US 12,168,913 B2
Methods for transporting scale removal agents into a well
John Mayor, Cypress, TX (US); Kelly Guilbeau Berard, Breaux Bridge, LA (US); and Marty J. Usie, Youngsville, LA (US)
Filed by Baker Hughes Oilfield Operations LLC
Filed on May 12, 2022, as Appl. No. 17/742,971.
Prior Publication US 2023/0366296 A1, Nov. 16, 2023
Int. Cl. E21B 37/06 (2006.01); C09K 8/74 (2006.01); C09K 23/18 (2022.01)
CPC E21B 37/06 (2013.01) [C09K 8/74 (2013.01); C09K 23/18 (2022.01); C09K 2208/30 (2013.01)] 20 Claims
OG exemplary drawing
 
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):

OG Complex Work Unit Chemistry
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.
 
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.