METHOD AND SYSTEM FOR REDUCING FRICTION IN RADIAL DRILLING AND JET DRILLING OPERATIONS

Abstract

Disclosed is a method for reducing friction in a radial drilling application. The method involves coating the interior of a deflector shoe with a lubricant. Lubrication of the deflector show can be accomplished by applying a wet lubricant to the interior of the deflector shoe or spraying a dry lubricant on the interior of the deflector shoe. The method can further include coating a hose and/or a jet nozzle, passing the hose and/or jet nozzle through the coated interior of the deflector shoe. The method can further include coating components of a milling cutter, and passing the components of the milling cutter through the coated interior of the deflector shoe. An apparatus for reducing friction in a radial drilling application is also disclosed.

Claims

1. A method for reducing friction in a radial drilling application, the method comprising: coating the interior of a deflector shoe with a dry lubricant by spraying the dry lubricant on the interior of the deflector shoe.

2. The method of claim 1, further comprising: applying a wet lubricant to the interior of the deflector shoe.

3. (canceled)

4. The method of claim 1, further comprising: coating a hose; and passing the hose through the coated interior of the deflector shoe.

5. The method of claim 1, further comprising: coating a jet nozzle; and passing jet nozzle through the coated interior of the deflector shoe.

6. The method of claim 1, further comprising: coating components of a milling cutter; and passing the components of the milling cutter through the coated interior of the deflector shoe.

7. The method of claim 1, the lubricant being selected from a group consisting of: tire shine, flouropolymer coatings; and tungsten disulfide coating.

8. (canceled)

9. (canceled)

10. (canceled)

11. A method for reducing friction in a radial drilling application, the method comprising: coating the interior of a deflector shoe with a lubricant; coating a hose; and passing the hose through the coated interior of the deflector shoe.

12. The method of claim 11, the lubricant being selected from a group consisting of: tire shine, flouropolymer coatings, and tungsten disulfide coating.

13. A method for reducing friction in a radial drilling application, the method comprising: coating the interior of a deflector shoe with a lubricant; coating a jet nozzle; and passing jet nozzle through the coated interior of the deflector shoe.

14. The method of claim 13, the lubricant being selected from a group consisting of: tire shine, flouropolymer coatings, and tungsten disulfide coating.

15. A method for reducing friction in a radial drilling application, the method comprising: coating the interior of a deflector shoe with a lubricant; coating components of a milling cutter; and passing the components of the milling cutter through the coated interior of the deflector shoe.

16. The method of claim 15, the lubricant being selected from a group consisting of: tire shine, flouropolymer coatings, and tungsten disulfide coating

17. A method for reducing friction in a radial drilling application, the method comprising: coating the interior of a deflector shoe with a lubricant, the lubricant being selected from a group consisting of: tire shine, flouropolymer coatings, and tungsten disulfide coating.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0028] FIG. 1 is a schematic illustration showing a prior art indexing deflector assembly having a deflector shoe.

[0029] FIG. 2 is a schematic illustration of a jet drilling process illustrating a jet nozzle passed through a deflector shoe.

[0030] FIG. 3 is an example of the prior art thumper nozzle subassembly as used in radial jet drilling operations.

[0031] FIG. 4 illustrates the method and system of the present invention.

[0032] FIG. 5 shows Graph 1, wherein tests results show that as the inner pressure of the hose increases, the force required to pull the hose through the shoe increases.

[0033] FIG. 6 shows Graph 2 wherein test results illustrate how the force required changes depending on different coating of the hose.

[0034] FIG. 7 shows Graph 3, wherein test results are provided when the hose is coated with Never Seez?.

DETAILED DESCRIPTION OF THE INVENTION

[0035] Referring to FIG. 4, there is shown an illustration of the system and method of the present invention. A deflector shoe 52 is associated with a casing 62. The deflector shoe 52 has an interior through which a flexible hose 54 is moved. The flexible hose 54 has a jet nozzle 64 at an end thereof. FIG. 4 also illustrates work tubing 53 having a coil tubing 56 therein. This is connected by connector 58 to the flexible hose 54. Also illustrated in FIG. 4 is a centralizer 60 which serves to position the deflector shoe within the casing 62.

[0036] The interior of the deflector shoe 52 is provided with a lubricant coating 70. As can be seen in FIG. 4, the lubricant coating 70 is provided on the interior surface of the deflecting shoe 52, and is importantly provided at contact surfaces between the flexible hose 54, jet nozzle 64 and the interior of the deflector shoe 52. The lubricant coating 70 can include a wet lubricant or a dry lubricant.

[0037] In the case of a wet lubricant, the lubricant coating 70 can be applied manually by a worker onsite or in the field. In the case of a dry lubricant, the lubricant coating is preferably sprayed on the interior of the deflector shoe 52.

[0038] In the present invention, the flexible hose 54 and jet 64 may also be coated with the same or another lubricant coating so as to further reduce friction between the components. It is also within the concept of the present invention that the components of a milling cutter can be coated with a lubricant before passing through the lubricated deflector shoe 52.

[0039] A number of different commercially available lubricants may be utilized in the system and method of the present invention, including tire shine, fluoropolymer coatings, tungsten disulfide coating and Never Seez?.

[0040] Tire shine is a range of products which use specialized polymer technology to create a gloss finish on the tire surface. Such polymer compounds are formulated to not only make tires look good (due to the gloss finish) but also to protect them from harmful UV rays, grime and other contaminants picked up on road surfaces.

[0041] The Never-Seez? product line (by BOSTIK) covers a range of anti-seize compounds to meet a wide range of anti-seize, anti-galling, and lubrication applications. Special greases are entrained with specific particulates (predominantly metallic) to protect parts even in high-temperature, high-pressure and corrosive environments, allowing parts to work longer with less wear. Not all compounds are appropriate to every application.

[0042] Experimentation by the inventors found that treatment with lubricants at the contact surfaces between the hose and the deflector shoe helped greatly decrease the force required to pull the hose through the deflector shoe. This, in turn, decreased the required propulsion force needed from the nozzle to pull the hose and the required flow rate to the nozzle itself. It was discovered that with the maximum force required to pull a 5600 p.s.i. pressurized hose through the deflector shoe reduced by 65%, from 25 lbft for the dry hose to 8 lbft for a tire shine or oil coated hose through a Never Seez? coated shoe

[0043] Experiments utilizing a combination of wet lubricants were conducted by the inventors, and are detailed below. First, a pull through shoe test was conducted. Specifically, this tested the force required to pull a pressurized hose through a shoe having different surface conditions. This test was performed to analyze how much force was required to pull a hose through a deflector shoe by varying the magnitude of the pressure with different surface conditions. The hose was laid between two steel deflector shoe pieces. The hose was pulled out at continuous rate and the maximum required force was recorded. The test was conducted with various hose conditions: (1) dry hose, (2) hose wet with water, (3) dry hose through shoe pieces coated with commercially-available lubricant, and (4) oily hose through shoe pieces coated with commercially-available lubricant. A commercially-available hose was utilized. In this test, the commercially-available lubricant was Never Seez?.

[0044] The results of the tests are shown in Graph 1 (see FIG. 5). Graph 1 illustrates that as the inner pressure of the hose increases, the force required to pull the hose through the shoe increases. The maximum applied hose pressure was 5600 p.s.i. However by lubricating the surface of the hose, the required pull force decreases about 50% from a dry hose to an oily hose and a shoe coated with commercially-available lubricant.

[0045] By reducing the friction on the hose, effectively more force can be transmitted. Further experiments were conducted with different coatings. The Graph 2 (see FIG. 6) illustrates three additional conditions, namely (5) tire shine-coated hose through deflector shoe, (6) tire shine/oil coated hose through deflector shoe, and (7) tire shine/oil coated hose through Never Seez? coated shoe. It was discovered that the maximum required force to pull a 5600 p.s.i. hose through the deflector shoe drops from 8.4 lbft for tires for condition (7), namely tire shine/oil coated hose through Never Seez? coated could shoe.

[0046] Coating the hose with Never Seez? also resulted in differences in the average force required to pull a hose through the deflector shoe, as is illustrated in Graph 3 (see FIG. 7).

[0047] The experiments detailed above were conducted using a wet lubricant, which can be manually applied. While the results are very promising, it is possible that a dry lubricant would be more likely to adhere to the interior of the deflector shoe over time. As such, a number of dry lubricants can also be used within the concept of the present invention. These dry lubricants are preferably sprayed on and allowed to dry, and can also be used for longer periods of time. The inventors expect similar results from the dry lubricant in terms of differences in pulling force.

[0048] The method and system of the present invention allows for greatly reduced friction between drilling components and the deflector shoe. This, in turn, increases the useful life of the components associated with these operations. Additionally, the reduced friction allows for a reduction in the power requirements of equipment used to run the tools in the drilling operations, contributing to a reduction in costs association with these operations.

[0049] The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made is the scope of the present invention without departing from the true spirit of the invention.