Methods of using reversible phase oil based drilling fluid
AssigneeM-I L.L.C.
InventorArvind D. Patel
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Abstract
Invert emulsion compositions including an oleaginous, a non-oleaginous and an amine surfactant that are useful in the oil and gas well drilling art are disclosed. The amine surfactant is selected so that the invert emulsion can be converted form a water-in-oil type emulsion to a oil-in-water type emulsion upon the protonation of the amine surfactant. Deprotonation of the amine surfactant reverses the conversion. This solution also permits the conversion of oil-wet solids in the fluid into water-wet solids.
Claims8
A method of electrically logging a subterranean well, the method comprising:
- a) drilling the subterranean well with an invert emulsion drilling fluid, wherein said fluid includes:
- an oleaginous fluid;
- a non-oleaginous fluid;
- and an amine surfactant having the structure
- wherein R is a C12-C22 aliphatic hydrocarbon;
- R′ is an independently selectable from hydrogen or C1 to C3 alkyl;
- A is NH or O, and 1≦x+y≦3;
- b) adding acid to the invert emulsion drilling fluid in a sufficient amount to reverse the filtercake solids from being oil-wet to being water-wet;
- and
- c) electrically logging said well.
A method of electrically logging a subterranean well, the method comprising:
- a) drilling the subterranean well with an invert emulsion drilling fluid, wherein said fluid includes:
- an oleaginous fluid;
- a non-oleaginous fluid;
- and an amine surfactant having the structure
- wherein R is a C12-C22 aliphatic hydrocarbon;
- R′ is an independently selectable from hydrogen or C1 to C3 alkyl;
- A is NH or O, and 1≦x+y≦3;
- b) acidifying the invert emulsion drilling fluid until the filtercake solids are reversed from being oil-wet to being water-wet;
- and
- c) electrically logging said well.
Dependencies are inferred from the claim text.