GB2345073A

GB2345073A - Pneumatic retractable drill pipe wiper

Info

Publication number: GB2345073A
Application number: GB9828243A
Authority: GB
Inventors: John Goodwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-12-22
Filing date: 1998-12-22
Publication date: 2000-06-28
Also published as: GB9828243D0

Abstract

A retractable drill pipe wiper comprises pneumatic rams 5 pivotally mounted on supports 3, wiper holders 7, and rubber wipers 8, each wiper having cut-out radii to suit 127mm (5 inch) and 89mm (3.5 inch) diameter drill pipe. Eccentricity of the drill pipe may be catered for by having low pressure in the pneumatic rams, residual stroke remaining in the pneumatic rams and a slotted guide in the wiper holders.

Description

PNEUMATIC RETRACTABLE DRILL PIPE WIPER This invention relates to a Pneumatic Operated Retractable Drill Pipe Wiper.

A device to wipe the drill pipe of the drilling mud, the circulating fluid used during the drilling of oil/gas wells.

Drill Pipe Wipers currently in use are of a one piece circular rubber mat that has a hole through the centre to fit the size of drill pipe being used i. e. 127mm (5 inch) or 89mm (3.5 inch) diameter.

This circular rubber mat is commonly known throughout the drilling industry as a'doughnut'.

Obviously when the centre hole has worn and there is no appreciable wiping of drilling mud the doughnut wiper is discarded and a new one fitted.

Another important point is that when the doughnut is in position on top of the bell nipple 1 (Fig 1) the drilling personnel cannot readily observe the level of circulating mud in bell nipple. What they have to do is to climb down from the drill floor and physically lift the doughnut.

This is a somewhat precarious and time consuming activity.

With the Pneumatic Retractable Wiper, the wiper can be can be quickly and easily stroked back.

According to the present invention there is provided a pneumatic operated split rubber drill pipe wiper.

Fig 1 (Drawing 1/7) shows the a side elevation of the assembly as it would be mounted on the bell nipple item 1 with both the pneumatic rams in the closed position and both split rubber wipers item 8 tight around the drill pipe item 2 The controls for the pneumatic rams will be situated on the drill floor with easy access by drilling personnel By having the rubber wiper moulded in a square it can be made to have the use of four different positions, therefore as wear occurs in the active wipers both wipers can be relocated to present a new hole.

It is envisaged that the wipers would have three 127MM and one 89MM considering that 127mm drill pipe is commonly in use. item 8 (Drawing 2/7) The pneumatic rams, item 5 (Drawing 3/7) will be 315 mm stroke 75mm bore and a 50mm dia shaft extension with 25 mm threaded end.

The pneumatic rams will be operated by a supply of compressed air regulated to 10 psi this will allow the piston to have some resilience to compensate for any eccentricity of the drill pipe within the bell nipple.

The pneumatic rams will be set in position so as to have a 30mm remaining stroke when the rubber wipers are active around the drill pipe, this will allow the pneumatic rams to follow the eccentricty of the drill pipe.

The pneumatic rams are secured to the wiper holders item 7 (Drawing 5/7) by threaded end of the shaft extension and the 25mm nut.

The pneumatic rams and wiper holders are held in position on support item 3 (Drawing 4/7) by the pivot bolt assembly item 6 (Drawing 6/7) through the trunnion end of the pneumatic ram and by the slotted guide plate on item 5 (Drawing 5/7) The guide slot in support item 3 (Drawing 4/7) will be wide enough to allow some lateral movement to accommodate any eccentricity of the drill pipe within the bell nipple.

The supports item 3 (Drawing 4/7) will be secured to the bell nipple by bolting to the gusset plates item 4 (Drawing 1/7) which will be permanent welded fixtures on the bell nipple.

The rubber wipers item 8 (Drawing 2/7) are shown kissing together to form the 127mm (5 inch) diameter hole around the drill pipe.

It is envisaged the rubber wipers will be 560mm x 560mm and 50 mm thick.

The rubber wipers will be secured in the wiper holders item 7 (Drawing 5/7) by a cap head plastic pin item 9 (Drawing 7/7) passing through the holes in the wiper holder and rubber wipers (see side elevation of assembly Drawing 1/7) Plastic material is utilized for this pin in the event that the pins falls into the well it can be readily ground away by the drill bit.

Claims

CLAIMS 1. A Pneumatic Retractable Drill Pipe Wiper comprising of fabricated supports, pneumatic rams with pivotal locator, a fabricated wiper holder with a support and guide and rubber wipers with cut-out radii to suit 127mm (5 inch) and 89mm (3.5 inch) diameter drill pipe.
2. A Pneumatic Retactable Drill Pipe Wiper as Claimed in Claim 1 with the capability of accepting eccentricty of the drill pipe within the bell nipple by provision of pivoted pneumatic rams, low air pressure in the pneumatic rams, residual stroke remaining in pneumatic rams and a wide slotted guide in the wiper holder.
3. A Pneumatic Retractable Drill Pipe Wiper as Claimed in Claimi or Claim 2 whereas the Rubber Wipers are so designed so as to have the capability of four positions to accommodate wear and two drill pipe sizes.

It will also be possible to re-dress two opposite faces of the Rubber Wiper by removing no more than 12mm and re-cutting radially the cut-outs for 127mm and/or 89mm diameter drill pipe.