The present invention relates to a multiple-positioning mechanical shifting system and method for use in hydrocarbon wells and more particularly to a shifting tool for manipulation of a mechanical sliding sleeve valve capable of multiple operational positions.
Sliding sleeve valves have been used in tubing string for oil and gas wells to control fluid flow between the tubing string and the well annulus during circulation or production. The valves contain an inner sliding sleeve having a port that can be shifted to an opened position in alignment with a port in the outer valve body to permit fluid to flow from the tubing string to the well annulus. Shifting the sliding sleeve to a closed position blocks the port in the valve body to prevent the fluid from flowing into the well annulus. Mechanical sliding sleeve valves are manipulated by shifting tools customarily deployed on wireline or slickline. Shifting tools move the sliding sleeve to either the fully shifted up or fully shifted down position. Accordingly, sliding sleeve valves customarily have only two positions opened or closed.
Sliding sleeve valves have been developed that have a third position known as the equalizing position. The equalizing position is located intermediate of the opened and closed positions. In these valves, a smaller diameter equalizing port is provided in the inner sliding sleeve. The equalizing port serves to balance the tubing pressure and the annulus pressure before fully opening the valve in order to reduce the likelihood of a pressure surge as the valve is fully opened. The process of equalizing the pressures is carried out by shifting the sliding sleeve to a position where the equalizing port in the sliding sleeve is in fluid communication with the port of the valve body. Shifting tools have been produced to manipulate such sliding sleeve valves. U.S. Pat. No. 5,305,833, which is incorporated herein by reference, describes a shifting tool capable of positioning a sliding sleeve valve in a fully closed position, equalizing position, and fully opened position.
Multi-positioned sliding sleeve valves have also been developed. U.S. Pat. No. 6,722,439, which is incorporated herein by reference, describes a downhole choke valve in the form of a hydraulically controlled sliding sleeve valve operable in a plurality of positions including fully opened, fully closed and intermediate positions.
Despite the development of shifting tools that can position a sliding sleeve valve in three distinct positions, fully closed, equalizing, and fully opened, the need still exists for a shifting tool that can position a mechanical sliding sleeve valve in multiple positions and which can be used in conjunction with a multiple position mechanical choke valve.
It is an object of the present invention to provide mechanical shifting system that functions as a multiple position mechanical choke valve.
It is a further object of the present invention to provide a shifting tool for use with a multiple position mechanical sliding sleeve valve.
It is a further object of the present invention to provide a multiple position mechanical choke valve.
These objects and other objects and advantages of the present invention are achieved by a novel multiple-position shifting system which includes a shifting tool for use with a mechanical sliding sleeve valve deployed in a tubing string of a hydrocarbon well. The sliding sleeve valve may include an internal sliding sleeve and an outer valve body. The shifting tool may include a top sub. A shifting tool key may be positioned on the top sub. The shifting tool key may be radially expandable to engage the internal sliding sleeve to enable shifting of the internal sliding sleeve relative to the outer valve body by displacement of the shifting tool within the sliding sleeve valve during valve shifting operations. The shifting tool key may also be radially retractable to disengage from the internal sliding sleeve to enable release of the sliding sleeve valve from the shifting tool during valve release operations. The shifting tool may also include a bottom sub.
The shifting tool may include a reciprocating assembly interconnecting the top sub and the bottom sub. The reciprocating assembly may include an inner mandrel and an outer housing disposed about the inner mandrel. The outer housing may have a biasing means to reciprocate the outer housing in a first direction during the valve shifting operations. The outer housing may also have an actuating means to cause reciprocation of the outer housing in a second direction during said valve release operations. The actuating means may operatively cooperate with the shifting tool key during valve release operations to disengage the shifting tool key from the internal sliding sleeve to place the internal sliding sleeve at a spatial position relative to said valve body. The spatial position may be selected from a plurality of possible spatial positions.
The shifting tool key may be retained on the top sub by a pair of retainers detachably affixed to the top sub. The top sub and the bottom sub may each be threadedly connected to the inner mandrel of the reciprocating assembly. The outer housing of the reciprocating assembly may be moveably connected to the inner mandrel of the reciprocating assembly.
The shifting tool key may have an outer profile that includes an engagement shoulder. The engagement shoulder may cooperate with a mating shoulder on the internal sliding sleeve. The cooperation between the engagement shoulder and the mating shoulder may enable the engagement of the shifting tool key with the internal sliding sleeve during valve shifting operations.
The outer profile of the shifting tool key may also include a releasing shoulder. The releasing shoulder may be actuated to radially retract the shifting tool key to disengage the engagement shoulder from the mating shoulder during valve release operations. The releasing shoulder may be actuated by reciprocation of the outer housing in the second direction.
The shifting tool key may also include biasing means. The biasing means may cause the radial expansion of the shifting tool key. The shifting tool key may have a recess. The recess may house or contain the biasing means. The biasing means may be a spring.
The reciprocating assembly may likewise include a recess. The recess may house or contain the biasing means of the reciprocating assembly. The biasing means may be a spring.
The sliding sleeve valve may contain an end sub. When the actuating means on the outer housing of the reciprocating assembly engages the end sub (during valve release operations), the outer housing is reciprocated in the second direction to disengage the shifting tool key from the internal sliding sleeve. Reciprocation in the second direction occurs by compression of the biasing means housed in the reciprocating assembly.
The actuating means may be any device that is capable of engaging or cooperating against the end sub to move or reciprocate the outer housing in the second direction. For example, the actuating means may be one or more collets.
The feature of the present invention wherein the internal sliding sleeve may be released at multiple positions relative to the outer valve body may be achieved based on a specified distance or length between the releasing shoulder of the shifting tool key and the actuating means on the outer housing of the reciprocating assembly. Such distance or length may be determinative of the spatial positioning of the internal sliding sleeve relative to the outer valve body. Accordingly, the shifting tool of the present invention may include a means to adjust the distance or length between the releasing shoulder and the actuating means to achieve multiple positioning of the internal sliding sleeve.
In one embodiment of the present invention, the mechanical sliding sleeve valve is a mechanical choke valve in which the internal sliding sleeve includes a plurality of a series of ports capable of providing fluid communication of the tubing string fluid there-through. Each of the plurality of the series of ports may provide a different flow rate and/or volume of the tubing string fluid flowing there-through. The spatial position selected for the internal sliding sleeve as described above may comprise one of the plurality of the series of ports, which are aligned with one or more ports in the outer valve body.
In another embodiment of the present invention, a shifting tool is provided for use with a mechanical sliding sleeve valve deployed in a tubing string of a hydrocarbon well. The mechanical sliding sleeve valve may include an internal sliding sleeve, an outer valve body, and an end sub. The shifting tool may include a top sub. The shifting tool may also include a shifting tool key positioned on the top sub. The shifting tool key may include an outer profile having an engagement shoulder and a release shoulder. The shifting tool key may also include a biasing means to radially expand the shifting tool key for engagement of the engagement shoulder with a mating shoulder of the internal sliding sleeve to enable shifting of the internal sliding sleeve relative to the outer valve body by displacement of the shifting tool within the sliding sleeve valve during valve shifting operations. The bias means also permit the radial retraction of the shifting tool key to disengage the engagement shoulder from the mating shoulder to enable release of the sliding sleeve valve from the shifting tool during valve release operations.
The shifting tool may also have a bottom sub. A reciprocating assembly may interconnect the top and bottom subs. The reciprocating assembly may include an inner mandrel and an outer housing disposed about the inner mandrel. The outer housing may have an upper end and a lower end. The outer housing may also have a biasing means to reciprocate the outer housing in a first direction during the valve shifting operations. The outer housing may include an actuating means to cause reciprocation of the outer housing in a second direction during the valve release operations by compressing the biasing means of the reciprocating assembly when the actuating means engages the end sub. The actuating means may operatively cooperate with the shifting tool key during valve release operations to cause the upper end of the outer housing to collapse the release shoulder to disengage the engagement shoulder from the mating shoulder and thereby place the internal sliding sleeve at a spatial position relative to said valve body. The spatial position may be selected from three or more possible spatial positions based on a pre-selected distance between the actuating means and the release shoulder. In this embodiment, the actuating means may be one or more collets.
The shifting tool may be deployed on wireline and preferably slickline. However, the shifting tool could also be deployed on coiled tubing or pipe string.
The present invention also is directed to a novel method of operating a mechanical sliding sleeve valve having an internal sliding sleeve, an outer valve body and an end sub for selective placement of the internal sliding sleeve at a spatial position relative to the valve body. The spatial position may be selected from any number of possible spatial positions or a plurality of possible spatial positions.
The method includes providing a shifting tool as set forth and described above. The method also includes pre-selecting the distance between the actuating means on the outer housing of the reciprocating assembly and the release shoulder on the shifting tool key. The shifting tool is deployed down a tubing string. The tubing string may include or contain the mechanical sliding sleeve valve. The method includes the step of causing the engagement shoulder on the shifting tool key to engage the mating shoulder on the internal sliding sleeve to operatively connect the shifting tool and the internal sliding sleeve. The method involves shifting the internal sliding sleeve relative to the valve body by displacing the shifting tool within the mechanical sliding sleeve valve. The outer housing is reciprocated in the second direction by causing the actuating means to engage the end sub so as to affect compression of the biasing means in the reciprocating assembly. The method includes the step of causing the upper end of the outer housing to collapse the release shoulder to disengage the engagement shoulder from the mating shoulder thereby releasing the internal sliding sleeve from the shifting tool at a selected spatial position relative to the valve body. The spatial position where the internal sliding sleeve is released may be pre-determined by selecting a specified distance between the actuating means and the release shoulder. The selected spatial position of the internal sliding sleeve achieved may be a fully closed position, a plurality of intermediate positions, an equalizing position, or a fully opened position.
The step of pre-selecting the distance between the actuating means and the release shoulder may be undertaken by: (i) adjusting the length of the outer housing where the actuating means is at a fixed position on the outer housing; (ii) adjusting the position of the actuating means on the outer housing where the actuating means is detachably fixed to the outer housing; or (iii) affixing a selected outer housing having a specified length and a fixed actuating means thereon (the selected outer housing may be chosen from among a plurality of outer housings each having a different length and a fixed actuating means thereon).
The shifting tool of the present invention may be used with a mechanical choke valve deployed in a tubing string of a hydrocarbon well. The mechanical choke valve may include an internal sliding sleeve. The internal sliding sleeve may have a mating shoulder for operable engagement with the shifting tool as described above. The internal sliding sleeve may have a plurality of a series of ports capable of providing fluid communication of a tubing string fluid there-through. Each of the plurality of series of ports may provide a different flow rate and/or volume of the tubing string fluid flowing there-through. The mechanical choke valve may also include an outer valve body disposed about the internal sliding sleeve. The outer valve body may have one or more ports capable of providing fluid communication of the tubing string fluid there-through. Preferably, each of the plurality of series of ports in the internal sliding sleeve may be capable of being selectively aligned with one or more ports of the outer valve body to provide fluid communication of the tubing string fluid to the well annulus by displacement of the shifting tool as described hereinabove.
Each embodiment of the shifting tool described above may be used in connection with the operation of the mechanical choke valve.
The mechanical choke valve of the present invention may also include an outer valve body that has one or more detent grooves. The internal sliding sleeve may be provided with one or more locking collets. The locking collect may be snapped into positioned within a corresponding detent groove to lock the internal sliding sleeve in place when the internal sliding sleeve is released from the shifting tool. The locking of the collect with the detent grooves helps prevent any unintentional shifting of the internal sliding sleeve due to fluid pressures in the tubing string.
In an embodiment of the mechanical choke valve, the plurality of series of ports of the internal sliding sleeve include: (1) a first series of ports that when aligned with one or more ports of the outer valve body place the mechanical choke valve in a fully opened position; (2) a second series of ports that when aligned with one or more ports of the outer valve body place the mechanical choke valve in a first intermediate position; (3) a third series of ports that when aligned with one or more ports of the outer valve body place the mechanical choke valve in a second intermediate position.
With reference to the figures where like elements have been given like numerical designation to facilitate an understanding of the present invention, and in particular with reference to the embodiment of the present invention illustrated in
Shifting tool key 14 may include recess 20 that accommodates biasing means 22. Biasing means 22 are capable of causing the radial, outward expansion of shifting key 14. Biasing means 22 may be a spring such as a grasshopper spring or butterfly spring. Shifting tool key 14 may include an outer profile containing engagement shoulder 28 and releasing shoulder 30. When radially expanded, the outer profile of shifting tool key 14 cooperates with a mating profile on the inner surface of internal sliding sleeve 44 of mechanical sliding sleeve valve 42. For example, engagement shoulder 28 may cooperate with mating shoulder 52 of internal sliding sleeve 44 as shown in
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In
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The releasing mechanism of shifting tool 10 may be employed to selectively place sliding sleeve 44 at a spatial position relative to outer valve body 50. Such selective placement of sliding sleeve 44 is accomplished by varying the distance or length between collet 36 of outer housing 34 and releasing shoulder 30 of shifting tool key 14. For example, a greater distance between collet 36 and releasing shoulder 30 would mean that sliding sleeve 44 will be released, and therefore placed, at a higher location within sliding sleeve valve 42. A lesser distance between collet 36 and releasing shoulder 30 would mean that sliding sleeve 44 will be released, and therefore placed, at a lower location within sliding sleeve valve 42. Any number of placement positions is achievable with shifting tool 10 such as fully opened, fully closed, or one or more intermediate positions between fully opened and fully closed.
Varying the distance between collet 36 on outer housing 34 and releasing shoulder 30 of shifting tool key 14 may be accomplished in a number of ways. For instance, outer housing 34 could be made so that its length could be adjusted to account for variable distances between collet 36 and releasing shoulder 30. One or more segments of outer housing 34 could be added to increase the overall length of outer housing 34 or removed to decrease the overall length of outer housing 34. Alternatively, outer housing could be made so that the positioning of collet 36 on outer housing 34 could be adjusted to account for variable distances between collet 36 and releasing shoulder 30. Collet 36 could be detachably connected to outer housing 34 and movable in a downward direction on outer housing 34 to increase the distance between collet 36 and releasing shoulder 30 or moveable in an upward direction on outer housing 34 to decrease the distance between collet 36 and releasable shoulder 30. As another alternative, outer housing 34 could be made in multiple lengths. If an operator desired to increase the distance between collet 36 and releasable shoulder 30, the operator could configure shifting tool 10 with one of the outer housings 34 having a greater length. Conversely, if an operator desired to decrease the distance between collet 36 and releasable shoulder 30, the operator could configure shifting tool 10 with one of the outer housings 34 having a shorter length.
As shown in
Shifting tool 10 may be used with a mechanical choke valve that includes a sliding sleeve with one or more series of different numbered and/or sized ports that could be selectively positioned in fluid communication with the ports of the outer valve body for controlled fluid flow into the well annulus.
With reference to
Depending on the desired flow rate and/or volume of tubing string fluid to be flowed into the well annulus, an operator may choose to place mechanical choke valve 100 in a fully opened position in which case the second series of ports 114, 116, 118 would be positioned in fluid communication with ports 122, 124, 126 of outer valve body 102. The operator may decide to place mechanical choke valve 100 in a first intermediate position (e.g., partially opened) in which case the first series of ports 110, 112 would be positioned in fluid communication with ports 112, 124, 126 of outer valve body 102 (i.e., between seals 106, 108) The operator may decide to place mechanical choke valve 100 in a second intermediate position (partially closed) in which case the third series of port 120 would be positioned in fluid communication with ports 112, 124, 126 of outer valve body 102. The operator may decide to place mechanical choke valve 100 in a fully closed positioned in which case a portion of internal sliding sleeve with no ports would be positioned to prevent fluid communication with ports 122, 124, 126 of outer valve body 102 (i.e., positioned between seals 106, 108 to block fluid communication to ports 122, 124, 126).
To achieve differing flow rates and/or volumes, each series of ports may have different numbers of ports, different sized ports or both. Within a series having two or more ports, each port mat be differently sized. The number and size of ports will depend in the desired flow rate and/or volume to be achieved.
While preferred embodiments of the present invention have been described, it is to he understood that the embodiments described are illustrative only and that the scope of the invention is to be defined solely by the appended claims when accorded a full range of equivalents, many variations and modifications naturally occurring to those skilled in the art from a perusal hereof.