Back-Reaming Rotary Steering

摘要

A rotary steerable system (RSS) having multiple steering pads, a valve to sequentially actuate the plurality of steering pads, and a back-reaming bit formed by multiple cutting elements carried by each of the steering pads. While rotating the drill string, the RSS, and the drill bit, the valve and/or the controller are operated to sequentially actuate the steering pads to operatively urge the RSS and the drill bit away from a longitudinal axis of the wellbore, thus steering the wellbore drilling direction. Thereafter, while rotating the drill string, the RSS, and the drill bit, the valve and/or the controller are operated to simultaneously actuate each of the steering pads to operatively urge at least one of the cutting elements on each of the steering pads into contact with a sidewall of the wellbore, thus back-reaming the wellbore.

主权项

1. A system for drilling a wellbore, comprising:
a rotary steerable system (RSS) at least indirectly coupled between a drill string collar and a drill bit, wherein the RSS comprises:
a housing;a plurality of steering pads circumferentially spaced around the housing, wherein each of the plurality of steering pads is actuatable to radially extend away from the housing independent of the other ones of the plurality of steering pads, and wherein at least one of the plurality of steering pads comprises a back-reaming bit;a valve; anda controller, wherein the valve and the controller are collectively operable to:
sequentially actuate ones of the plurality of steering pads to substantially decentralize the RSS relative to the wellbore; andsimultaneously actuate each of the plurality of steering pads to substantially centralize the RSS relative to the wellbore, thus urging the back-reaming bit into contact with a sidewall of the wellbore.