Patent Application
20180223626
The field of the invention is borehole tools operated between multiple positions with interventionless signaling to pressurized fluid sources associated with the borehole tool or a surrounding annulus in the borehole.
Sliding sleeves in tubular strings have been moved in the past with direct application of hydraulic pressure applied to a sealed chamber where the sleeve acts as a piston. Rising pressure puts a force on the sleeve to change its position. This is a sleeve actuation method frequently used in subsurface safety valves such as in U.S. Pat. No. 4,473,122. Other ways of moving a sleeve are to use ball screws or similar mechanical devices to force a sleeve to translate or to rotate as shown in WO97/30269.
Sleeve valves are frequently used in fracturing where ports are covered by a sleeve when running in and subsequently opened for treatment. After treatment the ports are closed with sleeve movement and then need to be reopened when the entire zone is treated for production from the formation. One way this is done now is to shift a sleeve with pressure on a ball landed on a seat supported by the sliding sleeve so that the ports are opened for treatment. After the treatment through an opened valve is concluded another ball that is larger lands on the next sleeve uphole and in effect isolates the ports opened by the previous sleeve so that treatment at the next set of ports in an uphole direction can take place. This process is repeated with progressively larger balls until the entire interval is treated. After that, all the balls are drilled out and if needed certain sleeves are closed with a shifting tool before production begins through the open sleeves. There are drawbacks to this well-known method of fracturing or otherwise treating a formation. There can be a large number of balls that have to be delivered in size order that are only minimally different in diameter. This can cause operator confusion. The sleeves have seats that restrict the produced fluid flow to some degree. The milling is time consuming and creates debris in the borehole that can adversely affect the operation of other tools with small clearances.
Sliding sleeves can be individually moved with one or more control lines to each sleeve but using this technique in situations with many sleeves is expensive and time consuming. Another way is to send power to operators for sleeves through a wired system. This technique is also expensive and time consuming. Valve members have been designed to be pressure responsive to pressure cycling using unequal piston areas and a j-slot mechanism to operate a single sleeve. However, this design is not useful with arrays of valve members that need to be distinctly addressable to move in a predetermined sequence.
The method and apparatus of the present invention provides an interventionless way to open, then close and then reopen specific sliding sleeves so that a particular sleeve can provide access for treatment and then get closed as another sleeve is actuated to continue the treatment. Thereafter a selected sleeve can be reopened and optionally locked open for production. Ball seats and milling are eliminated allowing for production to begin that much faster. The movement of the sleeve is accomplished with signal responsive valves that direct tubing hydrostatic pressure to different piston areas on opposed sides of a piston to make the piston move in the direction desired. Tubing or annulus pressure can be employed if the annulus is not cemented. An option is available for intervention in the tubing such as with a straddle tool that can preferably equalize the piston areas on opposed sides of the piston and allow piston movement with pressure applied through the straddle packer tool. These and other aspects of the present invention will be more readily apparent 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 appended claims.
An array of sliding sleeve valves are uniquely addressable without control lines or wires to open for a treatment and then close and then selectively open for production. The discrete movements employ an available pressure source such as tubing pressure and change the piston areas on opposed sides of a sliding sleeve valve to get the desired movements. Access valves to tubing pressure can be actuated in a desired sequence with signals such as acoustic or electromagnetic, for example. Access to one piston area that communicates opposed and offsetting piston areas to the tubing hydrostatic can be achieved with a straddle tool breaking a rupture disc. The piston is then in pressure balanced and can be moved in a desired direction with the straddle tool straddling access locations to the piston from above or below.
Referring to
Specifically, there is a sliding sleeve 12 that slides over a mandrel 18 and has an outer seal 14 against an outer housing 20 and an inner seal 16 against the mandrel 18. The seals 14 or 16 can be a single seal or multiple seals. Outer housing 20 has a port 22 and sliding sleeve 12 has a port 24 that in
There are four chambers that can be selectively communicated to tubing hydrostatic pressure in passage 30. There is no need to add to tubing hydrostatic pressure. Alternatively, if the annulus is open to pressure annulus hydrostatic can be used. If the annulus is cemented then tubing hydrostatic in passage 30 is used. To get the capability to open, close and reopen without intervention in passage 30 there are three chambers needed. To operate a given valve 10 with intervention on top of being able to open, close and reopen the valve 10 a fourth chamber is used. Chambers 32 and 34 communicate to the uphole side of the sliding sleeve 12 and chambers 36 and 38 communicate to the downhole side of the sliding sleeve 12. Remotely actuated valves 40, 42 and 44 respectively communicate hydrostatic pressure in passage 30 to chambers 32, 36 and 34. As stated before these valves 40, 42 and 44 respond to unique signals that can be acoustic or electromagnetic or coded pressure pulses to name a few options to operate in a predetermined sequence for moving sliding sleeve 12 between open and closed positions. Another power source can be electric power. It would rely on use of a toroidal current sensor attached to the electronic valves such as 40, 42 and 44 and an electrical gap on the OD of the toroid. The wound wire in the toroid (like a transformer coil) is excited by current along the surface of the casing (but that current must pass through the toroid and not leak to the OD outside it). Access to chamber 38 is through rupture disc 46 as will be explained with regard to
All the chambers 40, 42, 44 and 38 start at low or nearly atmospheric pressures. There is no need to pressurize these chambers before running in and cementing if that is to be done. To move from the
To close valve 10 after it is opened, valve 42 is signaled open to allow hydrostatic in passage 30 to access chamber 36 to increase its volume as hydrostatic pressure is applied to piston area 52 which is greater than piston area 50 so that a net force to sliding sleeve is applied to reverse the
Those skilled in the art will appreciate the various advantages of the device described above. First there can be an array of valves in a zone of interest that can be sequentially addressed without intervention and without the need to run control lines or wires to each valve that communicates hydrostatic tubing pressure to variable volume chambers in a sequential manner to obtain at least three movements of a sliding sleeve. In the preferred embodiment three chambers allow three sleeve movements in opposing direction to open a closed valve for treatment and then close it after treatment and then open it for production, for example. Using a chamber and a remotely actuated valve associated with the chambers there can be as many sliding sleeve movements as there are valves and associated chambers. In another feature of the above described device, there is a chamber that can be accesses with intervention that has the benefits of equalizing opposed piston areas to make the sliding sleeve easier to move with less applied pressure to essentially overcome seal friction. The other and further advantage is that the straddle tool that breaks a rupture disc or the like to gain access to the chamber to equalize opposing piston areas can also be used to add pressure below or above the sliding sleeve in its pressure balanced configuration to either close or open the valve assuming at least one of the valves or the rupture disc to passage 30 have opened. The various chambers on one side of the sliding sleeve can be circumferentially offset to allow room for more chambers and associated tubing hydrostatic access valves. At some point a tradeoff occurs between how many chambers and associated valves are put on either side of the sliding sleeve when the point is reached that the drift dimension of passage 30 needs reduction to accommodate more chambers while retaining the needed pressure rating of the assembly. The sliding sleeve is in pressure balance from the two chambers on each side before any passage valves open because all the chambers are at or near atmospheric pressure and the piston areas on opposite sides offset each other. Alternatively, the chambers can be at the available hydrostatic and the system will operate to the extent pressure can be applied to the passage in the housing to have available a pressure difference when the remotely actuated valves open. This can occur if during running in there is a condition where there is flow past a seal. Normally the chambers would be closed with seals at the surface rather than being pressurized before running in to the expected hydrostatic pressure.
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:
