LONG REACH ROTARY DRILLING ASSEMBLY

摘要

A long reach rotary drilling assembly comprises an elongated conduit, a drill bit (122), a 3-D steering tool (118) on the conduit, and a tractor (110) on the conduit for applying force to the drill bit. The steering tool includes a telemetry section (100), a rotary section (224), and a flex section (272) assembled as an integrated system in series along the length of the tool. The flex section (226) comprises a flexible drive shaft (244) to which a bending force is applied when making inclination angle adjustments. The rotary section (224) includes a deflection housing which rotates for making a azimuth angle adjustments. The telemetry section (100) receives inclination and azimuth angle steering commands together with actual inclination and azimuth angle feedback signals for controlling course. A propulsion assembly moves the tractor with respect to the gripper (1104) while the gripper portion is in the first position. The tractor (110) applies force to the drill bit for drilling the bore along a desired course the direction of which is controlled by the 3-D steering tool (118).