Invert drilling fluids having enhanced rheology and methods of drilling boreholes
AssigneeHalliburton Energy Services, Inc.
InventorsShadaab Syed Maghrabi, Vikrant Bhavanishankar Wagle, Kushabhau Dagadu Teke, Dhanashree Gajanan Kulkarni, Kunal Sharad Kulkarni
Life of this patent
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Abstract
An invert emulsion drilling fluid, and a method of drilling with such fluid, having improved rheology at low mud weights and high temperatures. The improved rheology is effected with addition of hydrophobic amines, most preferably dimer diamines.
Claims20
A method for drilling in a subterranean formation comprising providing or using in the drilling an invert emulsion drilling fluid having an oleaginous continuous phase, a non-oleaginous discontinuous phase, and a hydrophobic amine additive,
- wherein the drilling fluid with the hydrophobic amine additive, when compared to the drilling fluid without the hydrophobic amine additive, restricts the increase in plastic viscosity to 60% or less and has a characteristic selected from the group consisting of:
- an increased yield point;
- an increased low shear yield point;
- an increased gel strength;
- and any combination thereof.
An invert emulsion drilling fluid having a mud weight in the range of about 9 ppg to about 18 ppg, comprising:
- a natural or synthetic oil base;
- an aqueous solution;
- and
- a rheology modifier comprising a hydrophobic amine having the following general structure:
- where R is a hydrophobic or partially hydrophobic group with carbon atoms ranging in number from about 16 to about 54, straight chained or branched, and aliphatic, cycloaliphatic or aryl aliphatic;
- N is a primary, secondary or tertiary amine wherein the R1 and R2 groups may be the same or different and are selected from the group consisting of hydrogen, alkyl, cyano alkyl, amino alkyl, amino aryl, hydroxyl alkyl, and derivatives thereof;
- and X comprises a hydrophilic group selected from the group consisting of primary, secondary and tertiary amines with substituents selected from the group consisting of hydrogen, alkyl, cyano alkyl, amino alkyl, amino aryl, hydroxyl alkyl, and derivatives thereof, or X comprises a group selected from the group consisting of amides, amine oxides, betaines, esters, carboxylic acids, ethers, hydroxyl groups, phosphates, phosphonates, pyrrolidones, haloformyl groups, nitrates, nitrites, sulfates, sulfonates, imidazolines, pyridines, sugars, combinations thereof, and derivatives thereof,
- wherein the invert emulsion has an oil:water ratio of at least about 50:50 and is formulated without the addition of inert solids;
- wherein the drilling fluid with the hydrophobic amine additive, when compared to the drilling fluid without the hydrophobic amine additive, restricts the increase in plastic viscosity to 60% or less and has a characteristic selected from the group consisting of:
- an increased yield point;
- an increased low shear yield point;
- an increased gel strength;
- and any combination thereof.
A method for drilling in a high temperature subterranean formation comprising providing or using in the drilling an invert emulsion drilling fluid having a mud weight in the range of about 9 ppg to about 18 ppg, wherein the drilling fluid comprises a continuous oleaginous phase and a discontinous non-oleaginous phase in an oil:water ratio in the range of about 50:50 to about 95:5, and a rheology modifier comprising a C36 fatty dimer diamine having the following molecular structure:
- wherein the drilling fluid with the hydrophobic amine additive, when compared to the drilling fluid without the hydrophobic amine additive, restricts the increase in plastic viscosity to 60% or less and has a characteristic selected from the group consisting of:
- an increased yield point;
- an increased low shear yield point;
- an increased gel strength;
- and any combination thereof.
Dependencies are inferred from the claim text.