Engineering plastic / inorganic fiber blends as lost circulation materials

Patent metadata

Field	Value
Publication number	US-9366098-B2
Application number	US-201314375835-A
Country	US
Kind code	B2
Filing date	Jan 24, 2013
Priority date	Feb 2, 2012
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A method for reducing lost circulation in drilling wells employs composite materials containing an engineering thermoplastic polymer and mineral fibers. Optionally the composites may also include other components such as calcium carbonate and blending agents.

First claim

What is claimed:

1. A method for reducing lost circulation of a fluid in a subterranean formation; said method comprising contacting the subterranean formation with a mixture of the fluid and a lost circulation material; wherein the lost circulation material comprises composite particles; wherein the composite particles comprise one or more engineering thermoplastic polymers, and one or more inorganic fibers; wherein the one or more engineering thermoplastic polymers are between about ten percent and about seventy percent of the lost circulation material by mass; wherein the one or more inorganic fibers are between about ten percent and about seventy percent of the lost circulation material by mass; and wherein the engineering thermoplastic polymer is a matrix that binds together the components of the lost circulation material into composite particles.

2. The method of claim 1 , wherein the one or more engineering thermoplastic polymers are selected from the group consisting of polycarbonates, polyamides, polybutylene terephthalate, polyethylene terephthalate, polyphenylene oxide, polyetherketone, polyetheretherketone, polyimides, polyphenylene sulfide, and mixtures and copolymers thereof.

3. The method of claim 2 , wherein the one or more engineering thermoplastic polymers comprise recycled commercial engineering plastic products.

4. The method of claim 1 , wherein the one or more inorganic fibers are selected from the group consisting of basalt fibers, glass fibers, ceramic fibers, rock wool fibers, and mixtures thereof.

5. The method of claim 4 , wherein the one or more inorganic fibers comprise basalt fibers.

6. The method of claim 1 , wherein the composite particles additionally comprise one or more minerals.

7. The method of claim 6 , wherein the one or more minerals are selected from the group consisting of calcium carbonate, mica, talc, ceramics, and mixtures thereof.

8. The method of claim 7 , wherein the one or more minerals comprise precipitated calcium carbonate.

9. The method of claim 1 , wherein the composite particles additionally comprise one or more blending agents.

10. The method of claim 9 , wherein the blending agents are selected from the group consisting of silanes, other monomeric silicon compounds, and monoalkoxy titanates.

11. The method of claim 1 , wherein the particle size distribution of the lost circulation material is selected to minimize the amount of lost circulation for the sizes of cracks and fissures characteristic of a chosen subterranean formation.

12. The method of claim 1 , wherein the composite particles are admixed with one or more other thermally stable, lost circulation materials; wherein at least some of the other lost circulation materials do not comprise a composite material.

13. The method of claim 12 , wherein the one or more other lost circulation materials are selected from the group consisting of basalt fibers, calcium carbonate, graphite, and thermoset polymers.

14. The method of claim 1 , wherein the fluid comprises a drilling fluid; and wherein said method reduces losses of the drilling fluid.

15. The method of claim 1 , wherein the fluid comprises a cement fluid injected into a subterranean formation during a cementing operation; and wherein said method reduces losses of the cement fluid, and thereby strengthens the cured cement.

Assignees

• Wu Qinglin
• Univ Louisiana State

Inventors

• Wu Qinglin

Classifications

• C09K8/508

  macromolecular compounds {(C09K8/512 takes precedence)} · CPC title

• C09K8/5045

  containing inorganic compounds · CPC title

• E21B21/00 Primary

  Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B31/03) · CPC title

• C09K8/487 Primary

  Fluid loss control additives; Additives for reducing or preventing circulation loss · CPC title

• C09K2208/08

  Fiber-containing well treatment fluids · CPC title