Abstract: A well drilling system includes a flow control device regulating flow from a rig pump to a drill string, the flow control device being interconnected between the pump and a standpipe manifold, and another flow control device regulating flow through a line in communication with an annulus. Flow is simultaneously permitted through the flow control devices. A method of maintaining a desired bottom hole pressure includes dividing drilling fluid flow between a line in communication with a drill string interior and a line in communication with an annulus; the flow dividing step including permitting flow through a flow control device interconnected between a pump and a standpipe manifold.

Abstract: Methods and systems for identifying and sealing a water zone in a formation employ underbalanced drilling techniques and injection of a conformance fluid into a wellbore drilled thereby. A return wellbore fluid is monitored in real-time utilizing a fluid analysis system in fluid communication with return wellbore fluids in order to identify the water zone in the formation. When the water zone is identified, drilling is suspended, and the wellbore may be brought to a slightly overbalanced condition. A barrier fluid pill is injected into the wellbore via a drillstring. Immediately following the barrier fluid pill injection, a conformance fluid is injected, “chasing the barrier fluid pill”. Pressures in the drillstring and the wellbore annulus are controlled in order to position the pill. The pill functions as a barrier to contain and assist injection of the conformance fluid into the water zone, thereby sealing the water zone.

Abstract: Methods and systems for identifying and sealing a water zone in a formation employ underbalanced drilling techniques and injection of a conformance fluid into a wellbore drilled thereby. A method includes monitoring a return wellbore fluid in real-time utilizing a fluid analysis system in fluid communication with return wellbore fluids in order to identify the water zone in the formation. When the water zone is identified, drilling is suspended, and the wellbore may be brought to a slightly overbalanced condition. A barrier fluid pill is injected into the wellbore via a drillstring. Immediately following the barrier fluid pill injection, a conformance fluid is injected, “chasing the barrier fluid pill”. Pressures in the drillstring and the wellbore annulus are controlled in order to position the pill. The pill functions as a barrier to contain and assist injection of the conformance fluid into the water zone, thereby sealing the water zone.

Abstract: A well system can include an accumulator in communication with a wellbore, whereby the accumulator applies pressure to the wellbore. A method of maintaining a desired pressure in a wellbore can include applying pressure to the wellbore from an accumulator in response to pressure in the wellbore being less than the desired pressure. Another well system can include a dampener in communication with a wellbore isolated from atmosphere, whereby the dampener mitigates pressure spikes in the wellbore.

Abstract: A well drilling system includes a flow control device regulating flow from a rig pump to a drill string, the flow control device being interconnected between the pump and a standpipe manifold, and another flow control device regulating flow through a line in communication with an annulus. Flow is simultaneously permitted through the flow control devices. A method of maintaining a desired bottom hole pressure includes dividing drilling fluid flow between a line in communication with a drill string interior and a line in communication with an annulus; the flow dividing step including permitting flow through a flow control device interconnected between a pump and a standpipe manifold.

Abstract: A well drilling system includes a flow control device regulating flow from a rig pump to a drill string, the flow control device being interconnected between the pump and a standpipe manifold, and another flow control device regulating flow through a line in communication with an annulus. Flow is simultaneously permitted through the flow control devices. A method of maintaining a desired bottom hole pressure includes dividing drilling fluid flow between a line in communication with a drill string interior and a line in communication with an annulus; the flow dividing step including permitting flow through a flow control device interconnected between a pump and a standpipe manifold.

Abstract: A well drilling system includes a flow control device regulating flow from a rig pump to a drill string, the flow control device being interconnected between the pump and a standpipe manifold, and another flow control device regulating flow through a line in communication with an annulus. Flow is simultaneously permitted through the flow control devices. A method of maintaining a desired bottom hole pressure includes dividing drilling fluid flow between a line in communication with a drill string interior and a line in communication with an annulus; the flow dividing step including permitting flow through a flow control device interconnected between a pump and a standpipe manifold.

Abstract: A well system can include an accumulator in communication with a wellbore, whereby the accumulator applies pressure to the wellbore. A method of maintaining a desired pressure in a wellbore can include applying pressure to the wellbore from an accumulator in response to pressure in the wellbore being less than the desired pressure. Another well system can include a dampener in communication with a wellbore isolated from atmosphere, whereby the dampener mitigates pressure spikes in the wellbore.

Abstract: A robotic system for minimally invasive surgery includes a surgical tool and a docking station for restraining movement of the surgical tool to four degrees of freedom about an incision point in a patient. The docking station includes a plurality of actuators for moving the surgical tool relative to the incision in the patient, and a controller operably connected to the actuators so that movement of the surgical tool may be collaboratively controllable both actively by the controller and manually by a surgeon. Desirably, the surgical tool and the docking station are releasably attachable together. Also disclosed is a computer implemented method employing a first docking station attachable to a suturing surgical tool and a second docking station attachable to gripping surgical tool for autonomously tying a knot in suturing.