摘要:
An electromagnetic telemetry repeater. At least some of the illustrative embodiments are methods comprising inducing an electrical signal along a metallic tubular (the electrical signal carrying the information and the inducing within a borehole beneath the ocean floor), sensing an electric field proximate to the ocean floor, sensing a magnetic field proximate to the ocean floor, recreating the information using one sensed field as indicative of the information and the other sensed field as indicative of the noise, and sending the information toward the ocean surface.
摘要:
An apparatus for determining the concentration of a conductive fluid present in a fluid filled bore hole is described. Such apparatus are known as water hold-up meters and are frequently used in oil, gas and water filled bore holes. In bore hole applications, data bandwidth between a down hole device and the surface can be limited, while determining water hold-up based on down hole measurements can be data intensive. A technique is proposed for calculating the water hold up that requires less data to be transmitted between the down hole device and the surface.
摘要:
Adsorbed gas in a formation may be estimated. Nuclear magnetic resonance (NMR) data for a subsurface geological formation is obtained, and at least a portion of the NMR data is corrected to produce corrected NMR data. A NMR-based estimate of formation porosity is determined using the corrected NMR data. Dielectric permittivity data for the subsurface geological formation is obtained, and a dielectric permittivity-based estimate of the formation water-filled porosity is determined using the dielectric permittivity data. A gas volume is determined using the determined NMR-based estimate of the formation porosity and the determined dielectric permittivity-based estimate of the formation water-filled porosity. The gas volume may be determined by subtracting the determined dielectric permittivity-based estimate of the formation water-filled porosity from the determined NMR-based estimate of the formation porosity. The gas volume per unit volume of the formation may be determined using an equation of state.
摘要:
Apparatus and methods for downhole information storage and transmission are disclosed herein. An example method disclosed herein includes losslessly compressing at least a portion of information received from a portion of a downhole tool disposed in a wellbore. The information is compressed via a processor disposed on the downhole tool and communicatively coupled to the portion of the downhole tool. The example method further includes transmitting at least a portion of the compressed information to a receiver disposed at or near a surface of Earth.
摘要:
Percolation theory is applied to establish a connection between magnetization decay of nuclear magnetic resonance (NMR) measurements and residual carbon dioxide saturation (Scr). As a result, estimations of Scr are obtained through use of an NMR tool in a formation and appropriate processing. Data may be displayed as a log.
摘要:
A method of processing downhole measurement data includes: receiving formation measurement data generated by a downhole tool during a logging-while drilling operation over a selected time period; receiving a measured depth corresponding to the selected time period based on data taken at a surface location; receiving tool rotation data generated by measurements of a rotational rate of the downhole tool taken by a downhole sensor during the selected time period; calculating a new depth of the tool as a function of time over the selected time period based on a relationship between the tool rotation data and the measured depth; and correcting an original depth of the measurement data with the new depth.
摘要:
A rotary coupler includes a first member having an internal surface, a first inductor positioned on the internal surface, a second member, and a second inductor carried on a portion of the second member and positioned internal of the first inductor, wherein one of the inductors rotates relative to the other inductor.
摘要:
A method and system for conducting a seismic survey by lowering a string of intelligent clampable sensor pods with 3-C sensors into a borehole. The string of pods is serially interconnected by a cable having a conductor pair which provides both power and data connectivity. The uppermost sensor pod is connected to a downhole telemetry and control module. The cables and pods use connectors to allow assembly, customization, repair, and disassembly on site. Each pod has an upper and a lower connector, a processor, and memory which is coupled to both the upper and the lower connectors. Each pod is capable of simultaneous and independent serial communications at each connector with the memory. The telemetry and control module is designed to query the pods to determine the system configuration. The telemetry and control module then simultaneously triggers all pods to acquire data, the pods storing the collected data locally in the memory. After data collection, the controller simultaneously signals the pods to immediately transfer data serially from the local memory to the next higher adjacent pod and receive data, if any, from the lower adjacent pod, if any, storing the received data in memory. The first data transferred from each pod is that data collected by its local sensors. Subsequent data originates from lower pods and is simply passed up the string of pods to the telemetry and control module. In other words, the pods communicate in a bucket brigade fashion.
摘要:
A combination of a shallow-reading and a deep-reading, azimuthally sensitive, multiple propagation devices is used for providing depth images the earth formation with different depth of investigation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
摘要:
An oscillating shear valve system for generating pressure fluctuations in a flowing drilling fluid comprising a stationary stator and an oscillating rotor, both with axial flow passages. The rotor oscillates in close proximity to the stator, at least partially blocking the flow through the stator and generating oscillating pressure pulses. The rotor passes through two zero speed positions during each cycle, facilitating rapid changes in signal phase, frequency, and/or amplitude facilitating enhanced, multivalent data encoding. The rotor is driven by a motorized gear drive. In one embodiment, a torsional spring is attached to the motor and the resulting spring mass system is designed to be near resonance at the desired pulse frequency. The system enables the use of multivalent encoding schemes for increasing data rates.