Casing wiping dart with filtering layer

• US 7,673,688 B1
• Filed: 09/09/2008
• Issued: 03/09/2010
• Est. Priority Date: 09/09/2008
• Status: Expired due to Fees

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Jones, Desmond, Fears, Brett, Webb, Earl, Szarka, David
• Primary Examiner(s): Neuder; William P
• Application Number:
  US12/207,002
• Publication Number:
  US 20100059228A1
• Time in Patent Office: 546 Days
• Field of Search: 166/152, 166/153, 166/154, 166/311
• US Class Current: 166/311
• CPC Class Codes: E21B 33/08 Wipers; Oil savers
• CPC Class Codes: E21B 33/16 using plugs for isolating cement charge; Plugs therefor stage cementing E21B33/146; spacer compositions C09K8/424

Abstract

A dart may include a foam body, a filtering material at least partially covering the foam body, and a mandrel. The foam body may surround the mandrel.

Claims

1. A dart comprising:

a foam body;

a filtering material at least partially covering the foam body; and

a mandrel;

wherein the foam body surrounds the mandrel.

2. The dart of claim 1, further comprising a nosepiece at a leading end of the dart.

3. The dart of claim 1, wherein the filtering material comprises multiple layers.

4. The dart of claim 3, wherein an outermost of the multiple layers filters large solids and an inner layer filters small solids.

5. The dart of claim 1, wherein after the foam body has passed through a restriction, the filtering material cleans at least a portion of solids out of a fluid as it enters the foam body.

6. The dart of claim 1, wherein the dart is constructed of drillable material.

7. The dart of claim 1, wherein the mandrel is constructed of drillable material.

8. The dart of claim 7, wherein the drillable material is selected from the group consisting of:

aluminum, plastic, brass, a phenolic, a high-strength thermoplastic, glass, and a composite.

9. The dart of claim 1, wherein the foam body is constructed of a material selected from the group consisting of:

natural rubber, nitrile rubber, styrene butadiene rubber, and polyurethane.

10. A method of cleaning a tubular string comprising:

introducing a dart having a foam body at least partially covered by a filtering material into the tubular string;

moving the dart through the tubular string toward a restriction;

allowing the dart to compress radially to move through the restriction; and

allowing the dart to expand radially to maintain contact with the tubular string after passing through the restriction.

11. The method of claim 10, further comprising:

allowing the filtering material to clean at least a portion of solids out of a fluid as it enters the foam body to radially expand the dart.