US 12,448,557 B2
Emulsion stabilizing agents
Laura Viganò, Parabiago (IT)
Assigned to Lamberti SPA, Albizzate (IT)
Appl. No. 18/564,984
Filed by Lamberti SPA, Albizzate (IT)
PCT Filed Jun. 27, 2022, PCT No. PCT/EP2022/067605
§ 371(c)(1), (2) Date Nov. 28, 2023,
PCT Pub. No. WO2023/274976, PCT Pub. Date Jan. 5, 2023.
Claims priority of application No. 102021000016916 (IT), filed on Jun. 28, 2021.
Prior Publication US 2024/0287374 A1, Aug. 29, 2024
Int. Cl. C09K 8/36 (2006.01); C08G 69/28 (2006.01)
CPC C09K 8/36 (2013.01) [C08G 69/28 (2013.01); C09K 2208/12 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A water-in-oil subterranean treatment fluid, comprising an aqueous phase, an oil phase and from 0.3 to 5.0 g/100 ml of an emulsion stabilizing agent, which is a polyamide obtained by reacting in a first step:
a) one mole of a polyamine having n amino groups with exchangeable hydrogens, wherein n is an integer ranging from 3 to 5; and
b) from n/2 to n-0.8 moles of a C6-C30 saturated or unsaturated aliphatic monocarboxylic acid or an ester thereof or mixtures thereof;
to obtain an aminoamide characterized by a saponification number below 30 mgKOH/g; and, subsequently, in a second step, reacting the aminoamide with:
c) from 0.4 to 1.1 moles of a C4-C6 unsaturated dicarboxylic acid or with the corresponding anhydride for each mole of remaining amino groups bearing exchangeable hydrogens;
to obtain the polyamide; with the proviso that during or after the second step the reaction mass is heated at temperature ranging from 130 to 200° C. until at least 30 by weight (wt %) of the emulsion stabilizing agent has a molecular weight higher than 1700 Da, as determined by organic gel permeation chromatography calibrated with polyethylene glycol standards;
wherein said emulsion stabilizing agent of which at least 30 wt % has a molecular weight higher than 1700 Da has a total recovery in a shale recovery test higher than a polyamide prepared identically except for not being heated to the temperature ranging from 130 to 200° C.