US3595075A
Expired / Lapsed
US
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Method and apparatus for sensing downhole well conditions in a wellbore
Assignee: Warren Automatic Tool Co
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Filing: 1969-11-10
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Granted: 1971-07-27
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Expires: 1989-11-10
Abstract
Abstract A method and apparatus for sensing downhole well conditions in a wellbore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down the well. The apparatus includes a pressure transmitter for sensing the circulating pressure of input drilling fluid being circulated down the well and generating a first signal representative thereof. It could also include means in the form of a differential pressure transmitter for sensing a pressure drop of the drilling fluid along a portion of the conduit means and generating a second signal representative thereof. Readout means in the form of dual concentric pressure gauges are provided for reading out a change between the signals as an indication of a change in downhole well conditions, such as loss of drilling fluids or incursion of formation fluids into the well.
Inventors
- 👤 Ethell J Dower
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:20
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/08; E21B47/00; E21B47/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
142 words
In a method for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination of steps comprising: sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; sensing drilling fluid pressure at two points along said conduit means with one of said points being upstream with respect to the other of said points; comparing the pressures at said points and generating a second signal representative of the difference therebetween; multiplying said second signal by a factor such that said first and second signals are of substantially the same magnitude during normal operations; and monitoring said signals to detect a change therebetween as an indication of a change in down hole well condition.
Claim 2
Dependent Claim
142 words
In a method for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination of steps comprising: sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; sensing drilling fluid pressure at two points along said conduit means with one of said points being upstream with respect to the other of said points; comparing the pressures at said points and generating a second signal representative of the difference therebetween; multiplying said second signal by a factor such that said first and second signals are of substantially the same magnitude during normal operations; and monitoring said signals to detect a change therebetween as an indication of a change in down hole well condition.
Claim 3
Dependent Claim
140 words
In a method for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination of steps comprising: sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; passing at least a portion of said drilling fluid through a flow restriction in said conduit means; sensing drilling fluid pressure at two points along said conduit means with one of said points being upstream and the other of said points being downstream from said flow restriction; comparing the pressures at said points and generating a second signal representative of the difference therebetween; and, monitoring said signals to detect a change therebetween as an indication of a change in down hole well conditions.
Claim 4
Dependent Claim
140 words
In a method for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination of steps comprising: sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; passing at least a portion of said drilling fluid through a flow restriction in said conduit means; sensing drilling fluid pressure at two points along said conduit means with one of said points being upstream and the other of said points being downstream from said flow restriction; comparing the pressures at said points and generating a second signal representative of the difference therebetween; and, monitoring said signals to detect a change therebetween as an indication of a change in down hole well conditions.
Claim 5
Dependent Claim
44 words
The invention as claimed in claim 2 wherein: said flow restriction is varied to thereby cause said first and second signals to be substantially of the same magnitude during normal operations, whereby a difference between said first and second signals indicates an abnormal condition.
Claim 6
Dependent Claim
96 words
In a method for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination of steps comprising: sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; sensing the pressure drop of said drilling fluid along a portion of said conduit means and generating a second signal representative thereof; and, comparing said first and second signals and generating a third signal representative of any change therebetween.
Claim 7
Dependent Claim
96 words
In a method for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination of steps comprising: sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; sensing the pressure drop of said drilling fluid along a portion of said conduit means and generating a second signal representative thereof; and, comparing said first and second signals and generating a third signal representative of any change therebetween.
Claim 8
Dependent Claim
146 words
In apparatus for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination comprising: MEANS for sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; means for sensing drilling fluid pressure at two points along said conduit means, with one of said points being upstream with respect to the other of said points; means for comparing the pressures at said points and generating a second signal representative of the difference therebetween; means for multiplying said second signal to increase the value thereof relative to said first signal; and, readout means for reading out a change between said first signal and said multiplied second signal as an indication of a change in down hole well conditions.
Claim 9
Dependent Claim
146 words
In apparatus for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination comprising: MEANS for sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; means for sensing drilling fluid pressure at two points along said conduit means, with one of said points being upstream with respect to the other of said points; means for comparing the pressures at said points and generating a second signal representative of the difference therebetween; means for multiplying said second signal to increase the value thereof relative to said first signal; and, readout means for reading out a change between said first signal and said multiplied second signal as an indication of a change in down hole well conditions.
Claim 10
Dependent Claim
149 words
In apparatus for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination comprising: means for sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; means for sensing drilling fluid pressure at two points along said conduit means, with one of said points being upstream with respect to the other of said points; means for comparing the pressures at said points and generating a second signal representative of the difference therebetween; means for comparing said first and second signals and generating a third signal representative of any change therebetween: and, readout means connected to receive said third signal for reading out a change in said third signal as an indication of a change in down hole well conditions.
Claim 11
Dependent Claim
149 words
In apparatus for sensing down hole well conditions in a well bore having a drill string suspended therein and pump means and conduit means for circulating drilling fluid down said well, the combination comprising: means for sensing the circulating pressure of input drilling fluid being circulated down said well and generating a first signal representative thereof; means for sensing drilling fluid pressure at two points along said conduit means, with one of said points being upstream with respect to the other of said points; means for comparing the pressures at said points and generating a second signal representative of the difference therebetween; means for comparing said first and second signals and generating a third signal representative of any change therebetween: and, readout means connected to receive said third signal for reading out a change in said third signal as an indication of a change in down hole well conditions.
References Cited (Backward Citations)
US2776817A
Cited
US3504537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |