Spacer fluid compositions, methods, and systems for aqueous based drilling mud removal
AssigneeSaudi Arabian Oil Company
InventorsHussain AlBahrani, Abdullah Al-Yami, Vikrant Wagle
Life of this patent
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Abstract
Spacer fluids include an emulsion, a surfactant package, and at least one additive that modifies the rheology of the spacer fluid, the density of the spacer fluid, or both. The emulsion may include an aqueous external phase and a hydrocarbon-based internal phase. The surfactant package may include one or more surfactants. The surfactant package may also include a surfactant having the general structure R—(OCH2CH2)9—OH, where R is a hydrocarbyl having 12 carbon atoms, 13 carbon atoms, or 14 carbon atoms. The spacer fluid may contain at least 4.25 pounds of R—(OCH2CH2)9—OH per barrel of the spacer fluid.
Claims9
A method of removing aqueous muds from a wellbore, the method comprising:
- adding a spacer fluid according to any of the preceding claims to a wellbore comprising an aqueous mud, the spacer fluid comprising:
- an emulsion comprising an aqueous external phase and a hydrocarbon-based internal phase;
- a surfactant package comprising one or more surfactants, where the surfactant package comprises a surfactant having the chemical structure R—(OC2H4)9—OH, where:
- R is a hydrocarbyl having from 12 to 14 carbon atoms and the surfactant has a hydrophilic-lipophilic balance from 11 to 15;
- and
- at least one additive that modifies the rheology of the spacer fluid, the density of the spacer fluid, or both;
- passing the spacer fluid through the wellbore, where at least a portion of the aqueous mud exits the wellbore through a conduit defined by an exterior wall of the tubular and a wall of the wellbore.
The method of claim 13, in which the spacer fluid has a yield point from 10 lbf/100 ft2 to 50 lbf/100 ft2 as measured by American Petroleum Institute Recommended Practice 13B-1.
The method of claim 13, in which the spacer fluid has a yield point from 10 lbf/100 ft2 to 25 lbf/100 ft2 as measured by American Petroleum Institute Recommended Practice 13B-1.
The method of claim 13, in which the hydrocarbon-based internal phase comprises one or more of safra oil, diesel, mineral oil, paraffin oil, ben oil, marula oil, castor oil, palm oil, copra oil, jojoba oil, tung oil, or other oils naturally derived from plants or animals.
The method of claim 13, in which the spacer fluid comprises from 140 pounds to 300 pounds of aqueous external phase per barrel of spacer fluid.
The method of claim 13, in which the spacer fluid comprises from 0.40 pounds to 21 pounds of surfactant package per barrel of spacer fluid.
The method of claim 13, in which the at least one additive comprises one or more of polysaccharides, polyacrylamides, minerals, defoaming agents, BaSO4, CaCO3, Fe2O3, FeCO3, FeTiO, bentonite, xanthan gum polymer, polyanionic cellulose.
The method of claim 13, in which the aqueous mud comprises from 30 pounds to 351 pounds of water per barrel of aqueous mud.
The method of claim 13, in which the aqueous mud comprises from 4 pounds to 420 pounds of alkali metal salt or alkali earth metal salt per barrel of aqueous mud.