Downhole vibration monitoring of a drillstring
First Claim
1. Apparatus for monitoring vibration of a bottom hole assembly secured to the lower end of a drillstring used to drill a well, the apparatus comprising:
- 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 bottom hole assembly;
a computer mounted in the assembly and programmed to collect data from the accelerometer, digitally average and compute magnitude of the assembly acceleration; and
a non-volatile bulk storage memory connected to the computer;
means for storing collected data in the memory;
a buffer for temporarily storing collected data;
means for comparing the value of data stored in the buffer with the value of data stored in the memory;
means for replacing data in the memory with data in the buffer when the buffer data exceeds the level of the data in memory; and
means for comparing data stored in the buffer with a preset level.
1 Assignment
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Accused Products
Abstract
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.
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Citations
12 Claims
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1. Apparatus for monitoring vibration of a bottom hole assembly secured to the lower end of a drillstring used to drill a well, the apparatus comprising:
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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 bottom hole assembly; a computer mounted in the assembly and programmed to collect data from the accelerometer, digitally average and compute magnitude of the assembly acceleration; and a non-volatile bulk storage memory connected to the computer; means for storing collected data in the memory; a buffer for temporarily storing collected data; means for comparing the value of data stored in the buffer with the value of data stored in the memory; means for replacing data in the memory with data in the buffer when the buffer data exceeds the level of the data in memory; and means for comparing data stored in the buffer with a preset level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. Apparatus for monitoring vibration of a bottom hole assembly secured to the lower end of a drillstring used to drill a well, the apparatus comprising:
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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 bottom hole assembly; a computer mounted in the assembly and programmed to collect data from the accelerometer and compute magnitude of the assembly acceleration; means downhole for processing selected data in accordance with any or all of the following algorithms;
##EQU7## where A is the instantaneous value of acceleration for n, data points having a mean value of A, and means for selecting from the collected data a value which exceeds a present level. - View Dependent Claims (12)
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Specification