CPC E21B 37/06 (2013.01) [C09K 8/74 (2013.01); C09K 23/18 (2022.01); C09K 2208/30 (2013.01)] | 20 Claims |
1. A method of transporting a scale removal agent into a well having deposits of scale, the method comprising:
(a) pumping a gelled fluid comprising a viscoelastic surfactant and the scale removal agent into the well wherein the viscoelastic surfactant is stable up to a temperature of at least 300° F. and further wherein the viscoelastic surfactant is an alkylamidoquaternary amine of the structural formula (I):
![]() wherein:
R1 is a saturated or unsaturated, hydrocarbon group of from about 17 to about 29 carbon atoms;
R2 and R3 are independently selected from a straight chain or branched, alkyl or hydroxyalkyl group of from 1 to about 6 carbon atoms;
R4 is selected from —H, —OH, alkyl and hydroxyalkyl groups of from 1 to about 4 carbon atoms;
k is an integer of from about 2 to about 20;
m is an integer from about 1 to about 20; and
n is an integer of from 0 to about 20;
(b) releasing the gelled fluid into the well at a bottomhole temperature in excess of 300° F.
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19. A method of transporting a scale removal agent into a well having deposits of scale, the method comprising:
(a) pumping a gelled fluid comprising a viscoelastic surfactant and the scale removal agent into the well wherein the viscoelastic surfactant is stable up to a temperature of at least 300° F. and selected from the group consisting of erucamidopropyl hydroxypropyl sulfobetaine, erucamido hydroxysultaine, erucamidopropyl hydroxyethyl sulfobetaine, erucamidopropyl hydroxymethyl sulfobetaine and mixtures thereof;
(b) releasing the scale removal agent from the gelled fluid at a controlled rated into the well at a bottomhole temperature in excess of 300° F.
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