Abstract: A method for modifying a return fluid in a wellbore comprises disposing at least one controllable flow restrictor along a drill string in the wellbore. At least one parameter of interest is determined at at least one location along an annulus in the wellbore. Controllably actuating the at least one flow restrictor to modify a local property of a return fluid in the annulus based at least in part on the measured parameter of interest.

Abstract: Systems and methods for monitoring and characterizing fluids in a subterranean formation are provided. In one embodiment, a method for monitoring fluids in a well bore penetrating a subterranean formation is provided, the method comprising: determining an actual buoyed hookload of an apparatus at least partially disposed in the well bore wherein a first set of fluids are present therein; comparing the actual buoyed hookload to a calculated buoyed hookload of the apparatus, wherein the calculated buoyed hookload is based in part on the unbuoyed hookload of the apparatus, and the properties of a second set of fluids that are assumed to be present in the well bore; and determining at least one property of the first set of fluids based in part on the comparison of the actual buoyed hookload to the calculated buoyed hookload.

Abstract: A method of regulating downhole pressure using managed pressure drilling may include calculating an elasticity of a drill string during a drilling operation using a torque and drag model included in a managed pressure drilling (MPD) control system and calculating a surge pressure and a swab pressure acting on the drill string during the drilling operation using a hydraulics model included in the MPD control system. The surge and swab pressures may be based on movement of the drill string and in accordance with the elasticity of the drill string. The method may further include determining a set point pressure using a real-time hydraulics model and the torque and drag model, and operating a MPD choke system based on the set point pressure to regulate a predetermined downhole pressure at a predetermined location in a wellbore.

Abstract: Systems and methods for monitoring and characterizing fluids in a subterranean formation are provided. In one embodiment, a method for monitoring fluids in a well bore penetrating a subterranean formation is provided, the method comprising: determining an actual buoyed hookload of an apparatus at least partially disposed in the well bore wherein a first set of fluids are present therein; comparing the actual buoyed hookload to a calculated buoyed hookload of the apparatus, wherein the calculated buoyed hookload is based in part on the unbuoyed hookload of the apparatus, and the properties of a second set of fluids that are assumed to be present in the well bore; and determining at least one property of the first set of fluids based in part on the comparison of the actual buoyed hookload to the calculated buoyed hookload.

Abstract: Systems and methods for obtaining information about one or more fluids in a wellbore in a subterranean formation are disclosed herein. A fluid monitoring system comprises a fluid measurement device and a data system that receives a first and second set of data. A first set of data and second set of data may be obtained and compared to determine the location of one or more fluids in a wellbore in real time.

Abstract: A fluid monitoring system comprises a data acquisition and control interface and one or more fluid measurement devices communicatively coupled to the data acquisition and control interface. The one or more fluid measurement devices are configured to detect amounts of fluids pumped into or exiting the well bore during cementing. The data acquisition and control interface receives a first set of data comprising calculated volumes and/or pressures of a flow of one or more fluids exiting a model well bore over a predetermined period of time based in part on a heat of reaction produced by the curing of a cement composition, and a second set of data comprising volumes and/or pressures of a flow of one or more fluids pumped into or exiting the well bore from the one or more fluid measurement devices. The data acquisition and control interface uses the first and second sets of data received to determine one or more characteristics of the cement composition.

Abstract: The present disclosure includes systems and methods for expanded mud pulse telemetry. An example method includes measuring pressure proximate at least one of first and second pressure control modules along a drilling apparatus and telemetering the measured pressure to a surface controller. A command is transmitted from the surface controller to at least one of the first and second pressure control modules or one of first and second controllable flow restrictors via mud pulse telemetry while mud is not being pumped through a main standpipe.

Abstract: A method for modifying a return fluid in a wellbore comprises disposing at least one controllable flow restrictor along a drill string in the wellbore. At least one parameter of interest is determined at at least one location along an annulus in the wellbore. Controllably actuating the at least one flow restrictor to modify a local property of a return fluid in the annulus based at least in part on the measured parameter of interest.

Abstract: A well drilling method utilizing real time response to ahead of bit measurements. A well drilling method includes measuring a property of a portion of the earth prior to drilling a wellbore into the earth portion; and varying a drilling parameter in real time while drilling the wellbore, in response to measuring the property.

Abstract: A method of segregating flowable materials in conjunction with a subterranean well can include segregating flowable cement from a fluid by placing a flowable barrier substance between the cement and the fluid, and the barrier substance substantially preventing displacement of the cement by force of gravity through the barrier substance and into the fluid. Another method of segregating flowable materials can include flowing a barrier substance into a wellbore above a fluid already in the wellbore, and then flowing cement into the wellbore above the barrier substance. A system for use in conjunction with a subterranean well can include a flowable cement isolated from a fluid by a flowable barrier substance positioned between the cement and the fluid, whereby the barrier substance substantially prevents displacement of the cement by force of gravity through the barrier substance and into the fluid.