Well treatment
View Patent ↗A method for delivering a scale treatment agent to a hydrocarbon producing system. The method includes the steps of contacting the system with a foam comprising the scale treatment agent, and shutting the scale treatment agent in the system for at least 0.5 hour.
1. A method for treating a hydrocarbon-producing geological formation, said method comprising:
providing a foam that includes a scale treatment agent and an alkyl polyglycoside foaming agent;
placing the foam into the hydrocarbon-producing geological formation, causing the foam to remain stable within the hydrocarbon-producing geological formation, and then causing the foam to form a liquid within the hydrocarbon-producing geological formation, and wherein the foam has a static half life of at least 3 minutes and forms a liquid within 1-15 minutes of being placed in the hydrocarbon-producing geological formation, and wherein the liquid includes the scale treatment agent;
shutting said scale treatment agent in said hydrocarbon-producing geological formation for at least 0.5 hour; and
subsequently, removing the liquid from the hydrocarbon-producing geological formation.
2. A method as claimed in claim 1 , wherein said scale treatment agent removes and/or prevents scale.
3. A method as claimed in claim 1 , wherein said scale treatment agent is a scale dissolver, a scale inhibitor or a mixture thereof.
4. A method as claimed in claim 1 , wherein said foam comprises a gas.
5. A method as claimed in claim 1 , wherein said alkyl polyglycoside is a compound of formula I: R 1 O(R 2 O) a (X) b (I), wherein R 1 is C 6-30 alkyl group, R 2 is an alkylene group having from 2 to 4 carbon atoms, X is a saccharide residue having 5 or 6 carbon atoms, a is an integer having a value of 0 to 12, and b is an integer having a value of 1 to 6, or mixtures thereof.
6. A method as claimed in claim 1 , wherein said foam comprises water.
7. A method as claimed claim 1 wherein said foam comprises a scale inhibitor.
8. A method as claimed in claim 7 wherein said scale inhibitor is a polymer formed from monomers of formula (II):
wherein R 3 is —CO 2 Z, —SO 3 Z, —PO 3 Z 2 or an alkyl or aryl group substituted with at least one —CO 2 Z, —SO 3 Z or —PO 3 Z 2 group in which Z is a hydrogen atom or a univalent metal atom; R 4 , R 5 and R 6 are each independently hydrogen, an optionally substituted alkyl or aryl group having from 1 to 6 carbon atoms or a group R 3 as hereinbefore defined.
9. A method as claimed in claim 1 , wherein said foam comprises a scale dissolver.
10. A method as claimed in claim 9 , wherein the scale dissolver comprises potassium carbonate and ester of an aliphatic carbonic acid.
11. A method as claimed in claim 1 , wherein said foam has a static half life of 3 to 20 minutes.
12. A method as claimed in claim 1 , further comprising a pre-flush.
13. A method as claimed in claim 1 , further comprising an after-flush.