PREDETERMINED FRACTURING ACCESS VALVES

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Application No. 14/875269, filed on October 5, 2015, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The field of the invention is hydraulic fracturing and more particularly smart object that can be preconfigured to operate a predetermined valve in an array of valves to fracture in any desired order.

BACKGROUND OF THE INVENTION

[0003] Fracturing can be accomplished using a series of valves that each have ball seats. The ball seats get progressively larger going uphole and progressively larger balls are launched or dropped to sequentially open the fracturing valves in a bottom up direction. As one zone is fractured the next ball isolates the already fractured zone and opens the next valve going in an uphole direction. The problem with this system is there is a limit to how many balls of different sizes can be accommodated in a borehole of a given size. Another problem is that the balls have such small size difference to accommodate as many zones as possible that surface personnel can inadvertently grab the wrong ball. Organizers for such ball arrays are shown in US 8157090. Despite the use of organizers to keep track the wrong ball can still be inadvertently picked.

[0004] One offered solution to the progressively larger ball seats in a bottom up fracturing operation has been offered in US 7322417. Here the same ball is used and all but the initial ball seat are retracted. Once the first ball lands and opens a fracturing valve, it also extends the next ball seat up to accept the same size ball. Here the offered advantage is that all the balls are the same size. The limitations are that the actuation order is still fixed from bottom up and the mechanism that connects the shifting of one ball seat to the extension of a ball seat above can be quite complex and expensive to build or operate.

[0005] Also relevant are US7552779 and US7325617; US 4,823,882; US7, 377,321; US 8,356,670; US 8,701,776; US 9,004, 180; US 9,004, 179; US 8,616,285; US8,863,853; US8479823; US8668013; US8789600; US8261761; US8291988; US8397823; US8646531 and US8770299). [0006] The present invention seeks to optimize a fracturing operation by using intelligent objects such as balls or darts that keep track of how many valve assemblies have been passed by the object so that the mechanism of the object can be reconfigured at the desired valve for latching and ultimately shifting the valve with applied pressure in the borehole. 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 can be determined from the appended claims.

SUMMARY OF THE INVENTION

[0007] An intelligent dart or ball or other shape is dropped or pumped into a borehole that has multiple valves for access to the formation through which fractures are initiated. The intelligent object engages with the valves as it passes with retractable engagement dogs that are outwardly biased but not to the degree needed to find support unless the valve in question is the one that needs to be operated. In that event the dogs become supported and pressure is applied to the object to shift the valve to the open position. The object can be released at a later time remotely or can be collected or "fished" or can be milled out. Subsequent objects can be landed in the same sleeve after the initial object is released to close it or to close the open port by moving a second sleeve against a first sleeve. Fracturing in any order is envisioned.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a section view of a sleeve that can be engaged by the intelligent object;

[0009] FIG. 2 is the view of FIG. 1 with the object about to land on the sleeve;

[0010] FIG. 3 is one embodiment of the object;

[0011] FIG. 4 is an alternative embodiment of the object;

[0012] FIG. 5 is an end view of the object in FIG. 4

[0013] FIG. 6 is another alternative embodiment of the invention;

[0014] FIG. 7 is a detailed section view of one embodiment of the object;

[0015] FIG. 8 is a rotated section view from FIG. 7;

[0016] FIG. 9 is a section view in the direction of arrow 9 in FIG. 7

[0017] FIG. 10 is an alternative object design whose locking feature is electronic. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] FIG. 1 shows one of several variations for the fracturing sleeve valve 10 that can open the ports 12 in housing 14. A seat 16 engages dogs 18 that are biased out radially by springs 20. Dogs 18 are connected by a schematically illustrated link 22 best seen in FIG. 9. Link 22 can be connected to a rotating circular ratchet 24 that turns in a single direction each time the dogs 18 get pushed against springs 20. Ratchet 24 rotates on shaft 26 and the amount of rotation is sensed by the processor 28. The processor 28 is programmed to sense a predetermined amount of rotation at which time it can extend a schematically illustrated lock pin or pins 30 into the ratchet 24 so that the dogs cannot retract. Once the dogs 18 land on the next seat 16 they will support the object 32 onto the seat 16 so that pressure against seal assembly 34 moves sleeve 36 to open ports 12. The locking of the dogs 18 in the extended position can occur after a predetermined number of cycles of retraction and extension measured by a processor 40 that can then move a support under the dogs 18 to prevent their retraction as illustrated in FIG. 10. This form of locking can be triggered electromagnetically, electromechanically or with a pressure switch to name a few examples. The seal assembly 34 can be adjacent packer cups 42 and 44 or they can be spaced further apart in an alternating pattern with rows of dogs 46, 48 and 50 as shown in FIG. 4.

[0019] The preferred order of operation of sleeves 36 is bottom up so that each landed object that shifts a given sleeve can isolate zones below that have already been fractured. However other orders of sleeve operation are possible. For example, if the sleeves 36 had two landing locations that straddled the ports 12 than the initial object could shift sleeve 36 a first time and another object 32 can land on another seat that would be above the now open ports 12 so that pressure could again be built up to move the same sleeve a second time and blank off ports 12. In this case the sleeve 36 would be configured with wall ports that align with ports 12 in the open position and a blank section that comes into alignment with the ports 12 for the closed position. Another way to be able to open the ports 12 and then close them would be to use two adjacent sleeves. The first sleeve can be as shown in FIG. 1 and the second sleeve can be identical to it and simply push the first sleeve enough to place the second sleeve that is adjacent in line with the ports 12 to close them.

[0020] Another feature can be a remote release for the object 32 using the processor 28 or 40 so that after shifting a sleeve such as 36 the object 32 is released to go the hole bottom or a catcher that is not shown. Alternatively the various landed objects 32 on the various sleeves 36 can be simply milled out or flowed out of the well when production starts after a bottom up sequence for fracturing. [0021] The objects 32 can all be identical and just be programmed to engage specific seats in specific sleeves in a predetermined order. They can have external indication of how many cycles they will undertake before locking the dogs so that the next sleeve is landed on. The ratchet mechanism can be linear or circular. Any locking feature that can be actuated after a predetermined moving of the dogs in and out can be employed. In this manner the landing location for each object is predetermined. The exterior shape of the object can vary from spherical to an elongated shape. The internal components such as the processor 28 can be cushioned with springs such as 60 or 62. Those skilled in the art will appreciate that the present invention involves programmable objects to land on predetermined sleeves to facilitate bottom up fracturing. With some modification to the sleeve design or by using sleeve pairs the ports to the formation that are opened can also thereafter be closed. This feature can allow re-fracturing only specific zones by closing the remaining sleeves. The objects can be remotely triggered to release from a shifted sleeve. Optionally the sleeves can communicate data on their movement or lack thereof in real time to a surface location using a variety of signaling techniques to the surface such as acoustic, mud pulses, RFID or other types of known telemetry techniques. Of course a pressure buildup at the surface is another signal that an object has landed on a sleeve.

[0022] Another alternative can be electronic, or proximity or over the air or fluid signaling from each sleeve as the object goes by it. After the predetermined number of signals are detected then the dogs can be extended to land on the very next sleeve for operating the sleeve with applied pressure. In that manner the dogs do not need to physically engage a profile on each sleeve as that sleeve is passed. Release of the objects after landing can be accomplished with pressure application and removal cycles that eventually allow the support for the dogs to be undermined so that pressure in the borehole can displace the object from the supported location.

[0023] 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. Another operation can be production from said zone or injection into said zone.

[0024] 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: