US4697426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Choke cooling waxy oil
Assignee: SHEEL WESTERN E&P Inc
•
Filing: 1986-05-29
•
Granted: 1987-10-06
•
Expires: 2006-05-29
Abstract
Abstract A stream of gas and waxy oil is cooled by a choke to form a wax/oil slurry, and the slurry is pipeline transported without wax deposition in the pipeline and/or to prevent melting of permafrost along the pipeline right of way.
Inventors
- 👤 William T. Knowles, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:38
CPC Classifications
F; F17; F17D; F17D1/00; F17D1/005; F17D1/08; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
80 words
A process for pipelining a waxy oil having a gas dissolved therein to essentially eliminate deposition of wax on the pipeline wall, comprising: forming a pressurized mixture of said waxy oil with a gas dissolved therein and an additional gas; effecting a sudden pressure drop of said mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and forming a slurry of wax particles and oil; and pipelining the slurry.
Claim 2
Dependent Claim
80 words
A process for pipelining a waxy oil having a gas dissolved therein to essentially eliminate deposition of wax on the pipeline wall, comprising: forming a pressurized mixture of said waxy oil with a gas dissolved therein and an additional gas; effecting a sudden pressure drop of said mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and forming a slurry of wax particles and oil; and pipelining the slurry.
Claim 3
Dependent Claim
12 words
The process of claim 1 including mixing the oil with the gas.
Claim 4
Dependent Claim
23 words
The process of claim 1 wherein the sudden pressure drop is effected by passing the mixture of oil and gas through a choke.
Claim 5
Dependent Claim
16 words
The process of claim 1 wherein the oil and/or gas are partially dehydrated prior to mixing.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein at least part of the gas is removed after forming the slurry.
Claim 7
Dependent Claim
21 words
The process of claim 5 wherein at least part of the removed gas is recycled to be mixed with the oil.
Claim 8
Dependent Claim
24 words
The process of claim 5 wherein at least part of the removed gas is reinjected into a formation from which the oil is produced.
Claim 9
Dependent Claim
24 words
The process of claim 5 wherein at least part of the removed gas is used as fuel at the site of the slurry-forming operation.
Claim 10
Dependent Claim
20 words
The process of claim 1 wherein methanol is added to the oil-gas mixture prior to effecting the sudden pressure drop.
Claim 11
Dependent Claim
21 words
The process of claim 1 wherein hydrate inhibitor is added to the oil/gas mixture prior to effecting the sudden pressure drop.
Claim 12
Dependent Claim
20 words
The process of claim 1 wherein antifreeze is added to the oil/gas mixture prior to effecting the sudden pressure drop.
Claim 13
Dependent Claim
12 words
The process of claim 1 wherein the slurry is pipelined through permafrost.
Claim 14
Dependent Claim
30 words
The process of claim 1 wherein a static mixer and high velocity in the piping upstream of the pressure drop location are included for the purpose of ensuring stable operations.
Claim 15
Dependent Claim
32 words
The process of claim 1 wherein a thermal break is installed between the pressure drop location and upstream piping to prevent heat transfer between the pressure drop location and the upstream piping.
Claim 16
Dependent Claim
17 words
The process of claim 1 wherein facilities upstream and downstream of the pressure drop location are insulated.
Claim 17
Dependent Claim
33 words
The process of claim 1 wherein some light ends remain in the oil after cooling and are transported with the oil to a pipeline destination and used as fuel for stabilizing the oil.
Claim 18
Dependent Claim
26 words
The process of claim 1 wherein after chilling and prior to entering the pipeline, the oil is stripped with an inert gas to remove light ends.
Claim 19
Dependent Claim
25 words
The process of claim 1 wherein after chilling, the oil and some of the gas are transported as a two-phase fluid to a pipeline destination.
Claim 20
Dependent Claim
26 words
The process of claim 1 wherein after chilling, the oil, wax and some of the gas are transported as a three-phase fluid to a pipeline destination.
Claim 21
Dependent Claim
31 words
The process of claim 1 wherein upstream of the pressure drop location, the oil and gas are cooled by conventional means to a temperature above the cloud point of the oil.
Claim 22
Dependent Claim
18 words
The process of claim 1 wherein ice particles formed in the chilling step are slurried with the oil.
Claim 23
Dependent Claim
20 words
The process of claim 1 wherein the pressure drop step is used as an integral part of process control strategy.
Claim 24
Dependent Claim
18 words
The process of claim 1 wherein addition of pour point depressant is used for modifying wax crystal size.
Claim 25
Dependent Claim
113 words
A process for providing a process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; effecting a sudden pressure drop of said mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and forming a slurry of wax particles and said waxy oil; pipelining the slurry; and removing at least part of the gas from the slurry and recycling said at least part of the removed gas to be mixed with the waxy oil to form said mixture of the waxy oil and the gas.
Claim 26
Dependent Claim
113 words
A process for providing a process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; effecting a sudden pressure drop of said mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and forming a slurry of wax particles and said waxy oil; pipelining the slurry; and removing at least part of the gas from the slurry and recycling said at least part of the removed gas to be mixed with the waxy oil to form said mixture of the waxy oil and the gas.
Claim 27
Dependent Claim
101 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; effecting a sudden pressure drop of said mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and forming a slurry of wax particles and said waxy oil; pipelining the slurry; and removing at least part of the gas from the slurry and reinjecting at least a part of the removed gas into a formation from which the waxy oil is produced.
Claim 28
Dependent Claim
101 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; effecting a sudden pressure drop of said mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and forming a slurry of wax particles and said waxy oil; pipelining the slurry; and removing at least part of the gas from the slurry and reinjecting at least a part of the removed gas into a formation from which the waxy oil is produced.
Claim 29
Dependent Claim
83 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; adding a hydrate inhibitor to said mixture of the waxy oil and the gas; effecting a sudden pressure drop of the mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and form a slurry of wax particles and oil; and pipelining the slurry.
Claim 30
Dependent Claim
83 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; adding a hydrate inhibitor to said mixture of the waxy oil and the gas; effecting a sudden pressure drop of the mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and form a slurry of wax particles and oil; and pipelining the slurry.
Claim 31
Dependent Claim
107 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; cooling the mixture of the waxy oil and the gas by heat exchange to a temperature just above the cloud point of the oil; adding a hydrate inhibitor to the mixture of the waxy oil and the gas; effecting a sudden pressure drop of the mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and form a slurry of wax particles and oil; and pipelining the slurry.
Claim 32
Dependent Claim
107 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a pressurized mixture of said waxy oil and a gas; cooling the mixture of the waxy oil and the gas by heat exchange to a temperature just above the cloud point of the oil; adding a hydrate inhibitor to the mixture of the waxy oil and the gas; effecting a sudden pressure drop of the mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and form a slurry of wax particles and oil; and pipelining the slurry.
Claim 33
Dependent Claim
83 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a mixture of said waxy oil and a gas; adding a pour point depressant to the mixture of the waxy oil and the gas; effecting a sudden pressure drop of the mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and form a slurry of wax particles and oil; and pipelining the slurry.
Claim 34
Dependent Claim
83 words
A process for pipelining a waxy oil to essentially eliminate deposition of wax on the pipeline wall, comprising: providing a mixture of said waxy oil and a gas; adding a pour point depressant to the mixture of the waxy oil and the gas; effecting a sudden pressure drop of the mixture of the waxy oil and the gas, thereby expanding a substantial portion of the gas to chill the oil and form a slurry of wax particles and oil; and pipelining the slurry.
References Cited (Backward Citations)
US25759A
Cited
US30281A
Cited
USRE25759E
Cited
US2352883A
Cited
US2303823A
Cited
GB768654A
Cited
GB768655A
Cited
US3027319A
Cited
US3350296A
Cited
US3429800A
Cited
US3454464A
Cited
US4141924A
Cited
US3773650A
Cited
US3846279A
Cited
US4013544A
Cited
US3910299A
Cited
USRE30281E
Cited
US3963795A
Cited
US4050742A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |