Patent Application
20160312560
The field of the invention is completion operation where the completion equipment needs to be removed by milling and sliding sleeve or other types of valves functioned to the open position prior to production or injection.
In several treatment applications, notably fracturing, there are a series of ball seats used to sequentially frack portions of a producing interval. Typically these ball seats take progressively larger balls for zone isolation and pressure is applied against each seated ball in sequence going bottom up as progressively larger balls are dropped. At the end of the treatment, there is a need to remove the ball seats, a process that is usually accomplished by a separate trip with a mill attached to a downhole motor such as a progressing cavity motor of a known design. The cuttings are circulated out using the flow that initially drives the downhole motor. In some applications that use multiple plugs all the plugs can be milled out in a separate milling trip as shown in US 2013/0319669. In some applications where there are sleeves that are operated with known shifting tools, the milling trip is a separate trip from the trip where the shifting tool is used to open the sleeves for subsequent production or injection. This is illustrated in US 2013/0062066.
The present invention seeks to make the treatment process more efficient by saving rig time and shortening operations. Along those lines a bottom hole assembly (BHA) is proposed that will combine the milling and shifting of sleeves into a single trip rather than the separate trips that were required in the past. The sleeve shifter tool can be a part of the BHA and preferably mounted uphole from the downhole motor that drives the mill. The shifting tool is maintained retracted toward the mandrel of the BHA when the milling is undertaken and is then deployed to selectively grab, shift and release from the sliding sleeves as the BHA is pulled from the subterranean location after the milling is completed. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined by the appended claims.
A bottom hole assembly comprises a milling tool and associated drive motor with a shifting tool that is capable on deployment to selectively grab, shift and release from sliding sleeves when the bottom hole assembly is removed from the subterranean location. The shifting tool is preferably protected from the returning flow of cuttings to avoid erosion or clogging from the cuttings being circulated to the surface. The shifter tool can be of a known design to enable the milling of ball seats or entire plugs in the same trip as the operation of the sliding sleeve valves associated with the treatment operation so that the well can then be in position to commence production or injection once a suitable string and service packer are set in position. Typically the sleeves are open for the treatment and then closed after milling as the bottom hole assembly is removed.
Referring to
The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, emulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.
The milling assembly 12 advances in
It is preferred to locate the shifter 14 above the milling assembly 12 but the opposite orientation is also contemplated but is less preferred. What is shown is a one trip method where the barriers such as seats or isolation plugs can be milled out in a single trip going into the hole and some or all the sleeves or other types of tubular valves closed on the trip out of the hole with the milling assembly. It should be noted that the shifter 14 can be configured to engage all the sliding sleeves or less than all the sliding sleeves as required. One or more than one shifting tool can be used where one serves as a backup for another or where one is configured to operate different sliding sleeves or valves in the borehole.
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:
