Cementing plug

Patent metadata

Field	Value
Publication number	US-10808496-B2
Application number	US-201815864716-A
Country	US
Kind code	B2
Filing date	Jan 8, 2018
Priority date	Apr 28, 2017
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

The present disclosure relates to a cementing plug comprising a first plug body (bottom plug), a second plug body (top plug), and a plurality of cleaning portions. The first plug body comprises: a first body provided therein with a chamber opening towards a lower end thereof, and an upper end of the first body being provided with a pressure portion; and an anti-rotation portion provided on an inner wall of the first body, and capable of being connected to slurry entering the chamber to limit a rotation of the first plug body. The second plug body comprises a second body. The plurality of cleaning portions is provided on outer sidewalls of the first body and the second body along a length direction thereof, for scraping off residuals (mud cake) on an inner wall of a casing.

First claim

The invention claimed is:

1. A cementing plug, comprising a first plug body, a second plug body, and at least two cleaning portions;
wherein the first plug body comprises:
a first body provided therein with a chamber opening towards a lower end thereof, an upper end of the first body being provided with a pressure portion, which fractures when subjected to a pressure larger than a predetermined value so that the chamber is in communication with the upper end of the first body; and
an anti-rotation portion provided on an inner wall of the first body, and capable of being connected to slurry entering the chamber so as to limit rotation of the first plug body;
the first body comprises a first reinforcing member made of a hard material, located in the chamber and fixedly connected to the inner wall of the first body, and the anti-rotation portion is provided on an inner wall of the first reinforcing member;
wherein the second plug body comprises a second body having a lower end connectable to the upper end of the first body, so as to block an upper end of the chamber; and
wherein the at least two cleaning portions are provided on outer sidewalls of the first body and the second body, respectively, for scraping off residuals on an inner wall of a casing, the cleaning portions are plural and provided on the outer sidewalls of the first body and the second body, respectively, along a length direction thereof, wherein the cleaning portion comprises:
at least one first protuberance extending inclinedly upwards relative to a horizontal plane, the first protuberance is provided along a peripheral direction in a ring shape;
at least one second protuberance extending inclinedly downwards relative to the horizontal plane, the second protuberances are plural and provided along the peripheral direction at intervals, the second protuberances on the cleaning portions adjacent to each other in a longitudinal direction are alternatively provided.

2. The cementing plug according to claim 1 , wherein at least part of the second protuberances provided on the first body are projected as a ring shape in the longitudinal direction; and
at least part of the second protuberance provided on the second body are projected as a ring shape in the longitudinal direction.

3. The cementing plug according to claim 1 , wherein the number of the cleaning portions provided on the first body and/or the second body is three.

4. The cementing plug according to claim 1 , wherein the anti-rotation portion comprises at least one rib provided to extend in a length direction of the first reinforcing member.

5. The cementing plug according to claim 4 , wherein the first reinforcing member is tubular, the number of the ribs is three, and the ribs are symmetrically provided with respect to an axial direction of the first reinforcing member.

6. The cementing plug according to claim 1 , wherein a lower end of the second body is provided with a guiding portion, and an upper end of the first body is provided with a matching portion matched with the guiding portion of the second body.

7. The cementing plug according to claim 1 , wherein an angle between an extending direction of the first protuberance and an extending direction of the second protuberance is larger than 90 degrees and smaller than 180 degrees.

8. The cementing plug according to claim 1 , wherein longitudinal cross-sections of the first protuberance and the second protuberance are wing-shaped.

9. The cementing plug according to claim 1 , wherein the cleaning portion connected to the first body is integrally formed with the first body, and the cleaning portion connected to the second body is integrally formed with the second body.

10. The cementing plug according to claim 1 , wherein the second body further comprises a second reinforcing member made of a metal material and provided in the second body.

11. The cementing plug according to claim 1 , wherein one end of the first protuberance is connected to the outer sidewall of the first body and/or the second body, and one end of the second protuberance is connected to a lower side surface of the first protuberance.

12. The cementing plug according to claim 1 , wherein one end of the first protuberance is connected to the outer sidewall of the first body and/or the second body, and one end of the second protuberance is connected to the outer sidewall of the first body and/or the second body.

13. The cementing plug according to claim 1 , wherein one end of the second protuberance is connected to the outer sidewall of the first body and/or the second body, and one end of the first protuberance is connected to an upper side surface of the second protuberance.

Assignees

• China Nat Petroleum Corp
• Cnpc Eng Tech Res & Dev Co Ltd
• Beijing Petroleum Machinery Co

Inventors

• Zhang Hongying
• Wang Na
• Huang Yanfu
• Shi Lin
• Yu Ping

Classifications

• E21B33/167 Primary

  Cementing plugs provided with anti-rotation mechanisms, e.g. for easier drill-out · CPC title

• E21B33/13 Primary

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title

• E21B37/02

  Scrapers specially adapted therefor · CPC title

• E21B33/134 Primary

  Bridging plugs · CPC title

• E21B33/16

  using plugs for isolating cement charge; Plugs therefor {(stage cementing E21B33/146; spacer compositions C09K8/424)} · CPC title