Abstract: Surface seismic sources are used to simulate crosswell data between the two wells, and, using surface receivers, reflection seismic data are obtained over the region between the two wells. Reflection data are preferably obtained from reflectors both above and below the reservoir. Tomographic analysis of the simulated crosswell and reflection data gives a model of the reservoir. Changes in the model are indicative of reservoir fluid changes, pressure changes, or compaction.

Abstract: One or more autonomous devices are deployed in the well to provide a moveable sensor source or obstruction for coupling a tube wave seismic signal into the formation adjacent the well bore. The autonomous devices move in the well and provide moveable obstructions or discontinuities which couple tube waves existing in the well bore or production tubing into the formation adjacent the well bore. Wellbore tube wave energy is converted to body wave energy at minor borehole obstructions or irregularities that become sources of seismic energy. A well bore may contain a plurality of minor obstructions or discontinuities. Each obstruction or discontinuity position along the borehole has an associated unique waveform source coda that may be measured for processing the wavefield radiated into the earth formation surrounding the well bore. A plurality of sensors detects the radiated seismic energy after the seismic energy has transited intervening earth formations.

Abstract: A wellbore drilling system has an umbilical that carries a drill bit in a wellbore. Drilling fluid pumped into the umbilical discharges at the drill bit bottom and returns through an annulus between the umbilical and the wellbore carrying entrained drill cuttings. An active differential pressure device (APD device), such as a jet pump, turbine or centrifugal pump, in fluid communication with the returning fluid creates a differential pressure across the device, which alters the pressure below or downhole of the device. The APD device can be driven by a positive displacement motor, a turbine, an electric motor, or a hydraulic motor. A controller controls the operation of the APD device in response to programmed instructions and/or one or more parameters of interest detected by one or more sensors. A preferred system is a closed loop system that maintains the wellbore at under-balance condition, at-balance condition or over-balance condition.

Abstract: A drilling system for drilling subsea wellbores includes a tubing-conveyed drill bit that passes through a subsea wellhead. Surface supplied drilling fluid flows through the tubing, discharges at the drill bit, returns to the wellhead through a wellbore annulus, and flows to the surface via a riser extending from the wellhead. A flow restriction device positioned in the riser restricts the flow of the returning fluid while an active fluid device controllably discharges fluid from a location below to just above the flow restriction device in the riser, thereby controlling bottomhole pressure and equivalent circulating density (“ECD”). Alternatively, the fluid is discharged into a separate return line thereby providing dual gradient drilling while controlling bottomhole pressure and ECD. A controller controls the energy and thus the speed of the pump in response to downhole measurement(s) to maintain the ECD at a predetermined value or within a predetermined range.

Abstract: This invention relates to flowable devices and methods of utilizing such flowable devices in wellbores to provide communicate between surface and downhole instruments, among downhole devices, establish a communication network in the wellbore, act as sensors, and act as power transfer devices. The flowable devices are adapted to move with a fluid flowing in the wellbore. The flowable device may be memory device or a device that can provide a measure of a parameter of interest or act as a power transfer device. The flowable devices are introduced into the flow of a fluid flowing in the wellbore. The fluid moves the device in the wellbore. If the device is a data exchange device, it may be channeled in a manner that enables a device in the wellbore to interact with the memory device, which may include retrieving information from the flowable device and/or recording information on the flowable device. The sensor in a flowable device can take a variety of measurement(s) in the wellbore.

Abstract: This invention relates to flowable devices and methods of utilizing such flowable devices in wellbores to provide communicate between surface and downhole instruments, among downhole devices, establish a communication network in the wellbore, act as sensors, and act as power transfer devices. The flowable devices are adapted to move with a fluid flowing in the wellbore. The flowable device may be memory device or a device that can provide a measure of a parameter of interest or act as a power transfer device. The flowable devices are introduced into the flow of a fluid flowing in the wellbore. The fluid moves the device in the wellbore. If the device is a data exchange device, it may be channeled in a manner that enables a device in the wellbore to interact with the memory device, which may include retrieving information from the flowable device and/or recording information on the flowable device. The sensor in a flowable device can take a variety of measurement(s) in the wellbore.

Abstract: One or more autonomous devices are deployed in the well to provide a moveable sensor source or obstruction for coupling a tube wave seismic signal into the formation adjacent the well bore. The autonomous devices move in the well and provide moveable obstructions or discontinuities which couple tube waves existing in the well bore or production tubing into the formation adjacent the well bore. Wellbore tube wave energy is converted to body wave energy at minor borehole obstructions or irregularities that become sources of seismic energy. A well bore may contain a plurality of minor obstructions or discontinuities. Each obstruction or discontinuity position along the borehole has an associated unique waveform source coda that may be measured for processing the wavefield radiated into the earth formation surrounding the well bore. A plurality of sensors detects the radiated seismic energy after the seismic energy has transited intervening earth formations.