Nova Patents
EP0840769B2

Non-toxic, inexpensive synthetic drilling fluid

Abstract

This record has no abstract on file.

Term

Term ended

Expired 10 July 2016, 10.2 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

21 claims: 9 independent, 12 dependent

  1. 1
    A wellbore fluid comprising:(I) a non-toxic base fluid;and (II) at least, one additive selected from the group consisting of emulsifiers, wetting agents, viscosifiers, weighting agents, fluid loss control agents, proppants for use in hydraulically fracturing subterranean formations, and particulate agents for use in forming a gravel pack;wherein the base fluid is a synthetic hydrocarbon mixture, which hydrocarbon mixture comprises at least 2 hydrocarbons containing a consecutive number of carbon atoms and is selected from the group consisting of: (A) a hydrocarbon mixture having a pour point greater than -30°C and a cetane index greater than 50, comprising (i) at least 90 weight percent total paraffins selected from n-paraffins and iso-paraffins, wherein n-paraffins constitute at least 10, weight percent and iso-parrafins constitute at least 50 weight percent;(ii) at least 95 weight percent hydrocarbons containing 11 or more carbon atoms;(iii) greater than 5 weight percent hydrocarbons containing 18 or more carbon atoms;(iv) 1 or less weight percent naphthenics;and (v) 0.1 or less volume percent aromatics;and (B) a hydrocarbon mixture comprising (i) at least 90 weight percent n-paraffins;and (ii) at least 95 weight percent hydrocarbons containing 10 or more carbon atoms.
  2. 4
    A wellbore fluid according to any one of claims 2-3, wherein the base fluid has an API gravity at 15°C (59°F) greater than 40°.
  3. 5
    A wellbore fluid according to any one of claims 2-4, wherein the base fluid comprises less than 1 weight percent polar activator.
  4. 6
    A wellbore fluid according to any one of claims 2-5, wherein the base fluid has an initial boling point of at least 160°C (320°F).
  5. 7
    A wellbore fluid according to any one of claims 2-6, wherein the base fluid has a final bolling point of from 350°C (662°F) to 375°C (707°F).
  6. 8
    A wellbore fluid according to any one of claims 2-7, wherein the base fluid comprises at least 95 weight percent hydrocarbons containing 12 or more carbon atoms.
  7. 9
    A wellbore fluid according to any one of claims 2-8, wherein the base fluid comprises greater than 10 or greater than 15 weight percent hydrocarbons containing 18 or more carbon atoms.
  8. 10
    A wellbore fluid according to any one of claims 2-9, wherein the base fluid comprises less than 95 or less than 90 weight percent isoparaffin.
  9. 20
    Use of a wellbore fluid as defined in any one of claims 1-19 as a drilling fluid in a method for drilling a borehole in a subterranean formation, wherein the method comprises the steps of:(A) rotating a drill at the bottom of the borehole;and (B) introducing said drilling fluid into the borehole to pick up drill cuttings and to carry at least a portion of the drill cuttings out of the borehole.
Independent claims9