Wells – Processes – Heating – cooling or insulating
Patent
1986-06-26
1987-09-15
Novosad, Stephen J.
Wells
Processes
Heating, cooling or insulating
166 57, 166242, 166380, E21B 3600, E21B 4324
Patent
active
046933131
ABSTRACT:
An insulated well casing is described that includes an inner tubular member and an outer tubular casing member joined together at their ends by a weldment, typically formed into a thrust cone suitable for joining strings of insulated casings to insulate and encase the entire depth of a well for delivery of steam, for example, into a producing formation. A key element of the invention is pre-stressing the integrated casing by tensioning the inner tubular member at a level less than the yield strength of the tubular material prior to joining the weldments of the unit together. The resulting integrated casing includes a tensioned inner tubular member and an outer member that is in compression. The tensioning load is selected such that at well operating temperatures and pressures, the compressive stresses exerted upon the casing at the bottom of the hole approach the compressive yield strengt of the inner tubular member, but leave a desired margin of safety. The casing of the invention permits injecting high-temperature steam at 450.degree.-700.degree. F. adjacent the insulated casing and recovering product from the formation through a central annular uninsulated tubing. The temperature and stress experienced by the outer tubular casing member, grouted to the wellbore are such that the adhesive bonds between the casing and the formation remain intact and the casing is not significantly deformed. The insulated casing of the invention reduces heat loss from the injected steam to the surrounding formations to less than 1%.
REFERENCES:
patent: Re28152 (1974-09-01), Waters
patent: 3397745 (1968-08-01), Owens et al.
patent: 3456735 (1969-07-01), McDougall et al.
patent: 3511282 (1970-05-01), Willwhite et al.
patent: 3608640 (1971-09-01), Willhite et al.
patent: 3650327 (1972-03-01), Burnside
patent: 3680631 (1972-08-01), Allen et al.
patent: 3722591 (1973-03-01), Maxson
patent: 3749163 (1973-07-01), Waters
patent: 3762469 (1973-10-01), Babb
patent: 3763931 (1973-10-01), Waters
patent: 3763935 (1973-10-01), Perkins
patent: 3820605 (1974-06-01), Barber et al.
patent: 4024919 (1977-05-01), Pujol
patent: 4139024 (1979-02-01), Adorjan
patent: 4296814 (1981-10-01), Stalder et al.
patent: 4332401 (1982-06-01), Stephenson et al.
patent: 4403656 (1983-09-01), Ploeg et al.
patent: 4415184 (1983-11-01), Stephenson et al.
patent: 4480371 (1984-11-01), McStravick et al.
patent: 4496001 (1985-01-01), Sigworth, Jr.
patent: 4512721 (1985-04-01), Ayres et al.
Howe Raymond C.
Stephenson Edgar O.
Kawasaki Thermal Systems, Inc.
Novosad Stephen J.
LandOfFree
Insulated wellbore casing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Insulated wellbore casing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Insulated wellbore casing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1379021