| 摘要 |
A storable, hydraulically-active, cementitious slurry is made and used to cement within subterranean foundations for oil and gas wells. The slurry is made from a hydraulically-active cementitious material, a suspending agent, and, as a retarder, boric acid. The boric acid is present in the cementitious slurry in an amount sufficient to lower the pH of the storable cementitious slurry to at least 12.0, preferably to at least 11.0 or preferably, for reasons of longevity, to a pH of at least 9.0. Generally the amount of boric acid in the cementitious slurry is between from about 1 to about 6 percent by weight. Preferred as suspending agent are iota carrageenan as well as poly (methyl vinyl ether/maleic anhydride) decadiene copolymer. The slurry remains liquid during storage. The slurry is activated when needed for cementing and is pumped into the subterranean formation where it is allowed to set.
|
