The Barnett Shale field presents numerous drilling challenges. Meeting the increasing demands of natural gas requires economical development by efficient drilling of directional and horizontal wells. The standard technique for drilling S and J type directional wells was by utilizing steerable motors. This technique has several drawbacks: frequent trips to change angle of the AKO for the build/tangent/drop sections, poor hole quality due to string rotation, drillstring/BHA/casing wear, excessive cement volumes due to hole enlargements and high torque and drag due to wellbore tortuosity. Frequently the wells drilled in this field are closely spaced which require precise control of the well path to prevent collision. Steerable motors generate high wellbore tortuosity as corrections to the well path are made after every survey. Automated rib steering systems with rotating drill strings are cost prohibitive for this application.

To overcome these drilling challenges a strategy was outlined that comprised of the new non-rotating automated rib-steering system for low inclined 3-D wellbores. Research, field tests and application of innovative and sophisticated technologies has resulted in the development of this state of the art directional drilling system.

Since the introduction of the new technology many wells have been drilled in various fields of N. Texas and Canada with a build/drop rate up to 3°/100 ft. All sections of the wellbore (vertical, build, turn, tangent and drop) were performed without having to trip. Inclination of the tangent sections was maintained within +/- 0.2° of the target. Azimuth corrections were made without interrupting the drilling process and all directional operations were carried out by the system's automatic closed loop control. The new system has minimized hole enlargements, reduced torque/drag helping deliver a smooth, high quality wellbore and increased efficiency and quality of cementing operations. This has allowed the operator to log and set tubulars without incident and maximize the productivity from this field.

This innovative directional drilling system can be utilized to drill ‘S’ and ‘J’ type directional wells without string rotation, low-inclination convoluted well profiles can be drilled with precision due to constant control over inclination and azimuth. Different sections of the well are drilled without tripping by the systems closed loop control.

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