Patent US4745937A successfully refreshed from Google Patents.
US4745937A
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Process for restarting core flow with very viscous oils after a long standstill period
Assignee: Intevep SA
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Filing: 1987-11-02
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Granted: 1988-05-24
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Expires: 2007-11-02
Abstract
Abstract The present invention relates to a process for restarting core flow with viscous oil after a long standstill period. The process comprises initiating a flow of low viscosity fluid such as water into an inlet portion of a pipeline; gradually increasing the flow of the low viscosity fluid until a desired steady state condition is reached and initiating a flow of viscous oil into the inlet portion of the pipeline after the steady state condition has been reached.
Inventors
- 👤 Konstantin Zagustin
- 👤 Emilio Guevara
- 👤 Gustavo Nunez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:10
CPC Classifications
F; F15; F15D; F15D1/00; F15D1/02; F15D1/06; F17; F17D; F17D1/00; F17D1/08; F17D1/088; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
78 words
A process for restarting core flow of viscous oil within a pipe line after an interruption in said flow which comprises: initiating the flow of a low viscosity fluid into an inlet portion of said pipeline; gradually increasing the flow of said low viscosity fluid until a desired steady state condition is reached; and initiating the flow of said viscous oil into said inlet portion of said pipeline after the low viscosity fluid reached said steady state condition.
Claim 2
Dependent Claim
78 words
A process for restarting core flow of viscous oil within a pipe line after an interruption in said flow which comprises: initiating the flow of a low viscosity fluid into an inlet portion of said pipeline; gradually increasing the flow of said low viscosity fluid until a desired steady state condition is reached; and initiating the flow of said viscous oil into said inlet portion of said pipeline after the low viscosity fluid reached said steady state condition.
Claim 3
Dependent Claim
25 words
A Process as in claim 1 wherein said gradually increasing step comprises increasing the flow of said low viscosity fluid in a substantially linear manner.
Claim 4
Dependent Claim
89 words
A process as in claim 2 wherein said increasing step comprises increasing the flow of said low viscosity fluid at a rate in accordance with the equation Q=(Q.sub.max /T.sub.o)T (1) wherein Q=low viscosity fluid mass flow rate increase; Q max =maximum low viscosity fluid mass flow rate at the steady state condition; T o =time corresponding to the establishment of core-annular flow conditions; and T=elapsed time from restart; and T o can be obtained from T o =K T s 1/2 wherein T s =time of standstill; and K=constant.
Claim 5
Dependent Claim
36 words
A process as in claim 1 wherein said increasing step comprises increasing the flow of said low viscosity fluid until a critical velocity needed to form an annular flow of said low viscosity fluid is reached.
Claim 6
Dependent Claim
64 words
A process as in claim 1 which further comprises providing a pump for creating said flow of viscous oil into said pipeline and a variable speed motor for controlling the rate of discharge of said oil pump; said initiating step comprising starting up said oil pump; and gradually increasing the flow of said viscous oil into said pipeline by adjusting said variable speed motor.
Claim 7
Dependent Claim
46 words
A process as in claim 1 which further comprises: providing a flow bypass and a control valve for providing at least some of said viscous oil to said pipe line; and gradually increasing the flow of said viscous oil into said pipeline by adjusting said valve.
Claim 8
Dependent Claim
41 words
A process as in claim 1 which further comprises: said increasing step causing a peak pressure to be formed at said inlet portion; and activating natural surfactant by adding sodium silicate to said low viscosity fluid to minimize said peak pressure.
Claim 9
Dependent Claim
29 words
A process as in claim 7 wherein said low viscosity fluid comprises water and said adding step comprising adding less than about 0.04% of sodium silicate to said water.
Claim 10
Dependent Claim
44 words
A process as in claim 1 wherein said low viscosity fluid initiating step comprises providing a pump for creating said flow of low viscosity fluid into said pipeline and starting up said pump and said increasing step comprises increasing the discharge of said pump.
Claim 11
Dependent Claim
43 words
A process as in claim 1 wherein said increasing step comprises increasing the flow rate of said low viscosity fluid until a low viscosity fluid fraction and flow rate substantially equal to those existing in the pipeline prior to said interruption are reached.
Claim 12
Dependent Claim
44 words
A process as in claim 1 wherein the oil flow initiating step comprises initiating the flow of a viscous oil having a density in the range of from about 1.02 to about 0.96 grams per milliliter and a viscosity up to about 2,000,000 centipoises.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |