Charles A. , Triolo David , Metwally Ibrahim , Fahmy Helmy 
Published: December 2007

This paper discusses the re-development of the offshore Sidki Field situated in the Gulf of Suez, Egypt. The original Sidki platform was struck by a cargo vessel on December 8, 1989. Due to the massive damage, the 9 wells were abandoned and the platform removed. Remaining reserves, 25 MMSTB, justified re-development of the field. The new platform position was optimized to minimize anti-collision with the original wells while optimizing the trajectories and footage required to re-drill based on nine (9) new bottom hole locations. A detailed post analysis of the original wells drilled from 1977 through 1987 was performed. Historical problems included high pressure salt water flows, differential sticking, lost circulation, and pressure transitions. This paper includes the changes and key lesson's from the original development to the re-development, including the application of horizontal wells to accommodate for reduced reservoir energy not anticipated between last production and the redevelopment. The lower than anticipated reservoir pressures and the application of horizontal wells created a new set of challenges for the Sidki drilling team. Problems and solutions of drilling these four (4) horizontal wells are presented in the paper.

Introduction

The original Sidki platform, Sidki "A", was a 12 slot load bearing platform located in 278 ft of water on the East side of the GOS North bound shipping lane. At the time of the collision, nine (9) wells were producing approximately 5000 BOPD The majority of the production was from the Nubia formation, with two wells producing from the Kareem. The Nubia, Paleozoic to Cretaceous age non-marine to shallow water marine well sorted sandstone having 15% porosity and 160 milli-darcy permeability. Nubia thickness ranges from 700-1000 ft in the Sidki area. The Kareem is Miocene age sandstone ranging to 170 ft thick in the Sidki field. In addition to the production loss from the Sidki wells, production from two Southern 605 platforms routed through the Sidki "A" platform was lost, an additional 1500 BOPD.

Through the course of developing the original field ten (10) wells had been drilled including numerous geological and mechanical sidetracks. The new platform, Sidid "B", was positioned approximately 1000 ft from the original platform in order to minimize collision avoidance with the original wells. The replacement wells were targeted near the original wells, but with sufficient distance to avoid any possible formation damage caused by the abandonment of the original wells. Figure 1 shows the original wellpaths and the targets identified for the re-development. An extensive drilling post analysis was conducted which resulted in improved mud systems, clearly defined casing points, and improved bit selections.

The new Sidki "B" platform is also a 12 slot load bearing platform. The platform was special purpose built to include no batter on the South side rig approach so that a jack-up style drilling rig with cantilever skidoff capabilities could approach the platform. The cantilever package was skidded onto the platform and the barge remained at the side of the platform in a tender position. Although used in other locations around the world, this technique is new to the drilling industry and a first for the 605 and Egypt.

Since all the bottom hole locations were known, the platform installation barge installed 10-30" conductor strings using directional drive shoes, orienting each of the conductors toward the respective well targets. The rig initially cleaned out each conductor and a gyro was run to determine the final location of the conductor drive shoes.