Ecolab USA Inc.

Champion Technologies Limited

Nalco Company

Curtis Sitz

Julie Hardy

Harry Montgomerie

Scot Bodnar

Michael Gregory Rudel

Andrew Frederick Miles

Rex M S Wat

Henry C Fisher

James M Reizer

A method of inhibiting scale in a subterranean formation comprises pretreating the subterranean formation with a polyquaternary amine that serves as a squeeze life extension (SLE) agent, and then introducing a scale inhibitor pill into the subterranean formation, wherein the scale inhibitor pill includes one or more scale inhibitor compositions. For example, the polyquaternary amine may be a polymer having up to 5 quaternary amine centers, but is preferably a nonpolymeric diquaternary amine having a molecular weight of from 250 to 500. One such example is 1,3-propandiaminium, 2-hydroxy-N,N,N,N',N&#x2032;,N&#x2032;-hexamethyl-, dichloride. The SLE agent is preferably introduced into the formation in a brine solution having a concentration from 0.1 to 20 weight percent. The SLE agents may be used with a variety of known scale inhibitors and scale inhibitor chemistries.

Use of oligo-quaternary compositions to increase scale inhibitor lifetime in a subterranean formation

Alkyl phosphonates prepared from amino acids suitable for use in inhibiting scale. The phosphonates are obtained as reaction mixtures where the level of alkyl phosphonation is deliberately controlled to provide only partial alkyl phosphonation of the amino acid. The resulting alkyl phosphonates exhibit improved environmental properties compared to the fully substituted species, while still exhibiting acceptable efficacy in the control of scale. The compositions possess advantages over existing phosphonates in that they exhibit higher biodegradation by method OECD 306. They also offer lower toxicity to marine life compared to the fully substituted species and are not expected to bioaccumulate.

Preparation of environmentally acceptable scale inhibitors

The present invention provides compositions of oil-soluble inhibitors suitable for use in inhibiting oil field scale formation. The compositions comprise an acid form of a known scale inhibitor and a tertiary alkyl primary amine. These compositions possess advantages over conventional compositions used for inhibiting oil field scale.

Scale inhibitors

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Katy, TX, United States of America

Curtis Sitz