摘要:
A method and apparatus for encoding and synchronizing and sequencing pulse encoded data in a pulse telemetry system. The time intervals between successive pulses in a pulse train are representative of the magnitude of the data parameters. Redundant pulses are included in the pulse trains at predetermined time locations with respect to the pulses so as to enhance the ability to recognize or distinguish data pulses over noise signals. Synchronization pulses are employed to enable identification of the particular data parameters even though one or more of the data pulses is obscured by noise. The sequence of the production of the pulse code signals is continuously monitored to enable the telemetering system to be activated promptly after a shutdown at the place in the train of data where it would be if the shutdown had not occurred.
摘要:
A filter for use in filtering noise from cyclical signals having a data component and a noise component in which a predetermined number of the cyclical signals are averaged to produce an average signature signal. The average signature signal is updated each cycle to produce a current updated average signature signal, and the current cyclical signals and the current updated average signals are subtracted from one another to remove the noise component and produce a residual signal which contains the data component. The time frames of the current cyclical signals and the current updated average signals are adjusted to be equal so as to enable point by point subtraction.As an additional feature, the updating of the average pump signature combines a portion of the last average pump signature with a portion of the last residual signal.
摘要:
A replaceable insulating sleeve is disposed around the lower end of a drill string used in drilling a well. The sleeve is restrained from rotating relative to the drill string, but can be released and quickly slipped off the drill string in the field to permit rapid replacement if damaged, or if alternate equipment is required. The sleeve carries sensing means for measuring a characteristic of formations penetrated by the well. Anchor means on the sensing means prevents it from rotating relative to the sleeve.
摘要:
In an apparatus for measuring equipment depth in a well, the movement of wire rope used to raise and lower the equipment is measured by proximity sensors located adjacent the wire rope and spaced along the direction of movement of the wire rope. The signals from the proximity sensors caused by the spiral windings of the wire rope are employed to determine the length and direction of movement of the wire rope. The invention may be employed to measure movement of wire rope in other applications, such as in elevators or with cages in mine shafts that are supported by wire rope.
摘要:
Apparatus for sending pressure pulses through drilling fluid in a drill string in a well bore includes an assembly adapted to be lowered from the surface through the drill string to a position adjacent the lower end of the drill string. The external dimension of the assembly is substantially less than that of the internal diameter of the drill string, so there is always a substantial clearance between the assembly exterior and the drill string interior to permit a substantial flow of drilling fluid down the drill string, past the assembly, through a drill bit, and into an annular space between the drill string exterior and the well bore. The assembly includes an internal bore to permit drilling fluid to flow through the assembly. Means are provided for intermittently restricting flow of drilling fluid through the assembly bore to send the pressure pulses to the surface in response to the magnitude of a downhole condition to be measured. The assembly includes means to permit it to be retrieved by a wire line from the surface and without removing the drill string from the well bore.
摘要:
A replaceable insulating sleeve is disposed around the lower end of a drill string used in drilling a well. The sleeve is restrained from rotating relative to the drill string, but can be released and quickly slipped off the drill string in the field to permit rapid replacement if damaged, or if alternate equipment is required. The sleeve carries sensing means for measuring a characteristic of formations penetrated by the well. Anchor means on the sensing means prevents it from rotating relative to the sleeve.
摘要:
A replaceable insulating sleeve is disposed around the lower end of a drill string used in drilling a well. The sleeve is restrained from rotating relative to the drill string, but can be released and quickly slipped off the drill string in the field to permit rapid replacement if damaged, or if alternate equipment is required. The sleeve carries sensing means for measuring a characteristic of formations penetrated by the well.
摘要:
The accuracy of well logging data transmitted from a downhole location to the surface of the earth is verified by generating the data at the downhole location, storing the data in a subsurface assembly in the well, transmitting signals corresponding to the data to the surface through a first transmission system while keeping the data stored in the subsurface assembly, and recording the signals transmitted to the surface through the first transmission system. Thereafter, the subsurface assembly is transferred to the surface, and signals corresponding to the stored data are transmitted through a second transmission system from the assembly to an electronic processing system. The signals transmitted through the second transmission system are then compared with the signals transmitted through the first system.To increase the effective transmission rate of data from the downhole location to the surface, a first set of signals corresponding to the magnitude of a downhole condition as a function of time during a discrete time interval are generated and transmitted through a first transmission system to computer means at the downhole location. The first set of signals are analyzed in the computer to determine properties of the function selected from the group consisting of mean value, positive and negative peak values, standard deviation value, and fundamental and harmonic frequencies and amplitudes. A second set of signals corresponding to the selected values are generated and transmitted to the surface through a second transmission system.
摘要:
Apparatus for monitoring vibration of a bottom hole assembly used to drill a well includes at least one accelerometer mounted in the bottom hole assembly to generate data in the form of electrical signals corresponding to the acceleration experienced by the assembly. The computer in the assembly is programmed to collect data from the accelerometer and compute magnitude of the assembly acceleration. Means are provided for selecting from the collected data a value which exceeds a preset level. In one form, when the collected data has a value above a preset level, an alarm signal is sent to the surface so corrective measures can be taken to prevent damage to downhole equipment.
摘要:
Apparatus for sending pressure pulses through drilling fluid in a drill string in a well bore includes an assembly adapted to be lowered from the surface through the drill string to a position adjacent the lower end of the drill string. The external dimension of the assembly is substantially less than that of the internal diameter of the drill string, so there is always a substantial clearance between the assembly exterior and the drill string interior to permit a substantial flow of drilling fluid down the drill string, past the assembly, through a drill bit, and into an annular space between the drill string exterior and the well bore. The assembly includes an internal bore to permit drilling fluid to flow through the assembly. Means are provided for intermittently restricting flow of drilling fluid through the assembly bore to send the pressure pulses to the surface in response to the magnitude of a downhole condition to be measured. The assembly includes means to permit it to be retrieved by a wire line from the surface and without removing the drill string from the well bore.