摘要:
A system for communicating between a first location and a second location comprises a jointed tubular string having a first section and a second section connected at a connection joint, with the tubular string having a fluid in an internal passage thereof. A first acoustic transducer is mounted in the internal passage of the first section proximate the connection joint, and a second acoustic transducer is mounted in the internal passage of the second section proximate the connection joint. A signal transmitted from the first location to the second location is transmitted across the connection joint as an acoustic signal in the fluid from the first acoustic transducer to the second acoustic transducer.
摘要:
A formation pressure testing while drilling device on a bottomhole assembly makes measurements of fluid pressure during drilling of a borehole. Based on the pressure measurements, drilling direction can be altered to maintain the wellbore in a desired relation to a fluid contact. Acoustic transmitters and/or receivers on the bottomhole assembly can provide additional information about bed boundaries, faults and gas-water contacts.
摘要:
A system for communicating between a first location and a second location comprises a jointed tubular string having a first section and a second section connected at a connection joint, with the tubular string having a fluid in an internal passage thereof. A first acoustic transducer is mounted in the internal passage of the first section proximate the connection joint, and a second acoustic transducer is mounted in the internal passage of the second section proximate the connection joint. A signal transmitted from the first location to the second location is transmitted across the connection joint as an acoustic signal in the fluid from the first acoustic transducer to the second acoustic transducer.
摘要:
A system for communicating between a first location and a second location comprises a jointed tubular string having a first section and a second section connected at a connection joint, with the tubular string having a fluid in an internal passage thereof. A first acoustic transducer is mounted in the internal passage of the first section proximate the connection joint, and a second acoustic transducer is mounted in the internal passage of the second section proximate the connection joint. A signal transmitted from the first location to the second location is transmitted across the connection joint as an acoustic signal in the fluid from the first acoustic transducer to the second acoustic transducer.
摘要:
The present disclosure provides a downhole tool that includes a magnetometer and a nuclear magnetic resonance (NMR) sensor. One or more compensating magnets are provided on the tool to cancel or offset the effect of the magnetic field of the magnets of the NMR sensor on the magnetometer measurements made during drilling of a wellbore. The compensating magnets may have the same magnetic field characteristics as the sensor magnets and may be made of the same material.
摘要:
An acoustic transducer on a downhole tool sends an acoustic wave through a sensor plate in contact with drilling fluid. Vibrations of the sensor plate are indicative of the impedance of the borehole plate that may be associated with gas influx. A processor analyzes the vibrations and uses an estimated Q of the vibrations to determine gas influx. 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:
A method and apparatus provide a time-dependent calibration to essentially eliminate pipe effect in pulse-induction logging while drilling. Use of two receivers to provide calibration and measurement information allows determination of formation properties in a downhole environment while eliminating the effect of tool effects.
摘要:
Disclosed systems and methods provide automated log quality monitoring, thereby enabling fast, on-site determination of log quality by logging engineers as well as re-assurance to interpreters faced with geologically-improbable features in the logs. Such uses can provide early detection of logging issues, increase confidence in acquired logs, reduce unnecessary duplication of effort, and improve the reputation of the logging company. In at least some embodiments, log monitoring software applies a comparison function to axially-spaced (and/or azimuthally-spaced) sensors. The comparison function can be, inter alia, cross-correlation, mutual information, mean-square error, and ratio image uniformity, each of which can be determined as a function of a sliding window position to indicate regions wherein the log quality falls below a threshold value. It is not necessary for the log sensors to be of the same type, e.g., resistivity image sensors.
摘要:
In a resistivity log, a curve is obtained showing the values of resistivity where adjacent beds impact the measured resistivity. The curve as a function of well depth is first converted into a rectangularized curve so that the interfaces of the adjacent strata are located, and by a suitable number of iterations, a correction factor is applied. The corrected rectangular log is obtained with a correction coefficient computed at each depth. For each computation, the impact of all the strata within a specified depth window is considered, while strata beyond that window are simplified by representing the strata beyond the window with single equivalent bed values to reduce the number of computations required. This then provides a resistivity log which is substantially free of shoulder bed effect.
摘要:
High resolution induction logs (28) are obtained through borehole casing (15) by magnetically saturating the casing (15), logging with a tool (10) having different transmitter (35a, 35b)-to-receiver (40) coil spacings, and determining the formation (30) conductivities as a function of the coil spacings, coil frequency, and phase difference between the signals at these spacings. The logging is preferably done at an intermediate frequency which gives good resolution but is little affected by the saturated casing.