Aphron-containing well drilling and servicing fluids

Patent 6390208 Issued on May 21, 2002. Estimated Expiration Date:

May 7, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventor

Brookey, Tommy F.

Application

No. 320375 filed on 05/07/1999

US Classes:

175/72, Prevention of lost circulation or caving166/292Using specific materials

Examiners

Primary: Bagnell, David
Assistant: Dougherty, Jennifer R.

Attorney, Agent or Firm

Conley, Rose & Tayon, P.C.

International Classes

E21B 007/18
E21B 033/13

Abstract

The invention provides a method and fluid for drilling or servicing a well in a subterranean formation containing lost circulation zones or depleted, low pressure reservoirs. The fluid comprises an aqueous liquid having dispersed therein a polymer which increases the low shear rate viscosity of the fluid to the extent that the thixotropic index of the fluid is at least about 10 and a surfactant, and wherein the fluid contains less than about 15% by volume of aphrons preferably generated by the turbulence and pressure drop as the fluid exits the drill bit in the vicinity of the formation. The method of drilling a wellbore in a subterranean formation comprises continuously circulating, while drilling, such a drilling fluid.

Other References

Felix Sebba, "Colloidal Gas Aphrons", 1987, Foams and Biliquid Foams-Aphrons, pp. 62-69.
Article entitled "Underbalanced Drilling Manual," Published by Gas Research Institute, GRI Ref. No. GRI-97/0236, 1997
Article entitled "Treatability of Water-based Drilling Fluids Using Colloidal Gas Aphrons," D. Roy, K.T. Valsaraj, and V.J. Amedee, Departments of Civil Engineering and Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803, vol. 5, No. 1, Mar. 1992
SPE 39589 "Microbubbles: New Aphron Drill-in Fluid Technique Reduces Formation Damage in Horizontal Wells," Tom Brookey, SPE, ActiSystems, Inc., Feb. 18-19, 1998
Article entitled "Drill-in Fluids Improve High-angle Well Production," Petroleum Engineer Intn'l., Mar. 1995
Article entitled "Microbubbles: Generation and Interaction With Colloid Particles," J.B. Melville and E. Matijevic, Institute of Colloid and Surface Science and Department of Chemistry, Clarkson College of Technology, Potsdam, New York, 1975
Article entitled "Separation of Organic Dyes From Wastewater by Using Colloidal Gas Aphrons," D. Roy, K.T. Valsarlj, and S.A. Kottai, Marcel Dekker, Inc., 1992
Article entitled "Hidraulica Forajului" (with Translation), Oct. 26, 1982
Article entitled "Hidraulica Forajului" (undated)
H1000, Patel et al, Filed Aug. 16, 1990, Published Dec. 3, 1991
H837, Peiffer et al, Filed Jul. 5 1989, Published Nov. 6, 199