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Extended Reach Drilling (ERD) from the artificial island is particularly challenging for anti-collision, directional drilling and wellbore construction; facing various issues including but not limited to wellbore instability, hole cleaning, tortuosity, torque and drag etc., affecting the completion liner running and its ability to reach the setting depth especially in the smaller hole sizes. This paper describes the application of ground-breaking technology that enables completion liner with multiple ICDs and Swell Packers to be deployed at setting depth in ERD well maximizing oil reservoir production and saving cost. In 3D complex well profiles, while running conventional completion liner string, frictional drag is cumulated along the string, exposing the same to sinusoidal buckling which is further elevated to helical buckling and consuming the load available from surface to transfer to shoe, ultimately preventing the string to reach the setting depth. The buckling is even more severe in smaller hole sizes like 6" hole section where tapered drill string with 4" DP against 7" liner is used to run lower completion. By allowing a portion of the string to be rotated, significant amount of axial friction is converted from drag to torque and provides additional hookload at surface to push the string to TD. This selective rotation is enabled by the integration of a Swiveling Tool into the string above the Liner Hanger. The tool has been tested in a development well in an artificial island of offshore Abu Dhabi. This was the longest well drilled by operator with measured depth of 24,414 ft (Horizontal departure +/− 20,000 ft, 6" drain hole length +/− 5,200 ft). Later this technology was implemented in most of the challenging 3D complex wells and the Swiveling Tool became part of completion running string (4-1/2" Liner with ICD's and swell-able packers) based on the T&D simulation results if they indicated very little or no margin of drag available prior to string lock up which might make it impossible to reach setting depth. This paper describes a structural approach towards running 4-1/2" lower completion with ICD and swell packer in 3D-complex ERD well utilizing swiveling tool to ensure completion is run to the desired setting depth. The proposed tool can be implemented any project worldwide where buckling could prevent running lower completion and there is restriction to rotate the lower part of completion or if there are chances of having obstructions due to hole condition/geometry. |
