US 12,247,155 B2
Additives to temporarily reduce viscosities in oil-based fluids
Dimitri Khramov, Katy, TX (US)
Assigned to SCHLUMBERGER TECHNOLOGY CORPORATION, Sugar Land, TX (US)
Filed by Schlumberger Technology Corporation, Sugar Land, TX (US)
Filed on Dec. 14, 2023, as Appl. No. 18/539,837.
Application 18/539,837 is a division of application No. 17/616,215, granted, now 11,879,088, previously published as PCT/US2020/039374, filed on Jun. 24, 2020.
Claims priority of provisional application 62/867,231, filed on Jun. 27, 2019.
Prior Publication US 2024/0132768 A1, Apr. 25, 2024
Int. Cl. C09K 8/035 (2006.01); E21B 21/06 (2006.01)
CPC C09K 8/035 (2013.01) [E21B 21/068 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A wellbore fluid comprising:
a base fluid comprising an oil-based fluid wherein the oil-based fluid is an invert emulsion containing an aqueous discontinuous phase and an oil-based continuous phase; and
an additive comprising:
a reaction product of a first reactant and a second reactant;
the reaction product comprising at least one cleavable ester;
the first reactant is at least one alcohol, at least one alcohol ethoxylate, or at least one combination thereof, wherein the at least one alcohol is at least one of oleyl alcohol, 2-ethylhexyl alcohol, 2-ethylhexyl cellosolve, 2-ethylhexyl carbitol, hexyl cellosolve, at least one linear alcohol, at least one branched alcohol, at least one Fisher-Tropsch alcohol, or at least one Guerbet alcohol, and wherein the at least one alcohol ethoxylate is at least one of oleyl alcohol having 2 ethoxy units, oleyl alcohol having 3 ethoxy units, benzyl alcohol having 2 ethoxy units, or benzyl alcohol having 4 ethoxy units;
the second reactant comprising at least one anhydride; and
a temporary thinning effect of the additive in the oil-based fluid being deactivatable by hydrolysis of at least one ester bond of the reaction product.