Compositions for controlled release

• US 6,723,683 B2
• Filed: 08/07/2001
• Issued: 04/20/2004
• Est. Priority Date: 08/07/2001
• Status: Expired due to Term

• Current Assignee: Nouryon Chemicals International B.V. (Nouryon BV)
• Original Assignee: National Starch and Chemical Investment Holding Corporation
• Inventors: Rosie, James A., Crossman, Martin C., Solarek, Daniel B
• Primary Examiner(s): Tucker, Philip C.
• Application Number:
  US09/924,179
• Publication Number:
  US 20030032562A1
• Time in Patent Office: 987 Days
• Field of Search: 507/111, 507/212, 507/90, 507/939, 507/927, 507/920, 507/921, 507/930, 507/931, 507/118, 507/110, 507/211, 507/221, 507/902
• US Class Current: 507/111
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 3/00 Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
• CPC Class Codes: C08L 3/02 Starch; Degradation products thereof, e.g. dextrin
• CPC Class Codes: C08L 3/06 Esters
• CPC Class Codes: C09K 8/536 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: C09K 8/706 Encapsulated breakers
• CPC Class Codes: C09K 8/92 characterised by their form or by the form of their components, e.g. encapsulated material C09K8/70 takes precedence
• CPC Class Codes: Y10S 507/902 Controlled release agent
• CPC Class Codes: Y10S 507/92 Biocidal
• CPC Class Codes: Y10S 507/921 Specified breaker component for emulsion or gel
• CPC Class Codes: Y10S 507/927 Well cleaning fluid
• CPC Class Codes: Y10S 507/93 Organic contaminant is asphaltic
• CPC Class Codes: Y10S 507/931 Organic contaminant is paraffinic
• CPC Class Codes: Y10S 507/939 Corrosion inhibitor

Abstract

The present invention relates to biodegradable chemical compositions wherein core substrates, particularly oil well chemicals, are adsorbed onto particulate starch, particularly granular starch, providing a stable, controlled release formulation suitable for use in oil field applications. The invention further relates to the process of preparing obtaining these compositions.

Claims

1. A biodegradable controlled release chemical composition composing

(a) a granular, pitted, particulate octenylsuccinate starch,

(b) at least one oil well chemical selected from the group consisting of friction reducers, corrosion inhibitors, wax inhibtors, hydrate inhibitors, gel breakers, tracers, surfactants, scale inhibitors, antifoaming agents, demulsifiers, pour point depressants, biocids, drag reducers, antioxidants, hydrogen sulfide sulfied scavengers, oxygen scavengers, deoilers, and asphaltene inhibitors, and

(c) an adjunct selected from the group consisting of a plasticizer, surfactant, filler, chelating agent, thickening agent, particulate, gelatin, gum arabic, zein, soy protein, and polymers/coplomers of polyethylene and polyvinyl chloride.

wherein the starch is chosen to release the chemical at 60°

C.

2. A composition comprising a mixture of at least two compositions according to claim 1, wherein the chemicals are incompatible with one another.