The field of the invention is rotary tubular scrapers/mills/hones and more particularly tools with pivotally mounted arms to allow the tool to pass through smaller tubing to scrape or hone a larger tubular.
Tubular cleaning up is a common procedure in situations such as after cementing but it also is used in other contexts. Most typically the tubular is casing and in applications where the size of the casing declines as the hole gets deeper. In those instances the scrapers typically comprise one or more rounded elements supported on a mandrel that is rotated either from the surface or with a downhole motor. The elements can be brushes that are spring biased outwardly against the tubular wall. The elements are supported from the mandrel against the torsional loads that occur during the scraping operation. Some examples of such scrapers are U.S. Pat. Nos. 6,343,648; 4,809,779; 6,152,221 and 6,484,802. Some designs involve linkages that extend opposed ends of scraping elements such as WO2001066907 to allow scraping of different size casing in the same trip. Also of general interest in the area of scrapers are US20060201670 and US20090313781 which illustrates a hand held scraper with a spring loaded blade.
Situations arise where the scraping needs to be done with a drill or production string in the borehole. In those instances the tool has to pass through a smaller dimension and then has to be deployed in significantly larger tubulars. In the past cutting tools that have pivotally mounted arms that are hydraulically extended have been used for descaling or scraping the interior wall of a surrounding larger tubular after being run in through a smaller tubular. These devices were modified tubular cutters where the same pivoting blades were used but different end treatments were applied to accomplish the objective of cleaning or descaling rather than cutting through the tubular. It was determined that such modified blades fitted on line cutting tool bodies were marginally effective for cleaning or descaling. The reason was that there was very limited contact are at the cantilevered ends of the blades to accomplish that function. The present invention seeks to improve the cleaning ability of such a tool and addresses the issue with an articulated lower end for the blades so that when the blades are extended to a preferred angle of about 45 degrees, although other angles are contemplated, the lower ends are articulated into a near parallel orientation to the tubular wall so that the contact area is enhanced as the tool cleans while being rotated. The envisioned tool has other applications such as for honing the inside wall of a tubular, milling or cleaning around objects in the tubular in a direction moving toward the tubular axis or using the tool as a latch tool to anchor itself or attached tools or to move other tools within the tubular. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.
A tubular cleaning tool can be delivered through tubing and then hydraulically or mechanically actuated to rotate blades about respective pivot location into approximately a 45 degree orientation for commencement of tool rotation and cleaning a larger tubular that is below. Each of the blades has a cantilevered distal end that further features at least one articulated link. The outer periphery of the articulated distal segment has hard facing to enhance the cleaning effect and to reduce blade wear. The remainder of the blade outer surface can also have hard facing for similar reasons. The distal segment can be biased toward the surrounding tubular when the blades extend to put the segment in the needed orientation for cleaning. Alternative uses are envisioned such as honing or milling in the direction toward a tubular axis or latching or shifting tools already within the tubular.
Dashed line 10 is intended to schematically illustrate a housing that has an optional travel stop when the at least one blade or knife upper arm 12 is powered or released to rotate about pivot 14 outwardly in the direction of arrow 16. Upper arm 12 is attached to a lower arm 18 that is pivotally mounted at pivot 20 to allow the lower arm 18 to rotate relative to upper arm 12. Hard facing 22 is on an exterior surface 24 of the lower arm 18. Exterior surface 24 can be curved to conform to the inside wall shape of tubular 26. In the extended position the lower arm 18 is in substantial alignment with the inside wall of a surrounding tubular 26 that is schematically illustrated in
While a single blade assembly of upper and lower blades 12 and 18 are illustrated the housing 10 preferably has a plurality of such assemblies that can be all the same or different. The amount of radial extension from the housing 10 can be the same for all assemblies or different. Additionally there can be axially spaced rings of assemblies that have the same or different abilities to extend radially.
Alternative applications are envisioned. For example, 22 can be hard facing or/and carbide so that on contact with the wall of tubular 26 the inside surface can be not only cleaned of debris but can be honed to a predetermined dimension that is set by the travel stops on the housing 10 and/or 28 on the lower blade 18. Alternatively or additionally a milling profile 36 can be placed on the inside or/and lower portions of the lower blade 18 as shown in
The tool can clean a surrounding string from within an inner string after an inner string has been severed to facilitate a plug and abandon procedure.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below: