Drilling lost circulation material
AssigneeSchlumberger Technology Corporation
InventorJaleh Ghassemzadeh
Life of this patent
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Abstract
An engineered composition for reducing lost circulation in a well includes a mixture of coarse, medium and optional fine particles, and a blend of long fibers and short fibers. The long fibers are rigid and the short fibers are flexible. The long fibers form a tridimensional mat or net in the lost-circulation pathway that traps the mixture of particles and short flexible fibers to form a mud cake. The mixture of particles and blend of fibers may be added to water based and oil-based drilling fluids. The composition, size, and concentration of each component of the mixture of particles and blend of fibers may be fine-tuned for each application.
Claims20
A method for reducing lost circulation in a well comprising:
- (i) adding to a drilling fluid a composition comprising:
- (1) a mixture of coarse particles having an average particle size between 300 and 1200 μm, medium particles having an average particle size between 20 and 150 μm and optionally fine particles having an average particle size between 5 and 15 μm;
- and
- (2) a blend of long fibers having an average length between 8 and 15 mm, and short fibers having an average length between 1 and 8 mm;
- and
- (ii) circulating the drilling fluid in the well.
Dependencies are inferred from the claim text.