Well completion spacer fluids and methods
AssigneesHalliburton Company, Atlantic Richfield Company
InventorsRobert B. Carpenter, J. Michael Wilson, Bill W. Loughridge, David L. Johnson, Krishna M. Ravi, Richard R. Jones
Life of this patent
Estimating the term…
Abstract
A well completion spacer fluid is provided which is particularly suitable for separating a cement slurry from drilling fluid in primary cementing operations. The well completion spacer fluid is also useful for separating other potentially incompatible fluids in the wellbore, such as, separating drilling fluid from a completion brine. The spacer fluid basically comprises water, a hydrous magnesium silicate clay, silica and organic polymer(s).
Claims22
A composition for forming an aqueous well completion spacer fluid comprising:
- a hydrous magnesium silicate clay selected from the group consisting of sepiolite and attapulgite present in an amount in the range of from about 15% to about 85% by weight of said composition;
- silica present in an amount in the range of from about 15% to about 85% by weight of said composition;
- and
- an organic polymer selected from the group consisting of whelan gum, xanthan gum, galactomannan gums, succinoglycan gums, scleroglucan gums and cellulose and its derivatives present in an amount in the range of from about 0.5% to about 10% by weight of said composition.
A well completion spacer fluid comprising:
- water;
- a hydrous magnesium silicate clay selected from the group consisting of sepiolite and attapulgite present in said spacer fluid in an amount in the range of from about 0.1% to about 17% by weight of water therein;
- fumed silica present in said spacer fluid in an amount in the range of from about 0.1% to about 17% by weight of water therein;
- and
- an organic polymer selected from the group consisting of whelan gum, xanthan gum, galactomannan gums, succinoglycan gums, scleroglucan gums and cellulose and its derivatives present in said spacer fluid in an amount in the range of from about 0.05% to about 2.5% by weight of water therein.
A well cement/drilling fluid spacer fluid comprising:
- water;
- sepiolite clay present in an amount in the range of from about 0.5% to about 10% by weight of water;
- fumed silica present in an amount in the range of from about 0.5% to about 10% by weight of water;
- about a 3:1 by weight mixture of welan gum and hydroxyethylcellulose present in an amount in the range of from about 0.05% to about 1.2% by weight of water;
- and
- barite present in an amount sufficient to increase the density of said spacer fluid to a level in the range of from about 9 pounds to about 24 pounds per gallon of spacer fluid.
In a method of displacing a first fluid with an incompatible second fluid in a well utilizing a spacer fluid to separate the first fluid from the second fluid and to remove the first fluid from the walls of the well, the improvement comprising using a spacer fluid comprised of water, a hydrous magnesium silicate clay selected from the group consisting of sepiolite and attapulgite, silica, and an organic polymer selected from the group consisting of welan gum, xanthan gum, galactomannan gums, succinoglycan gums, scleroglucan gums and cellulose and its derivatives.
Dependencies are inferred from the claim text.