US4702758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Turbine cooling waxy oil
Assignee: Shell Western E and P Inc
•
Filing: 1986-05-29
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Granted: 1987-10-27
•
Expires: 2006-05-29
Abstract
Abstract A stream of gas and waxy oil is cooled by an expansion turbine 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
- 👤 Julia S. Geer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:42
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0068; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
81 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 oil and the gas through an expansion turbine, thereby expanding the gas and quickly cooling the oil to below its cloud point in the substantial absence of wax deposition and forming a slurry of wax particles and oil; and pipelining the slurry.
Claim 2
Dependent Claim
81 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 oil and the gas through an expansion turbine, thereby expanding the gas and quickly cooling the oil to below its cloud point in the substantial absence of wax deposition 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
20 words
The process of claim 1 wherein the turbine is utilized to convert energy from the fluid stream into mechanical work.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the work is utilized for on-site electricity generation.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein the work is utilized for air compression.
Claim 7
Dependent Claim
13 words
The process of claim 1 wherein the work is utilized for gas compression.
Claim 8
Dependent Claim
18 words
The process of claim 1 wherein at least part of the gas is removed after forming the slurry.
Claim 9
Dependent Claim
24 words
The process of claim 7 wherein at least part of the removed gas is reinjected into a formation from which the oil is produced.
Claim 10
Dependent Claim
24 words
The process of claim 7 wherein at least part of the removed gas is used as fuel at the site of the slurry-forming operation.
Claim 11
Dependent Claim
21 words
The process of claim 1 wherein at least part of the removed gas is recycled to be mixed with the oil.
Claim 12
Dependent Claim
18 words
The process of claim 1 wherein the oil and/or gas are at least partially dehydrated prior to mixing.
Claim 13
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 14
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 15
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 16
Dependent Claim
23 words
The process of claim 1 wherein a static mixer and high velocity in the piping upstream of the pressure drop location are included.
Claim 17
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 18
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 19
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 20
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 21
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 22
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 23
Dependent Claim
18 words
The process of claim 1 wherein ice particles formed in the chilling step are slurried with the oil.
Claim 24
Dependent Claim
15 words
The process of claim 1 wherein the pressure drop step is used for process control.
Claim 25
Dependent Claim
18 words
The process of claim 1 wherein addition of pour point depressant is used for modifying wax crystal size.
Claim 26
Dependent Claim
17 words
The process of claim 1 wherein turbine blades are heated to prevent wax deposits on the blades.
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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) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |