METHOD OF USING A SPACER FLUID FOR SPACING DRILLING MUDS AND CEMENT

• US 3,850,248 A
• Filed: 11/19/1973
• Issued: 11/26/1974
• Est. Priority Date: 11/19/1973
• Status: Expired due to Term

• Current Assignee: M-I Drilling Fluids Company
• Original Assignee: Leroy I. Carney
• Inventors: Carney, Leroy I.
• Primary Examiner(s): Novosad, Stephen J.
• Application Number:
  US05/417,431
• Time in Patent Office: 372 Days
• Field of Search: 166/291,285 252/8.5P,8.55A
• US Class Current: 166/291
• CPC Class Codes: C09K 8/40 Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses
• CPC Class Codes: C09K 8/424 using "spacer" compositions
• CPC Class Codes: Y10S 507/928 Spacing slug or preflush fluid

Abstract

A spacer fluid emulsion comprising approximately equal volume parts of a hydrocarbon oil and fresh water, and containing from about 15 pounds per barrel to about 40 pounds per barrel of an emulsifier, about 0.5 pounds per barrel to about 10 pounds per barrel of a strong surfactant-dispersant, and a weighting material in an amount effective to impart a density to the spacer fluid of from about 8 pounds per gallon to about 20 pounds per gallon. The emulsifier used comprises an oleyl amide, preferably in admixture with oleic acid and dimerized oleic acid, adsorbed on a solid carrier selected from the group consisting of lime, as herein defined, and diatomaceous earth. The surfactant-dispersant preferably comprises a mixture of about equal weight parts of waste sulfite liquor, and the reaction product derived from the reaction of oleyl chloride and n-methyltaurine. The invention is further directed to methods of using such spacer fluids between cement and drilling fluids during well completions.

Claims

1. A METHOD FOR ENHANCING THE COMPLETION OF CASED BORE HOLES DRILLED INTO THE EARTH USING DRILLING MUD COMPRISING:

PREPARING A WATER-IN-OIL EMULSION SPACER FLUID CONTAINING APPROXIMATELY EQUAL AMOUNTS OF HYDROCARBON OIL AND FRESH WATER, AND FURTHER CONTAINING AN EFFECTIVE AMOUNT OF AN EMULSIFIER COMPRISING A FATTY ACID AMIDE OF FROM 15 TO 22 CARBON ATOMS ADSORBED ON A SOLID FLUID, AN EFFECTIVE AMOUNT INCORPORATING IN THE SPACER FLUID, AN EFFECTIVE AMOUNT OF A VISCOSITY INCREASING AGENT AND A SULFACANT-DISPERSANT TO FACILITATE ADDITION TO THE SPACER FLUID OF THE HEREINAFTER DESCRIBED QUANTITY OF WEIGHTING MATERIAL, SAID SURFACTANTDISPERSANT COMPRISING A MIXTURE OF WASTE SULFITE LIQUOF AND AN OLEYL AMIDE;

SELECTING A CEMENTING COMPOSITION FOR CEMENTING THE CAUSING IN THE BORE HOLE BY PLACEMENT OF THE CEMENT IN THE ANNULUS AROUND THE CASING;

ADDING WEIGHTING MATERIAL TO SAID SPACER FLUID IN A QUANTITY SUFFICIENT TO IMPART A WEIGHT TO THE SPACER FLUID WHICH DOES NOT EXCEED THE WEIGHT OF SAID CEMENTING COMPOSITION, AND IS NOT LESS THAN THE WEIGHT OF THE DRILLING MUD USED IN DRILLING THE BORE HOLE;

CIRCULATING INTO SAID ANNULUS IN AN UPWARD DIRECTION IN THE BORE HOLE AND BEHIND DRILLING MUD IN THE ANNULUS TO DISPLACE THE DRILLING MUD, A QUANTITY OF SAID SPACER FLUID, FOLLOWED BY A QUANTITY OF SAID CEMENTING COMPOSITION, SO THAT SAID SPACER FLUID IS INTERPOSED BETWEEN THE CEMENTING COMPOSITION AND DRILLING MUD OVER A SUFFICIENT INTERVAL TO PREVENT ANY INTERMIXING OF THE CEMENTING COMPOSITION AND DRILLING MUD.

2. The method defined in claim 1 wherein from about 30 to about 50 barrels of said spacer fluid are interposed between the drilling mud and cementing composition.

3. The method defined in claim 1 wherein the emulsifier utilized in the cement comprises an oleyl amide derived from the condensation of oleic acid with diethanolamine, and wherein said solid particulate carrier is calcium hydroxide.

4. The method defined in claim 3 wherein said viscosity increasing agent is dimerized oleic acid, and said surfact-dispersant is a mixture of substantially equal weight parts of waste sulfite liquor and a reaction product of oleyl chloride with n-methyltaurine.