US4416703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for removing debris from pipelines
Assignee: Shell USA Inc
•
Filing: 1981-11-20
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Granted: 1983-11-22
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Expires: 2001-11-20
Abstract
Abstract To remove particulate debris from a pipeline, a plug train including at least one gel plug having debris entraining characteristics and at least one pseudoplastic plug is passed through a pipeline and the debris is collected by the gel plug. The gel plug is pushed through the pipeline with a scraper which in turn may be pushed by liquid or gas pressure.
Inventors
- 👤 Paul R. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:36
CPC Classifications
B; B08; B08B; B08B9/00; B08B9/02; B08B9/027; B08B9/04; B08B9/053; B08B9/055; B08B9/0555
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
150 words
A method for removing particulate debris from a pipeline comprising, inserting a debris entraining gel plug into the pipeline with at least one pseudoplastic plug; moving the gel plug through the pipeline by a circulating motion essentially generating a closed toroid, the wall of the toroid adjacent the wall of the pipeline remaining relatively stationary and the center moving in the direction of motion of the gel plug; collecting at least part of the particulate debris with the gel plug; moving the pseudoplastic plug through the pipeline by viscoelastic flow; sealing the gel plug from fluid in the pipeline with the pseudoplastic plug; isolating the gel plug from the pseudoplastic plug with a mechanical separator; and collapsing the separator up to 40% of the diameter of the pipeline while moving the separator over debris in the pipeline and while substantially maintaining the seal between the gel plug and pseudoplastic plug.
Claim 2
Independent Claim
150 words
A method for removing particulate debris from a pipeline comprising, inserting a debris entraining gel plug into the pipeline with at least one pseudoplastic plug; moving the gel plug through the pipeline by a circulating motion essentially generating a closed toroid, the wall of the toroid adjacent the wall of the pipeline remaining relatively stationary and the center moving in the direction of motion of the gel plug; collecting at least part of the particulate debris with the gel plug; moving the pseudoplastic plug through the pipeline by viscoelastic flow; sealing the gel plug from fluid in the pipeline with the pseudoplastic plug; isolating the gel plug from the pseudoplastic plug with a mechanical separator; and collapsing the separator up to 40% of the diameter of the pipeline while moving the separator over debris in the pipeline and while substantially maintaining the seal between the gel plug and pseudoplastic plug.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein the gel plug is between pseudoplastic plugs and a trailing mechanical separator prevents displacement fluid pushing the gel plug and pseudoplastic plug from displacing forward into the gel plug.
Claim 4
Dependent Claim
34 words
The method of claim 1, wherein the viscoelastic flow is characterized by erratic start-stop movement of random portions of the plug as adhesive attraction to the pipe and shear stress alternately exceed each other.
Claim 5
Dependent Claim
18 words
The method of claim 1, wherein the separator is a polyurethane conical disc supported by a steel body.
Claim 6
Dependent Claim
15 words
The method of claim 1, wherein the pseudoplastic plug comprises a high molecular weight polyacrylamide.
Claim 7
Dependent Claim
13 words
The method of claim 5, wherein the polyacrylamide is complexed with aluminum nitrate.
Claim 8
Dependent Claim
16 words
The method of claim 1, wherein the pseudoplastic plug comprises crude oil and a gelling agent.
Claim 9
Dependent Claim
21 words
The method of claim 4 wherein the separator includes at least four conical discs and has dewatering discs at each end.
Claim 10
Dependent Claim
40 words
The method of claim 1, wherein the gel plug is between pseudoplastic plugs and the separators each comprise at least four polyurethane conical discs supported by a steel body and having dewatering discs at either end of the steel body.
References Cited (Backward Citations)
US2402796A
Cited
US3108012A
Cited
US3209771A
Cited
US3523826A
Cited
US3879790A
Cited
US4003393A
Cited
US4216026A
Cited
US4254559A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-21 | 1987-05-23 | 1987-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-21 | 1991-05-23 | 1991-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-21 | 1995-05-23 | 1995-11-22 | $7700.00 | Window Closed / Lapsed |