Method for forming a cement annulus for a well
A method for forming an annulus around the outer wall of a well casing to provide a good impervious seal around such casing. A wiper of a flexible soft material which mates with the inner bore of the casing is first placed in the casing at the top thereof. Cement is pumped into the casing on top of the wiper, forcing it down to the bottom of the casing, the wiper carrying mud and other foreign material with it and out of the casing. Sonic energy at a relatively low frequency (typically 15-200 Hz) is appliced to the casing. A second wiper which mates with the inner walls of the casing is installed therein, this second wiper being of a rigid, relatively inflexible material. While the sonic energy is being applied, mud or water is fed into the casing on top of the second wiper to force this wiper against the column of cement such that the first wiper is forced out the bottom of the casing and the column of cement forced into the spacing between the casing and the well bore, thereby forming an annulus therearound which rises from the bottom to the top of the casing.
- Assignee:
- EDB-85-153348
- Patent Number(s):
- US 4512401
- OSTI ID:
- 5358200
- Resource Relation:
- Patent File Date: Filed date 27 May 1982; Other Information: PAT-APPL-382700
- Country of Publication:
- United States
- Language:
- English
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