摘要:
Methods and control systems are provided for a wellbore drilling system having an active differential pressure device (APD device) in fluid communication with a returning fluid. The APD Device creates a differential pressure across the device, which reduces the pressure below or downhole of the device. In embodiments, a control unit controls the APD Device in real time via a data transmission system. In one arrangement, the data transmission system includes data links formed by conductors associated with the drill string. The conductors, which may include electrical wires and/or fiber optic bundles, couple the control unit to the APD Device and other downhole tools such as sensors. In other arrangements, the data link can include data transmission stations that use acoustic, EM, and/or RF signals to transfer data. In still other embodiments, a mud pulse telemetry system can be used in transfer data and command signals.
摘要:
An active differential pressure device (APD device) in fluid communication with a returning fluid creates a differential pressure across the device, which controls pressure below the APD Device. In embodiments, a control unit controls the APD Device to provide a selected pressure differential at a wellbore bottom, adjacent a casing shoe, in an intermediate wellbore location, or in a casing. In one arrangement, the control system is pre-set at the surface such that the APD Device provides a substantially constant pressure differential. In other arrangements, the control system adjusts an operating parameter of the APD Device to provide a desired pressure differential in response to one or more measured parameters. Devices such as an adjustable bypass can be used to control the APD Device. In other embodiments, one or more flow control devices coupled to the return fluid reduce the effective pressure differential provided by the APD Device.
摘要:
An APD Device provides a pressure differential in a wellbore to control dynamic pressure loss while drilling fluid is continuously circulated in the wellbore. A continuous circulation system circulates fluid both during drilling of the wellbore and when the drilling is stopped. Operating the APD Device allows wellbore pressure control during continuous circulation without substantially changing density of the fluid. The APD Device can maintain wellbore pressure below the combined pressure caused by weight of the fluid and pressure losses created due to circulation of the fluid in the wellbore, maintain the wellbore at or near a balanced pressure condition, maintain the wellbore at an underbalanced condition, reduce the swab effect in the wellbore, and/or reduce the surge effect in the wellbore. A flow restriction device that creates a backpressure in the wellbore annulus provides surface control of wellbore pressure.
摘要:
A device and system for improving efficiency of subterranean cutting elements uses a controlled oscillation super imposed on steady drill bit rotation to maintain a selected rock fracture level. In one aspect, a selected oscillation is applied to the cutting element so that at least some of the stress energy stored in an earthen formation is maintained after fracture of the rock is initiated. Thus, this maintained stress energy can thereafter be used for further crack propagation. In one embodiment, an oscillation device positioned adjacent to the drill bit provides the oscillation. A control unit can be used to operate the oscillation device at a selected oscillation. In one arrangement, the control unit performs a frequency sweep to determine an oscillation that optimizes the cutting action of the drill bit and configures the oscillation device accordingly. One or more sensors connected to the control unit measure parameters used in this determination.
摘要:
A device and system for improving efficiency of subterranean cutting elements uses a controlled oscillation super imposed on steady drill bit rotation to maintain a selected rock fracture level. In one aspect, a selected oscillation is applied to the cutting element so that at least some of the stress energy stored in an earthen formation is maintained after fracture of the rock is initiated. Thus, this maintained stress energy can thereafter be used for further crack propagation. In one embodiment, an oscillation device positioned adjacent to the drill bit provides the oscillation. A control unit can be used to operate the oscillation device at a selected oscillation. In one arrangement, the control unit performs a frequency sweep to determine an oscillation that optimizes the cutting action of the drill bit and configures the oscillation device accordingly. One or more sensors connected to the control unit measure parameters used in this determination.
摘要:
An apparatus and method for reducing temperature along a bottomhole assembly during a drilling operation is provided. In one aspect the bottomhole temperature may be reduced by drilling a borehole using a drill string having a bottomhole assembly at an end thereof, circulating a fluid through the drill string and an annulus between the drill string and the borehole, diverting a selected portion of the fluid from the drill string into the annulus at a selected location above the drill bit to reduce pressure drop across at least a portion of the bottomhole assembly to reduce temperature of the bottomhole assembly during the drilling operation.
摘要:
An apparatus and method for reducing temperature along a bottomhole assembly during a drilling operation is provided. In one aspect the bottomhole temperature may be reduced by drilling a borehole using a drill string having a bottomhole assembly at an end thereof, circulating a fluid through the drill string and an annulus between the drill string and the borehole, diverting a selected portion of the fluid from the drill string into the annulus at a selected location above the drill bit to reduce pressure drop across at least a portion of the bottomhole assembly to reduce temperature of the bottomhole assembly during the drilling operation.
摘要:
Gas hydrates, particularly natural gas hydrates e.g. methane hydrates, may be formed and controlled within conduits and vessels by imparting energy to gas and water, for instance using agitation or vibration. The systems and methods allow for improved flow characteristics for fluids containing the gases, e.g. hydrocarbon fluids being transported, and for improved overall efficiencies. The gas and water within a gas flow path may be perturbed or agitated to initiate formation of relatively small hydrate particles. The hydrate particles continue to form as long as energy is imparted and water and hydrate guest molecules are available. High amplitude agitation of the gas and water will repeatedly break up agglomerated hydrate particles that form and encourage the formation of more and smaller particles. As more hydrate forms in this manner, less and less free water may be available proximate the gas and water contact.
摘要:
Fluid systems may contain elements to provide changes in bulk fluid density in response to various environmental conditions. One environmental driver to the variable density is pressure; other environmental drivers include, but are not limited to, temperature or changes in chemistry. The variable density of the fluid is beneficial for controlling sub-surface pressures within desirable pore pressure and fracture gradient envelopes. The variability of fluid density permits construction and operation of a wellbore with much longer hole sections than when using conventional single gradient fluids.
摘要:
A method for reducing temperature of a bottomhole assembly during a drilling operation is disclosed, that, in one aspect, may include: drilling a borehole using a drillstring including a bottomhole assembly by circulating a fluid through the drillstring and an annulus between the drillstring and the borehole, pausing drilling, continuing circulating the fluid through the dill string and the annulus. The method further includes diverting a portion of the fluid from the drillstring into the annulus at a selected location above the drill bit to reduce temperature of the bottomhole assembly.