Patent Application
20190040715
The field of the invention is multistage treatment systems and more particularly where the lower completion is run in with a work string and power is supplied to valves from a remote location along the work string to valves and associated packer(s) for isolation.
Stage treatment systems have used sliding sleeve valves that are sequentially operated to open with balls of progressively larger diameters landed sequentially in a bottom up direction for stage treatment of an interval. For large intervals a large number of balls that vary little in size are needed. At the end of the treatment the seats and balls can be milled up for production leaving the sliding sleeves in which the seats were supported behind. In some cases the balls could be made of a disintegrating material as well as the seats to avoid a milling trip in the hole.
Other ways of actuating sliding sleeves have been proposed. Some of them involved stored electric power at each sliding sleeve that is triggered remotely such as with a field generated from an object dropped into the borehole. Other devices relied on hydrostatic pressure on one side of a piston referenced on an opposed side to a low pressure chamber and a trigger mechanism to enable piston movement taking advantage of the pressure differential on the piston to move a sliding sleeve once. Some designs duplicated the opposed chamber design on one or more pistons so that a given sliding sleeve could be shifted in opposed directions at least once. These systems were rather bulky and complex and in some installations there was insufficient physical space to deploy the needed components to get multiple movements.
To date a practical solution for electrically powered sliding sleeves with electric power coming from a surface or wellhead location has not been proposed. The present invention addresses such a system where a work string supports a lower completion and power comes down the work string to an array of electrically powered sliding sleeve valves alternating with packers. The sleeves can be directly or indirectly electric powered. Direct powering is by using an electric motor and indirect powering is by running a hydraulic pump with the supplied electric power and actually moving the sliding sleeve with developed hydraulic pressure.
An electric cable runs the length of the work string to a separable connection such as an inductive coupler or a wet connect. The electric cable continues past a production packer that stays in the hole and continues to each of the sliding sleeves that stay in the hole with the lower completion. Treatment in any sequence is possible as well as rapid change from one interval to another in the event of an incipient “screen out” where the formation stops taking solids such as a proppant during a fracturing job. A dump zone valve is provided near hole bottom to redirect slurries in the event of a screenout to prevent clogging the borehole. After all the intervals that need treatment are treated the work string releases from the lower completion above the set production packer at the inductive coupling or the wet connect. The work string is removed and a production string with the upper portion of the inductive coupling or the wet connect is run back in. The production string can have accessory conduits such as chemical injection lines, control lines and an upper portion of the electric cable that was also on the work string. The lower assembly can have sensors in isolated intervals by the packers on the work string to send well data to the surface through the inductive coupler or wet connect. The same data transmission capability is retained when the production string replaces the work string. These and other features 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 by the scope of the appended claims.
Relevant to the present invention are U.S. Pat. No. 9,404,340; WO2016126261 and EP 2636844.
A lower completion for open or cased hole is delivered on a work string. Electric power extends from a remote location past a production packer and to an array of electrically operated sleeves alternating with packers. An inductive coupling or wet connect allows the work string to release from the production packer and a production string tagged into the production packer for continued operation of the sliding sleeves. In the event of an incipient screenout a different sliding sleeve can be opened quickly or a sliding sleeve near hole bottom can be opened to maintain flow. The sliding sleeves can be directly or indirectly operated with electric power from a surface or wellhead location. A wet connect or inductive coupler allows removal of the work string and replacement with a production string for continuing functionality of the sliding sleeves.
There are several noteworthy features. The system delivers a lower completion on a work string where power is delivered from a remote location such as a surface or a platform and the work string is removable in favor of a production string that reconnects electric power to the sleeves 16 or the dump zone sleeve 32. Having multiple sleeve that can be quickly opened when treating one zone is an advantage if there is a developing screenout. In that event, another sleeve 16 can be opened to keep the flow moving or, preferably, the dump zone sleeve 26 can be opened to keep the treatment slurry moving to a location of less or no interest in the borehole to avoid totally plugging the lower completion in the event of a screenout. This is preferred to opening another sleeve 16 as a screenout looks imminent because neither the zone being treated at the time nor a different zone where another sleeve 16 is opened will get properly fractured or treated. Sleeves 16 or 32 can be directly powered electrically such as by operating an electric motor or they can be indirectly powered by electricity such as by operating a hydraulic pump and using hydraulic pressure to shift the sleeve. With the power provided remotely, each valve can be simply operated open and closed multiple times with a pair of electric motors or one that can be reversed or hydraulic valving to direct pressure to above or below a piston to get the sleeve moving in one of two opposed directions. There is no milling out needed and production can begin right after the treatment ends and the work string removed and replaced with the production string. To the extent it may be cost effective to save a trip in the hole to replace the work string with the production string, the production string can be run in initially without safety valves which can then be inserted after the treatment. The sleeves 16 can have two movements to open a clear port for treatment and then to be moved again to open a screened port for production. Alternatively two sleeves can be used with a first opening an unobstructed port and the second opening a screened port as the first sleeve is closed over the treatment port. After the treatment ends a tree is installed with the production string 56. The valves 16 and 32 are schematically illustrated to include an electric motor driver for direct operation or to include an electric driven hydraulic pump and valving to opposed sides of an actuating piston for the valves so that the valves can be moved in opposed directions multiple times in a bottom up or top down or random order.
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, demulsifiers, 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 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:
