Composite micro-coil for downhole chemical delivery

• US 8,607,868 B2
• Filed: 08/16/2010
• Issued: 12/17/2013
• Est. Priority Date: 08/14/2009
• Status: Expired due to Fees

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Varkey, Joseph, Liu, Zhanke, Gambier, Philippe
• Primary Examiner(s): COY, NICOLE A
• Application Number:
  US12/856,776
• Publication Number:
  US 20110042090A1
• Time in Patent Office: 1,219 Days
• Field of Search: 166/305.1, 166/242.1, 166/242.2, 166/242.3, 166/77.2, 138/143, 138/139
• US Class Current: 166/305.1
• CPC Class Codes: E21B 17/20 Flexible or articulated drilling pipes , e.g. flexible or articulated rods, pipes or cables
• CPC Class Codes: E21B 43/25 Methods for stimulating production by vibrating earth formations E21B43/003
• CPC Class Codes: F16L 9/147 comprising only layers of metal and plastics with or without reinforcement

Abstract

A technique utilizes micro-coil which is formed as a composite to enable use at substantial depths and/or with substantial flow rates. The micro-coil is formed as a tubing with a multi-layered tubing wall. The composite tubing wall provides substantial strength and longevity which allows deployment of the micro-coil in a much wider variety of well treatment applications, such as applications having substantial flow rates and/or applications at substantial well depths.

Claims

1. A method of delivering chemicals downhole, comprising:

providing a composite micro-coil formed as a tubing having a tubing wall with a metal internal layer, a metal external layer, and a non-metal layer between the metal internal layer and the metal external layer;

providing coiled tubing and disposing the coiled tubing downhole into a wellbore;

conveying the composite micro-coil downhole into the wellbore, the composite micro-coil disposed in a one of an interior of the coiled tubing and an exterior of the coiled tubing; and

delivering a chemical downhole along an interior of the composite micro-coil.

2. The method as recited in claim 1, wherein the metal internal layer comprises stainless steel.

3. The method as recited in claim 1, wherein the metal external layer comprises a nickel-iron-chromium alloy.

4. The method as recited in claim 1, wherein the non-metal layer comprises a composite layer.

5. The method as recited in claim 1, wherein the non-metal layer comprises a carbon-epoxy layer.

6. The method as recited in claim 1, wherein the non-metal layer comprises a composite layer having a fiber content of about 20 to about 75 percent.

7. The method as recited in claim 1, wherein the metal internal layer forms a conductive path and the non-metal layer is formed of an insulation material.

8. The method as recited in claim 1, further comprising placing a bonding layer between the non-metal layer and at least one of the metal internal layer and the metal external layer.

9. The method as recited in claim 1, further comprising placing a thermoplastic or thermoset layer between the non-metal layer and at least one of the metal internal layer and the metal external layer.

10. The method as recited in claim 1, further comprising placing an thermoplastic or thermoset jacket along an exterior of the metal external layer.

11. The method as recited in claim 1, further comprising performing a well treatment or stimulation application with the coiled tubing, wherein the chemical delivered along the micro-coil facilitates the well treatment or stimulation application.

12. A method for delivering chemicals downhole, comprising:

selecting a plurality of layers of different materials;

forming the plurality of layers into a micro-coil tubing such that the arrangement of layers increases a tubing strength to enable an increased flow rate of treatment fluid during a well treatment compared to a single layer metal micro-tubing;

deploying a coiled tubing and the micro-coil tubing into a wellbore, the micro-coil tubing deployed adjacent to the coiled tubing;

performing a well treatment operation with the coiled tubing; and

facilitating the well treatment operation by delivering chemicals through an internal passage of the micro-coil tubing.

13. The method as recited in claim 12, further comprising delivering a chemical treatment through the micro-coil tubing to a desired wellbore location.

14. The method as recited in claim 12, wherein forming comprises forming the micro-coil tubing with a metal internal layer, a metal external layer, and a non-metal layer between the metal internal layer and the metal external layer.

15. The method as recited in claim 14, wherein forming comprises forming the metal internal layer with a steel material.

16. The method as recited in claim 15, wherein forming comprises forming the metal external layer with an alloy.

17. The method as recited in claim 16, wherein forming comprises forming the non-metal layer as an thermoplastic or thermoset layer mixed with a fiber.

18. A system for use in a wellbore operation comprising:

a micro-coil, comprising;

inner and outer metal layers; and

a middle layer disposed between the inner and outer metal layers, wherein the middle layer comprises a composite material, wherein the outside diameter of the micro-coil is about 0.25 inches and wherein the micro-coil further defines an internal flow passage configured to deliver a chemical treatment therethrough; and

a coiled tubing comprising hydraulic fracturing equipment disposed on an end thereof for performing a hydraulic fracturing operation, the micro-coil disposed adjacent the coiled tubing during the hydraulic fracturing operation and during the delivery of the chemical treatment.

19. The system as recited in claim 18, wherein the composite material comprises a matrix material having a plurality of fibers embedded therein.

20. The system as recited in claim 19, wherein matrix material is chosen from the group consisting of epoxy, Peek, Pek, thermoplastic and a thermoset material.

21. The system as recited in claim 20, wherein the plurality of fibers are chosen from the group consisting of Carbon, Kevlar, glass, aluminum, ceramic, steel, and combinations thereof.

22. The system as recited in claim 21, wherein the inner metal layer comprises a material chosen from the group consisting of carbon steel, stainless steel, and inconel.

23. The system as recited in claim 22, wherein the outer metal layer comprises a material chosen from the group consisting of carbon steel, stainless steel, and inconel.