Lost circulation material for sealing permeable formations
AssigneePhillips Petroleum Company
InventorElmer E. Clear
Life of this patent
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Abstract
A composition of matter and a method of making is provided for preparing slurries to seal permeable earth formations encountered in the drilling of wells. The composition of matter comprises finely divided paper, diatomaceous earth, and in a further embodiment, lime. Slurries of the composition of matter can be prepared using fresh water or salt water to form a water-based lost circulation fluid, or using oil to form an oil-based lost circulation fluid. A slug of the slurry is spotted at the locus of the permeable formation and defluidized to form a formation seal on which a mud sheath is then deposited.
Claims10
A composition of matter for sealing permeable formations comprising diatomaceous earth and a suspending agent wherein:
- the suspending agent consisting of finely divided paper present in an amount in the range of about 2 to about 30 percent by weight of said mixture said diatomaceous earth being present in an amount of from about 70 to about 98 percent by weight of said mixture.
A composition of matter for sealing permeable formations comprising a mixture comprising a suspending agent, diatomaceous earth, and lime wherein the suspending agent consists of finely divided paper in an amount in the amount of about 2 to about 30 percent by weight of the mixture effective to suspend the diatomaceous earth, and, if present, other lost circulation materials, when the mixture is used in lost circulation material fluids, said diatomaceous earth being present in an amount of from about 55 to about 98 percent by weight of the mixture and said lime is present in an amount of from about 0 to about 15 percent by weight of said mixture.
A composition of matter as in claim 5 wherein:
- said finely divided paper comprises in the range of about 4 to about 16 percent by weight of said mixture;
- said diatomaceous earth comprises in the range of about 72 to about 90 percent by weight of said mixture;
- and
- said lime comprises in the range of about 6 to about 12 percent by weight of said mixture.
Dependencies are inferred from the claim text.