US5076364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas hydrate inhibition
Assignee: Shell USA Inc
•
Filing: 1991-03-19
•
Granted: 1991-12-31
•
Expires: 2011-03-19
Abstract
Abstract Gas hydrate formation in a gas well is prevented by injecting a carrier and an alcohol (e.g., glycerol or a glycerol derivative) into the well and connected facilities/pipelines.
Inventors
- 👤 Arthur H. Hale
- 👤 Ashok K. R. Dewan
- 👤 George C. Blytas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:47
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/52; E; E21; E21B; E21B37/00; E21B37/06; E21B43/00; C09K2208/00; C09K2208/22; Y; Y10; Y10S; Y10S507/00; Y10S507/925
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
33 words
A process for inhibiting gas hydrate formation in the production fluid of a well, connected facilities and pipelines of the well comprising injecting into the well inhibitor comprising a carrier and a polycyclicpolyetherpolyol.
Claim 2
Dependent Claim
33 words
A process for inhibiting gas hydrate formation in the production fluid of a well, connected facilities and pipelines of the well comprising injecting into the well inhibitor comprising a carrier and a polycyclicpolyetherpolyol.
Claim 3
Dependent Claim
41 words
The method of claim 1 wherein the polycyclicpolyetherpolyol which is characterized by binodal molecular weight distribution, M w in excess of 50,000, said M w being determined in a three-column gel permeation chromatography, and being 0.5 to 10% w epoxy structures.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein the polycyclicpolyetherpolyol is further characterized by molecular structures which are no more than 20% free of associated cyclic formations.
Claim 5
Dependent Claim
90 words
A process for shutting-in a well having a fluid therein which is susceptible to the formation of gas hydrates, comprising: preparing a gas hydrate inhibitor by admixing an alcohol with a carrier, said carrier and said alcohol and the quantities thereof being selected to be compatible with the well and effective to prevent the formation of gas hydrates in said well fluid; selecting an appropriate location, depending upon the type of well being shut-in, and injecting the gas hydrate inhibitor into said well at said location; and shutting-in the well.
Claim 6
Dependent Claim
90 words
A process for shutting-in a well having a fluid therein which is susceptible to the formation of gas hydrates, comprising: preparing a gas hydrate inhibitor by admixing an alcohol with a carrier, said carrier and said alcohol and the quantities thereof being selected to be compatible with the well and effective to prevent the formation of gas hydrates in said well fluid; selecting an appropriate location, depending upon the type of well being shut-in, and injecting the gas hydrate inhibitor into said well at said location; and shutting-in the well.
Claim 7
Dependent Claim
13 words
The process of claim 4 wherein the hydrate inhibitor includes an inorganic salt.
Claim 8
Dependent Claim
33 words
The process of claim 4 wherein the hydrate inhibitor includes from 5% by weight to 25% by weight salt and wherein the alcohol is from 10% by weight to 40% by weight glycerol.
Claim 9
Dependent Claim
34 words
The process of claim 4 wherein the well is an offshore tension leg platform and the hydrate inhibitor injection location is selected from a connected facilities/pipeline or tubing above or below the mud line.
Claim 10
Dependent Claim
53 words
The process of claim 4 wherein the shut-in is for emergency purposes, the well is to be temporarily abandoned by a drill-ship, and the hydrate inhibitor is in the form of a pill comprising drilling fluid carrier admixed with said alcohol, said pill being injected into a blowout preventor associated with the well.
Claim 11
Dependent Claim
32 words
The process of claim 4 wherein the well is a producing well which is to be temporarily shut-in, the hydrate inhibitor being injected into the well tubing and mixing with produced water.
Claim 12
Dependent Claim
22 words
The process of claim 4 wherein the carrier is selected from the group consisting of polymer-based drilling fluids and bentonite-based drilling fluids.
Claim 13
Dependent Claim
67 words
The process of claim 4 wherein the alcohol is selected from the group consisting of (1) an acyclic polyol having 3 to 80 carbon atoms and 2 to 60 hydroxyl groups, (2) a monocyclicpolyol having 5 to 30 carbon atoms and 2 to 10 hydroxyl groups, and (3) a cyclicetherpolyol having 6 to 1800 carbon atoms, 2 to 450 hydroxyl groups, and 2 to 600 ether linkages.
References Cited (Backward Citations)
US2191312A
Cited
US3223622A
Cited
US3301323A
Cited
US3348614A
Cited
US3728259A
Cited
US3738437A
Cited
US4053422A
Cited
US4456067A
Cited
US4508628A
Cited
US4478612A
Cited
US4597779A
Cited
US4802998A
Cited
US4856593A
Cited
EP0324887A2
Cited
GB2216574A
Cited
GB2216573A
Cited
EP0339270A2
Cited
GB2223255A
Cited
EP0374671A1
Cited
EP0374672A1
Cited
EP0382070A1
Cited
EP0382071A1
Cited
EP0386638A1
Cited
EP0386636A1
Cited
EP0391251A1
Cited
EP0391252A1
Cited
EP0398113A1
Cited
EP0398112A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |