Integration of a Performance Drilling Motor and a Rotary Steerable System Combines Benefits of Both Drilling Methods and Extends Drilling Envelopes

Abstract

fax 01-972-952-9435. AbstractSince their introduction in 1997, rotary steerable drilling systems have delivered significant gains in drilling efficiency. In addition to this fundamental benefit, these systems have enabled more challenging wells to be drilled at low risk with a wide range of other advantages, including improved well placement, etc.Continuous rotary drilling operations do however bring with them certain challenges which must be considered before rotary steering is selected for use. These include instantaneous penetration rate, specifications of rig rotary equipment, casing or drillpipe wear, stress on the drillstring, loss of drilling power through wellbore friction and drilling dynamics.Using high powered drilling motors, traditional performance drilling has been applied since the early 1990's to improve penetration rates by applying high power and consistent operating parameters directly to the drillbit. This has however been limited to straight holes or the most basic of directional profiles.A system has been developed which integrates a specially designed high power drilling motor within a high speed rotary steering assembly. By using this new system: • many of the challenges of continuous rotary drilling are mitigated, • more complex wells benefit from the advantages of traditional performance drilling, • existing drilling envelopes can be extended to further improve field recovery. This paper discusses the engineering design of the complete system, including the specially designed motor and high speed rotary steering system. The paper then goes on to discuss specific applications where the system should be considered for use, illustrated with results from real examples.

Steerable Motors Hold Their Own Against Rotary Steerable Systems

“…The lateral reach in the same type wells was extended to over 28,000 while improving the depth control to +/-1 ft with rotary steerable tools. 12 The maximum lateral reach while employing rotary steerable technology is now in excess of 35,000 ft. 13 As the production enhancements of horizontal wells became better understood, the economics for redevelopment of reserves from many existing fields became more attractive.…”

Novel Torque and Drag Model for Drilling Two-Dimensional High-Angle Wells

“…The most commonly used technologies for directional drilling nowadays are 25 positive displacement mud motors (PDMs) and rotary steerable systems (RSSs). Mud motors are generally less expensive, but the borehole quality of RSSs is better than that of mud motors.…”

“…24 Synthetic fluids are designed to mirror performance of OBM, without their environmental hazards. 25 positive displacement mud motors (PDMs) and rotary steerable systems (RSSs). Mud motors are generally less expensive, but the borehole quality of RSSs is better than that of mud motors.…”