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Oil well fluids and dispersants

  • US 4,108,779 A
  • Filed: 04/15/1976
  • Issued: 08/22/1978
  • Est. Priority Date: 05/01/1973
  • Status: Expired due to Term
First Claim
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1. A water-in-oil emulsion spacer fluid which is compatible with drilling fluids and cement compositions and which can be used effectively in a well to separate various types of fluids, cement compositions and combinations thereof without significant alteration in the rheological properties, said spacer fluid comprising about 40-60 parts by volume of a hydrocarbon oil;

  • about 40-60 parts by volume fresh water having, before inclusion of the spacer fluid, a dissolved chloride salt content of less than 1,000 parts per million and a total hardness of less than 500 parts per million; and

    about 15-40 pounds of an emulsifier composition per barrel of said spacer fluid;

    said emulsifier composition consisting essentially of about 1-20 weight percent of a first fatty acid amide, wherein the fatty acid precursor contains about 12-18 carbon atoms and the amide contains about 16-22 carbon atoms and about 0.5-10 pounds per barrel of spacer fluid of a surfactant-dispersant comprising a mixture of sulfonated lignin and a second fatty acid amide;

    wherein for said surfactant-dispersant, said sulfonated lignin is mixed with said second fatty acid amide in an amount equal to about 25-75% of said mixture;

    wherein said first fatty acid amide is the reaction product of a di-lower alkanol amine and said fatty acid; and

    wherein the amine precursor of the second fatty acid amide is an alkyl or aryl amino sulfonic acid, wherein the alkyl or aryl radicals contain 1-6 carbon atoms.

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