Eccentric Tool Increases Liner Size Capacity in Challenging Salt Dome Application Allowing Longest Horizontal Well in Gulf of Suez

摘要

This paper describes the successful use of eccentric tools tosolve a variety of complex downhole problems associated withdrilling through flowing salt formations in the Gulf of Suez.The tool allows simultaneous reaming and drilling withsteerable assemblies (SRWD).The SRWD technology was applied in two intervals on wellA-19, East Zeit Bay Field, as insurance against hole problemscaused on the previous wells by salt mobilization andsaltwater flows. On well A-19, the operator had to decideeither to drill with a large casing program or use theunderreaming technology while still drilling an economicwell. Additional problems involved drilling through largesalt sections, possible saltwater flows, interbeded hardlimestone/anhydrite sections and an aggressive directionalwellbore design.Without SRWD technology, the operator would have to drill awell using a large hole design, which was complicated due tothe platform considerations, casing inventories available, andthe higher costs associated with the increases of mudvolumes, and decreased penetrations rates. The operator wasable to steer the 14-inch SRWD tool to keep the wellbore ontrack at 38 degrees to the planned casing point. The lower12-1/4” build section was drilled from 38 degrees to 67degrees while turning the hole from an azimuth of 108degrees to 123 degrees with no major problems associatedwith the SRWD tools.The authors will discuss the optimization of the well design,the technology of the SRWD and the close cooperationbetween all the service companies required to help theoperator drill the longest horizontal well in the Gulf of Suezwithout sacrificing cost per foot, and making a successfulwell.