Drilling system, rotating control devices, and method for accessing a wellbore

A drilling system, rotating control device, and a method for accessing a wellbore may employ a rotating control device arranged to form a dynamic seal between the housing and an exterior of the string to isolate the wellbore annulus under both a positive and a negative differential pressure across the seal. The rotating control device may including a sleeve rotatively disposed within the housing and rotatively carried near a longitudinal midpoint of the sleeve by a thrust bearing assembly. One or more seal retainers may be coupled to and sealed against the sleeve, each including a resilient element disposed to slide to a first sealing position within the seal retainer under a positive differential pressure across the element and to slide to a second sealing position within the seal retainer under a negative differential pressure across the element.