The field of the invention is barriers that can be positioned in a borehole to aid a treatment involving pressurized fluid and more particularly a barrier that is formed in place from a disintegrating material using a variable diameter swage to create a landing location for an obstructing object in aid of the pressure treatment of a surrounding formation.
Well treatments such as fracturing are frequently performed using a series of plugs that have a passage through them that is surrounded by a ball seat. A repeating pattern of setting a plug and releasing from the plug with a perforating gun to fire the gun and then to either remove the gun and drop a ball or to drop a ball while the gun is still in the hole with the final step using pressure against the seated ball in the plug for the treatment of a part of the adjacent formation. Typically a bottom up direction is employed of this pattern as further portions of the surrounding formation are treated. When the entire formation is treated the plugs need to be removed before production or injection begins. This can be done by milling out all the plug which can be time consuming. Parts of the plugs can be made of disintegrating materials but the remaining components still need either to be drilled out, pushed to bottom or circulated out. The plugs themselves are costly to produce and present some inherent risks that they will not properly set. Some jobs require a large number of plugs regardless of whether they are all set initially and then sequentially sealed off with progressively larger balls or are run in and set sequentially.
Also relevant in general to the subject of barriers that disappear or degrade are U.S. Pat. Nos. 8,794,335; 8,668,119; 8,342,240; 8,297,364; 7,661,481; 7,762,342; 7,461,699; 7,451,815; 5,103,911; 3,216,497; 2,261,292; 2,214,226; 20130299185 and 2014/0027127. Of particular significance is 20140014339 FIG. 11 which shows a tool that sets a disintegrating member that comes equipped with a ball seat.
The present invention is a departure from these known techniques in that instead of the plugs it encompasses delivery of a clad with a variable diameter swage to allow in essence the creation of a passage with a surrounding seat to accept an object against which pressure can be held to perform the treating operation. The clad is made of a disintegrating material such as a controlled electrolytic material so that after a time or with exposure to heat or well fluids to name some examples, the clad simply disintegrates. One trip operation can be accomplished with the running in of a bottom hole assembly that has the variable swage and the actuation device to move and build the swage after some expansion but to also support a gun and a ball dropping device so that the multi-diameter expansion can take place and the bottom hole assembly raised further after the swage clears the clad so that the gun can be operated to create perforations. The bottom hole assembly can then be retrieved and the ball dropped to close off the clad so that a treatment operation can then immediately begin into the perforations. This can be repeated as many times as needed to cover the entire interval of the formation. Over time the clads and balls released onto the clads simply disintegrate. Those skilled in the art will appreciate other aspects of the present invention from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing the full scope of the invention is to be determined from the claims.
A clad is expanded with a variable swage or other ways to create a seat for an object to obstruct the passage therethrough while at the same time expanding at least a part of the clad into a surrounding tubular for support and sealing. The exterior of the clad can have grit to enhance the grip. A perforating gun can be delivered in the same trip with the clad. After the swage passes through the clad the gun is positioned and fired, the bottom hole assembly is retrieved and the ball is dropped from the surface onto the seat formed in the clad with expansion or with some other means. A treating operation against the clad and into the surrounding formation can then take place. The process can be repeated preferably in a bottom up direction until the formation is fully treated. The clads and objects landed on the clads disintegrate with time or borehole exposure.
Referring to
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As shown in
While the above described operations have focused on locating a single clad in a borehole combined with perforating and conduction a pressure operation against a seated ball, those skilled in the art will appreciate that the process can be repeated as many times as necessary and preferably in a bottom up direction to fully treat an entire formation in increments. The perforating gun is preferably located above the variable swage. While some initial expansion is preferred in zone 32, the clad 22 can be top supported adjacent device 24 so that as an option there is no expansion of the clad 22 in zone 32 until the point where the variable swage is built within the clad 22 as shown in
Those skilled in the art can appreciate the substantial cost savings from using the described method. The clads 22 are significantly cheaper than the more complex plugs that they replace and the clads 22 and ball 20 are fully disintegrating so as to return the tubular 30 to its original drift dimension after the disintegration and saving the time for any interventions such as for milling non-disintegrating components of plugs that were previously used.
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: