Random acrylic terpolymers of controlled molecular mass employed in the destabilization of W/O simple and/or O/W/O complex emulsions in crude oils

A random terpolymer based on alkyl acrylate-ethylene alkanoate-alkoxyalkyl acrylate as a dehydrating agent of crude oil, comprising a structural formula of molecular masses between 1,150 and 994,000 g·mol−1 as follows:

• where:
• R1, R2, R3, R4, R5 and R6 are independent radicals represented by the following groups:
• R1=CH3 (methyl), C2H5 (ethyl), C4H9 (n-butyl), C4H9 (iso-butyl), C4H9 (tert-butyl), C5H11 (pentyl), C6H13 (n-hexyl), C6H11 (di(ethylene glycol)ethylether), C8H17 (2-ethylhexyl), C9H19 (3,5,5-trimethylhexyl), C8H17 (n-octyl), C8H17 (iso-octyl), C8H9 (ethylene glycol phenyl ether), C10H21 (n-decyl), C10H21 (iso-decyl), C10H19 (10-undecenyl), C10H19 (tert-butylcyclohexyl), C12H25 (n-dodecyl), C18H37 (n-octadecyl), C5H9O (tetrahydrofurfuryl), C5H9O (2-tetrahydropyranyl), C13H27 (tridecyl), or C22H45 (behenyl), and can include, in an aliphatic chain, at least one of heteroatoms of ether groups and benzene type aromatic rings or heteroatoms rings of ether groups;
• R2=CH3 (methyl), C2H5 (ethyl), C3H7 (propyl), C4H9 (n-butyl), (CH3)3C (t-butyl), C6H5 (phenyl), C8H17 (n-octyl), C9H19 (n-nonyl), C11H23 (undecyl), or C17H35 (octadecanyl);
• R3=C2H5O (methoxymethyl), C3H7O (2-methoxyethyl), C4H9O (2-ethoxyethyl), C4H9O (3-methoxipropyl), C5H11O (3-ethoxypropyl), C5H11O2 (2-(2-methoxyethoxi)ethyl), or C8H9O (2-phenoxyethyl), wherein an alkylalkoxy fragment could include phenyls, alkyls of cyclic or branched chain from C1 to C20;
• R4 and R6=H (hydrogen) and/or CH3 (methyl);
• and
• R5=H, CH3 and/or CN;
• wherein:
• x=is a number set up from 4 to 1075;
• y=is a number set up from 4 to 1075;
• z=is a number set up from 4 to 1075;
• and
• x, y and z may optionally occur as random sequences.