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US4852399A
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US
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Method for determining drilling conditions while drilling
Assignee: Anadrill Inc
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Filing: 1988-07-13
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Granted: 1989-08-01
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Expires: 2008-07-13
Abstract
Abstract Downhole torque and rate of penetration are utilized to develop indications of formations that are porous, argillaceous or tight. This information is useful as an aid in selecting drilling practices and drilling bits. The method separates bit effects from lithology effects when drilling with roller cone or PDC bits by utilizing surface and subsurface wellsite sensors to determine averaged values of real time penetration rate and downhole torque. Changes in bit torque are used to broadly classify the lithology into three categories: porous, argillaceous and tight formations while trends in bit torque and rate of penetration in shale are used to separate wear of the bit from changes in formation strength.
Inventors
- 👤 Ian G. Falconer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:26
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/003; E21B44/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
61 words
A method for monitoring the drilling process while drilling a borehole through subsurface formations with a drill bit, comprising the steps of: a. generating a signal indicative of the torque applied to the drill bit in the drilling process; and b. distinguishing between argillaceous, porous and tight formations and generating an indication thereof in response to said signal indicative of torque.
Claim 2
Independent Claim
61 words
A method for monitoring the drilling process while drilling a borehole through subsurface formations with a drill bit, comprising the steps of: a. generating a signal indicative of the torque applied to the drill bit in the drilling process; and b. distinguishing between argillaceous, porous and tight formations and generating an indication thereof in response to said signal indicative of torque.
Claim 3
Dependent Claim
39 words
The method as recited in claim 1 wherein said distinguishing step includes the steps of determining a reference value for said signal indicative of torque and performing a comparison between said signal indicative of torque and said reference value.
Claim 4
Dependent Claim
101 words
The method as recited in claim 2 wherein said distinguishing and signal generating steps include the steps of: a. establishing high and low limits around said reference value, b. generating a signal indicative of porous formations when said comparison indicates said signal indicative of torque is greater than said high limit, c. generating a signal indicative of tight formations when said comparison indicates said signal indicative of torque is less than said low limit; and d. generating a signal indicative of argillaceous formations when said comparison indicates said signal indicative of torque is between said low limit and said high limit.
Claim 5
Dependent Claim
27 words
The method as recited in claim 2 wherein said reference value is determined from signals indicative of torque determined while said drill bit is drilling argillaceous formations.
Claim 6
Dependent Claim
52 words
The method as recited in claim 1 wherein said signal indicative of torque is indicative of dimensionless torque defined by the following relationship: T.sub.D =12T/W*D where T is the downhole torque experienced by the drill bit, W is the weight placed on the bit and D is the diameter of the bit.
Claim 7
Dependent Claim
70 words
The method as recited in claim 1 wherein said signal indicative of torque is a signal indicative of drilling efficiency corrected for friction and normalized for changes in weight on bit according to the following relationship: E.sub.D.sbsb.n =[1-(1-E.sub.D)(W)]/W.sub.n where ED is the drilling efficiency of the bit, W is the weight placed on the bit and W n is the weight that is recommended to be placed on the bit.
Claim 8
Dependent Claim
71 words
The method as recited in claim 1 wherein said signal indicative of torque is a signal indicative of drilling efficiency, said method further including the steps of: a. generating an indication of the resistance to penetration of the formation by the drill bit; b. in response to said indication of penetration resistance and to said indication of drilling efficiency, identifying porous formations and tight formations in addition to said argillaceous formations.
Claim 9
Dependent Claim
48 words
The method as recited in claim 1 further including the steps of: a. generating an indication of the resistance to penetration of the formation by the drill bit; b. in response to said indication of penetration resistance and to said indication of torque, identifying occurrences of abnormal torque.
Claim 10
Dependent Claim
89 words
The method as recited in claim 7, wherein said step of identifying porous and tight formations includes the steps of: a. establishing a predetermined normal value of resistance to penetration of said formation by the drill bit; b. comparing said indication of penetration resistance to said predetermined normal value of penetration resistance; c. generating an indication of porous formation when said penetration resistance is smaller than said predetermined normal value; and d. generating an indication of tight formation when said penetration resistance is greater than said predetermined normal value.
Claim 11
Dependent Claim
126 words
The method as recited in claim 8, wherein said step of identifying occurrences of excess torque includes the steps of: a. establishing a predetermined normal value of resistance to penetration of said formation by the drill bit; b. establishing a predetermined normal value of said signal indicative of torque; c. comparing said signal indicative of torque with said predetermined normal value of said signal indicative of torque; d. comparing said indication of penetration resistance to said predetermined normal value of penetration resistance; e. generating an indication of abnormal torque when said penetration resistance is greater than or equal to said predetermined normal value of penetration resistance and when said signal indicative of torque is larger than said predetermined normal value of said signal indicative of torque.
Claim 12
Independent Claim
108 words
A method for monitoring the drilling process while drilling a borehole through subsurface formations with a drill bit, comprising the steps of: a. deriving at least one signal which characterizes the unworn bit's drilling characteristics in argillaceous formations; b. deriving at least one signal which characterizes the drilling of argillaceous formation as said subsurface formations are being drilled by said bit; c. determining when the bit is penetrating formations that do not drill like argillaceous formation; d. deriving a signal which characterizes the drilling of said formations that do not drill like argillaceous formations in response to one of said signals which characterize the drilling of argillaceous formations.
Claim 13
Independent Claim
108 words
A method for monitoring the drilling process while drilling a borehole through subsurface formations with a drill bit, comprising the steps of: a. deriving at least one signal which characterizes the unworn bit's drilling characteristics in argillaceous formations; b. deriving at least one signal which characterizes the drilling of argillaceous formation as said subsurface formations are being drilled by said bit; c. determining when the bit is penetrating formations that do not drill like argillaceous formation; d. deriving a signal which characterizes the drilling of said formations that do not drill like argillaceous formations in response to one of said signals which characterize the drilling of argillaceous formations.
Claim 14
Dependent Claim
36 words
The method as recited in claim 11 wherein said signal which characterizes the drilling of said formations that do not drill like argillaceous formations is a signal indicative of the resistance to penetration of the formation.
Claim 15
Dependent Claim
35 words
The method as recited in claim 11 wherein said signal which characterizes the drilling of said formations that do not drill like argillaceous formations is a signal indicative of the drilling efficiency of the bit.
Claim 16
Dependent Claim
67 words
The method as recited in claim 11 wherein said step of determining when the bit is penetrating formations that do not drill like argillaceous formations includes the steps of: a. generating a signal indicative of the torque applied to the drill bit in the drilling process; and b. distinguishing between argillaceous and non-argillaceous formations and generating an indication thereof in response to said signal indicative or torque.
References Cited (Backward Citations)
US28436A
Cited
USRE21297E
Cited
US21297A
Cited
US2372576A
Cited
US2669871A
Cited
US3368400A
Cited
US3541852A
Cited
US3581564A
Cited
USRE28436E
Cited
US3898880A
Cited
US3774445A
Cited
US3782190A
Cited
US3916684A
Cited
US4064749A
Cited
US4359898A
Cited
US4685329A
Cited
US4697650A
Cited
US4627276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-31 | 1993-01-30 | 1993-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-31 | 1997-01-30 | 1997-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-31 | 2001-01-30 | 2001-08-01 | $7700.00 | Window Closed / Lapsed |