System to be used in well shaft having multiple zones (versions), and development method of described well shaft

VALVE ASSEMBLY, VALVE ASSEMBLY ACTIVATED IN REACTION TO FLUIDS, AND METHOD FOR TRIGGERING THE ACTUATION OF AN ACTUATOR MEMBER IN REACTION TO A FIRST TYPE OF FLUID

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to systems and methods for selectively controlling the flow of fluids within a production column in a well. In particular, the invention relates to devices and methods for actuating flow control valves in response to high amounts of water or gas in production fluids obtained from specific production zones within a well.

2. Background of the Invention

Wells may pass through several hydrocarbon-bearing reservoirs, or they may extend over a long distance through a single reservoir. One technique for increasing well production is to drill the well in a number of distinct zones, either in the same hydrocarbon-bearing reservoir or in different hydrocarbon-bearing reservoirs. During the later stages of hydrocarbon production from an underground production zone, water or gas often enters the production fluid, making production less profitable as the production fluid becomes increasingly diluted. For this reason, when there are multiple production zones along a well, it is desirable to shut off the inflow from those zones that are experiencing significant water and/or gas influx. It is therefore important to have a means of controlling fluid ingress at a given location along a production column.

Many different forms of valve arrangements are known for controlling the flow of liquid through an opening or passage. These arrangements include the use of liquid-expandable materials that expand in contact with a liquid to obstruct a passage or opening, and that shrink, when not in contact with a liquid, to permit flow through the passage or opening. See United States publications US2007/0034255 and US 2007/0034817.

The structure and operation of intake control devices are well known. Intake control devices do not yet have an acceptable means to selectively shut off the flow into the production column in the event of water and/or gas invading the production layer. For actuation, most intake control devices require the enabling of instrumentation located in the well, or an intervention in the well. It would be desirable to have a mechanism to selectively close the intake control device.

The present invention solves the problems of the prior art.

SUMMARY OF THE INVENTION

According to embodiments, a system and method for controlling fluid ingress into a production string is disclosed, utilizing various flow control devices to control fluid flow into respective zones of the wellbore. According to some embodiments of the invention, a fluid seal comprises: an expandable material capable of assuming an expanded state and an unexpanded state; and in which the expandable material is positioned such that the expandable material restricts the flow of fluids when the material comes into contact with a first type of fluid.

According to another embodiment of the invention, a fluid-driven apparatus comprises: an expandable material capable of assuming an expanded state and an unexpanded state; an actuating member and wherein the expandable material is positioned such that the expandable material actuates the actuating member when the material comes into contact with undesirable fluids.

According to another embodiment of the invention, a method of triggering actuation of an actuator member in reaction to fluids comprises: fluids causing an expandable material to move from an unexpanded state to an expanded state; and wherein the expandable material is positioned relative to the actuator member such that the expandable material actuates the actuator member when the material comes into contact with undesirable fluids.

An advantage of this invention is that it can be used to automate and control the detection of excess and undesirable fluid production from multiple zones in a single well. These flow control devices can shut off further production of undesirable fluids and transmit signals upwell to alert the operator of these interruptions. The production of each zone can be individually controlled and adapted to its specific local conditions to optimize the total productivity of the well.

Other features and advantages of the invention will become more readily apparent from the following detailed description, when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in detail below, with reference to the plurality of drawings, by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent like parts in the various views of the drawings, and in which:

FIG. 1 is a cross-sectional side view of an exemplary multizone well and production assembly incorporating an intake control system in accordance with the present invention;

FIG. 2 is a side, cross-sectional view of an exemplary multizonal well and production assembly depicting the zonal migration of undesirable fluids;

FIG. 3 is a cross-sectional side view of an exemplary multizone well and production assembly depicting the zonal migration of undesirable fluids into the inlet control devices;

FIG. 4 illustrates an intake controller device depicting an open operating state, in accordance with one embodiment of the invention;

FIG. 5 illustrates an intake controller device depicting a closed operating state in accordance with one embodiment of the invention;

FIG. 6 illustrates an intake controller device depicting an open operating state, in accordance with one embodiment of the invention;

FIG. 7 illustrates an intake controller device depicting a closed operating state in accordance with one embodiment of the invention;

FIG. 8 illustrates an intake controller device depicting an open operating state in accordance with one embodiment of the invention;

FIG. 9 illustrates an intake controller device depicting a closed operating state in accordance with one embodiment of the invention;

FIG. 10 illustrates an intake controller device depicting an open operating state, in accordance with one embodiment of the invention;

FIG. 11 illustrates an intake controller device depicting a closed operating state, in accordance with one embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details presented herein are by way of example and for purposes of illustrative discussion of embodiments of the present invention and are presented only to provide what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this connection, no attempt is made to show the structural details of the present invention in more detail than is necessary for a fundamental understanding of the present invention, the description taken in conjunction with the drawings making it apparent to those skilled in the art how the various forms of the present invention may be embodied in practice. Furthermore, similar reference numerals and designations in the various drawings indicate similar elements.

The present invention generally relates to a system and method for controlling the ingress of fluids into a production column, using various flow control devices to control the flow of fluids into respective zones of the well.

Referring generally to FIG. 1, one embodiment of a well system is illustrated, such as utilizing various flow control devices. In this embodiment, a well system 101 comprises production string 103 installed in a well 102. Although well 102 is shown in FIG. 1 as being a vertical well, well 102 may be a lateral or horizontal well, according to other embodiments of the system. Well 102 is drilled into a subsurface formation 104 that may contain production fluids such as petroleum. In the illustrated example, well 102 is cased with casing 109. Well 102 may also be an open hole, in accordance with other embodiments of the system. Zones 106 and 107 are isolated from each other, above and below, by packers 108 in well 102 between zones, around production string 103, which is used to access the various zones 106 and 107. Within each zone there are admission control devices number 110, 115 and 116. These intake control devices consist of a well screen 111, 117 and 120 which controls the entry of solid particles into the well 102, the well screen 111, 117 and 120 comprising conduits 114, 120 and 123 for transporting the hydrocarbon fluid, the conduits 114, 120 and 123 being provided with a filter (not shown in the drawing) to reduce the entry of solid particles into the conduits 114, 120 and 123. In the illustrated embodiment, the inlet control devices 110, 115, and 116 include primary flow control devices, 112, 118, and 121, such as a valve capable of being actuated and providing a flow path for transporting hydrocarbons through openings 113, 119, and 122 into the production string 103, to be transported upwell 114 to the surface.

Referring generally to Fig. 2, as well production continues, zonal migration of undesirable fluids, a phenomenon known as water crowning, begins to occur. This interzonal migration must be controlled. Referring to Fig. 2, the zonal migration of water has flooded zone 2 107, while part of zone 1 106 near the intake control device 110 has experienced some water migration. Zonal migration of undesirable fluids, e.g. water 201, will move into production column 103. Current techniques for detecting these undesirable fluids occur upwell, but it will be impossible to distinguish whether the undesirable fluid is being transmitted from inlet control device 110, 115 or 116. If it is determined that a reduction of undesirable fluids is necessary, production logging tools will be used to detect from which inlet control devices 110, 115, and 116 the undesirable fluids are introduced into the production string. To determine what fluid is entering the production string through the inlet control devices 110 and 115, intervention services (piano wire, flexible tubing, etc.) may be used to close valves 112 and 118 of the inlet control devices 110 and 115. These operations are costly to well operators, interrupt well production, and pose potential risks of damage to well completions. For this reason, many wells are left untreated, and this leads to inferior quality production from the wells. Embodiments of the present invention are intended to correct the deficiencies of the prior art with respect to intake control devices. Embodiments of the present invention automate the procedures described in Figs. 1 and 2 using expandable materials.

With general reference to Fig. 3, when interzonal migration of undesirable fluids occurs, for example water, and water production at openings 306 and 310 increases, water entering from zones 106 and 107 will come into contact with the expandable material in valve 311 and 307. The expandable material changes state from an unexpanded state to an expanded state when in contact with the water to close valves 307 and 311. This closing of the valves closes the flow path between screen 312 and opening 310, and screen 308 and opening 306. The inlet control devices of the present invention detect undesirable fluids and close the valves that are producing undesirable fluids, e.g., water, without any intervention. Opening 302 continues production into the production string 103 and upwell 114 without any interruptions. The closure of intake control devices 305 and 309 has no impact on the production capacity of intake control device 301, and production of desirable hydrocarbons continues.

Fig. 4 shows an embodiment of the present invention. Fig. 4 presents a cross-sectional view of the inlet control device 410. Formation fluids flow through the wellbore screen 402 into the valve assembly 406. The valve assembly includes a passage 407 and the expandable material 408. This expandable material 408 may be composed of polymers or composites. The expandable material 408 is arranged in a continuous band wrapped around a metal mandrel 409, which is used to confine the polymer and guide the expansion of the expandable material in a radial direction. Formation fluid flows through passage 407 and through opening 405 into production string 404. The expandable material 408 is formulated so that it is capable of assuming an expanded state and an unexpanded state when the polymeric material is exposed to certain fluids. The expandable material 408 is formulated so that its configuration changes when exposed to certain fluids.

The intake control device 410 functions to detect the presence of undesirable fluids in the formation fluids 403. The expandable material 408 is formulated so that it expands only when predetermined levels of undesirable fluids, such as water, exist, but if the production fluids contain primarily hydrocarbons, the expandable material 408 remains in an unexpanded state.

Thus, the embodiment of Fig. 4 depicts the production fluid containing primarily hydrocarbons and the expandable material will remain in an unexpanded state. The valve assembly remains open and the formation fluid can flow through passage 407 into the production string 404 through opening 405.

Fig. 5 illustrates an embodiment of the present invention where the intake control device is now closed. When production fluid 403 flows into screen 402, expandable material 408 will detect the presence of undesirable fluids and will absorb such fluids, and the expandable material will change its state to an expanded state. The location of the expandable material 408 allows its volume to expand radially outward and the expandable material 408 expands until it blocks and seals the passage 407. The well 402 may or may not include a casing. In Figures 4 and 5, the well 402 does not include a casing. In both cases, the expandable material 408 expands to adequately seal against the well or casing. The location of the metal mandrel 409 ensures that the expandable material expands its volume radially outward to seal the passage. Once this expansion occurs, the passage 407 is blocked by the expandable material 408 and the valve assembly 406 is closed. The formation fluid 403 is therefore prevented from entering the opening 405 and flowing into the production string 404. In this embodiment, valve assembly 406 automatically detects undesirable fluids when such fluids reach a certain level. Once valve assembly 406 detects a certain level of undesirable fluids, the valve closes as expandable material 408 absorbs water and expands radially outward blocking passage 407. In this embodiment, the expandable material 408 both functions as a detector of the fluids within the formation fluids 403 and as a sealing element 501 by expanding radially and blocking the passage 407 that closes the intake control device.

The present embodiment encompasses expandable materials 408 that expand when the amount of formation fluid increases to a certain level of undesirable fluids. If the undesirable fluid content of the formation fluid decreases, the expandable material can revert from an expanded state to an unexpanded state.

Once the expandable material returns to an unexpanded state, valve assembly 406 of intake control device 410 will open and hydrocarbon production fluid will flow into production column 404.

The present embodiment further encompasses expandable materials 408 that expand and close passage 407 to stop the undesirable production flow. In this case, valve assembly 406 is permanently closed, or the valve can only be reopened through appropriate intervention. The present embodiment further encompasses expandable material 408 that expands when the undesirable fluid content of the formation fluid increases. If the composition of the formation fluid changes and the composition of undesirable fluids falls below a predefined limit, the expandable material will remain expanded, but contraction can be initiated and accelerated by using external triggers. Triggers can be other fluids (which are pumped or released from a fluid reservoir located at the completion facility), electric, magnetic or electromagnetic fields.

Fig. 6 illustrates a further embodiment of the present invention. Formation fluid 601 flows through screen 602 and into a housing consisting of channels or annular spaces 603 and 607. Channel 603 connects to expandable material 604 so that expandable material 604 is always exposed to the formation fluid. The expandable material 604 is confined between the channel 603 and the piston 606, so that the expandable material 604 expands its volume unidirectionally, in the case of our Figure 6, to the left. The formation fluid enters the housing through the channels 603 and 607. The piston 606 connects to the valve 608 through a connecting rod 605. If the formation fluid 601 has not reached a predetermined level of undesirable fluid, as shown in Figure 6, the expandable material will not expand, and the valve 608 remains open and therefore the opening 609 is open and not blocked, and the formation fluid 601 can flow from channel 603, through channel 607, through opening 609, into the production string, to be transported to the surface.

Ά Fig. 7 illustrates the same embodiment as in Fig. 6, with the intake control device closed. Formation fluid 601 flows through screen 602 and into channel 603. Channel 603 connects to expandable material 604, and when expandable material 604 detects undesirable formation fluids, expandable material 604 will absorb the undesirable fluids and expand. Expandable material 604 is confined between channel 603 and piston 606. Once the expandable material 604 senses the undesirable fluids, it swells and expands its volume unidirectionally. This expansion or swelling of the material pushes the piston 606, which is connected to the connecting rod 605, to the left in our embodiment, as illustrated in Figure 7, which in turn pushes the valve 608, which finally blocks and seals the opening 609 and thus closes the intake control device. When this occurs, valve 608 is closed and formation fluid 601 cannot flow into the production string through channel 607 and opening 609. Expandable material 604 senses the predetermined undesirable fluid amount and automatically expands, thereby pushing the piston to the left, which in turn closes valve 608. No intervention ever occurs to close valve 608. The expandable material 604 functions, in this embodiment, simultaneously as a detector of undesirable fluids and as an actuator providing force to move the piston 606 and the connecting rod 605, to actuate the valve 608. Likewise, if the expandable material 604 detects desirable fluids, the material may change to an unexpanded phase, thereby reducing the force on the piston 606 and connecting rod 605, which in turn will actuate the valve 608 and cause the valve to reopen, allowing production fluid to flow upwell 610.

Fig. 8 illustrates a further embodiment of the present invention. One problem that may arise with the expandable material is that the force that the expandable material generates to actuate and displace the piston and therefore move the valve may not be very large. The embodiment of Fig. 8 addresses this problem. In Fig. 8, the expandable material is confined in a small volume. The problem with expandable material is that the force that the expandable material generates when in an expanded state is usually not very large. In Fig. 8, the force generated by the expandable material in an expanded state moves a first piston. The movement of the first piston will initiate the release of pre-charged fluid from a chamber. The released pre-charged fluid will initiate a much larger force to move a second piston. The movement of the second piston will actuate the valve. The embodiment of Figure 8 is a form of force multiplication. The expandable material 703 in the present embodiment serves as a detector of undesirable fluids and as a triggering device, which controls the actuation of a much larger force to actuate valve 713. Formation fluids enter screen 701 and into both channels 702 and 712. 0 expandable material 703 is connected to channel 702, and expandable material 703 is confined between channel 702 and piston 706, so that expandable material 703 expands its volume unidirectionally to the left in our embodiment in Fig. 8. Expandable material 703 will not swell in the presence of desirable fluids and therefore will not move piston 706. Piston 706 is connected to a connecting rod 704, which has a bore 705. Production fluids will flow through the screen and into channels 702 and 712 and uphole 716 through opening 714. Valve 713 remains open when expandable material 703 is in an unexpanded state when the formation fluid contains desirable fluids. When the fluid has not reached a predetermined undesirable level, as shown in FIG. 8, expandable material 703 will not expand, and orifice 705 will not align with channel 707 and channel 711. In this case, chamber 708, which may contain high pressure gas (e.g., nitrogen), will not release the pre-charged fluid into channel 711. Channel 711 is connected to a piston 710, which connects to a connecting rod 709. Piston 711 is connected to valve 713 through connecting rod 709. When expandable material 703 is not expanded, valve 713 is open. Valve 713 remains open since there is no pre-charged gas released from chamber 708 that would cause piston 710 to move to the left in our embodiment of Fig. 8 and close valve 713. Fluid can flow 712 through opening 714 and upwell 716 into the production string.

Fig. 9 illustrates the embodiment of Fig. 8 in a closed position. When the fluids flowing into the channel 702 contain undesirable fluids, the expandable material 703 will swell and expand. The expandable material 703 is confined between the channel 702 and the piston 706. As it swells, it will expand its volume and push against the piston 706 and the connecting rod 704. The movement of the connecting rod 704 will cause the orifice 705 to eventually align with the channels 707 and the channel 711. When port 705 aligns with the two channels, this will allow pre-charged fluid to be released from chamber 708, through channel 707, port 705, and channel 711, into piston chamber 715. The pre-charged fluid within piston chamber 715 will push piston 710 and connecting rod 709, which in turn pushes valve 713 to finally close port 714. Once valve 713 is closed, formation fluid cannot flow into the production string. The expandable material of the present embodiment automatically senses the predetermined undesirable fluid content. When this occurs, the expandable material triggers the release of pre-charged fluid from the chamber into the piston chamber and this in turn closes the valve. No intervention is required to automatically open or close these valves.

Figs. 10 and 11 illustrate an additional embodiment of the present invention utilizing many of the features of the embodiments as illustrated in FIGS. 8 and 9. The embodiment may have an additional chamber comprised of indicator elements unique to each intake control device. Valve 713, when in the closed position, will cause an additional connecting rod 1002 to move. This connecting rod 1002 contains an orifice 1003, and when the connecting rod 1002 moves, the orifice 1003 becomes aligned with the channel 1001. The indicator chamber 1004 is then opened and releases the indicators, which may be, among others, chemicals, solid particles or granules. These indicators are released into the production column through the orifice 1003 and the channel 1001. The operator on the surface can detect indicators in the production stream and, through these indicators, can determine which intake control devices are closed. If there are multiple intake control devices, as illustrated in our embodiments, each intake control device may contain a unique indicator, so that the operator can determine which intake control devices have been closed. These indicators can be liquid, solid or gaseous, and are identifiable upwell due to their different signatures. For example, such indicators can be the microbarcodes of rare-earth doped glass, as described in Microbarcodes of Rare-Earth Doped Glass, Dejnek et al., Vol. 100, No. 2, Pages 389-393, January 21, 2003.

In a further embodiment of the present invention, the indicators may be incorporated into the expandable material in the valves of the intake control device or into expandable capsules, which are exposed to the production fluid. At a certain level of composition of the undesirable production fluid, the capsules will swell and release the indicator. The indicators may be arranged so that they are unique to each zone of the production column and thus, once released, notify the operator of impending increases in certain zones of undesirable fluids. The operator may then take appropriate action either through intervention or through the modalities as described in the present invention.

Embodiments of the present invention may also utilize tube waves to send signals upwell. The indicator chamber 1004 of Fig. 10 may be replaced by a vacuum, or atmospheric, chamber.

Whereas many changes and modifications of the present invention will undoubtedly become apparent to one of ordinary skill in the art after reading the above description, it should be understood that the specific embodiments shown and described by way of illustration are in no way intended to be limiting. Furthermore, the invention has been described with reference to specific preferred embodiments, but variations within the spirit and scope of the invention will occur to those skilled in the art. It should be noted that the above examples have been provided for purposes of explanation only and are in no way to be construed as a limitation of the present invention. Although the present invention has been described with reference to exemplary embodiments, it is understood that the words used herein are words of description and illustration rather than words of limitation. Changes may be made in the scope of the appended claims, as presently described and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to specific means, materials, and embodiments, the present invention is not intended to be limited to the specific details disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods, and uses as included within the scope of the appended claims.