CA2820283A1 - Valve and method for hydraulic fracturing - Google Patents
Valve and method for hydraulic fracturing Download PDFInfo
- Publication number
- CA2820283A1 CA2820283A1 CA2820283A CA2820283A CA2820283A1 CA 2820283 A1 CA2820283 A1 CA 2820283A1 CA 2820283 A CA2820283 A CA 2820283A CA 2820283 A CA2820283 A CA 2820283A CA 2820283 A1 CA2820283 A1 CA 2820283A1
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- CA
- Canada
- Prior art keywords
- valve
- outer housing
- gate
- opening
- setting sleeve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims description 22
- 239000012530 fluid Substances 0.000 claims abstract description 45
- 239000004568 cement Substances 0.000 claims abstract description 20
- 238000004891 communication Methods 0.000 claims abstract description 12
- 239000000945 filler Substances 0.000 claims description 7
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 230000000903 blocking effect Effects 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000005086 pumping Methods 0.000 claims 1
- 238000009826 distribution Methods 0.000 description 4
- 238000007373 indentation Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000009877 rendering Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009172 bursting Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/063—Valve or closure with destructible element, e.g. frangible disc
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/10—Valve arrangements for boreholes or wells in wells operated by control fluid supplied from outside the borehole
- E21B34/102—Valve arrangements for boreholes or wells in wells operated by control fluid supplied from outside the borehole with means for locking the closing element in open or closed position
- E21B34/103—Valve arrangements for boreholes or wells in wells operated by control fluid supplied from outside the borehole with means for locking the closing element in open or closed position with a shear pin
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B2200/00—Special features related to earth drilling for obtaining oil, gas or water
- E21B2200/06—Sleeve valves
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Details Of Valves (AREA)
Abstract
A valve for use in fracing through cement casing in a wellbore has an outer housing with openings, a setting sleeve with openings disposed inside the outer housing, and a gate positioned in the annulus between the outer housing and the setting sleeve.
The outer surface of the outer housing has at least one channel and the outer housing openings are situated in a raised portion of the outer surface. The gate is slideable in the annulus between a first and second position. In the first position, the gate blocks fluid communication between the openings in the outer housing and the setting sleeve. In the second position, fluid can flow between the openings. The valve is configured to help minimize the exposure of the gate to cement and wellbore debris, and to help minimize the thickness of the cement sheath adjacent the outer housing openings.
The outer surface of the outer housing has at least one channel and the outer housing openings are situated in a raised portion of the outer surface. The gate is slideable in the annulus between a first and second position. In the first position, the gate blocks fluid communication between the openings in the outer housing and the setting sleeve. In the second position, fluid can flow between the openings. The valve is configured to help minimize the exposure of the gate to cement and wellbore debris, and to help minimize the thickness of the cement sheath adjacent the outer housing openings.
Description
Valve and Method for Hydraulic Fracturing Field The invention relates to a valve and a method for hydraulically fracturing (also called fracing) a wellbore, particularly for the purpose of producing hydrocarbons.
Background In some wellbore completion operations, a valve is incorporated into a casing string of the well. When the valve is in a closed position, the valve allows cement to flow therethrough inside the casing string. When the valve is in an open position, the valve allows fracturing fluid to flow through the cement casing to fracture the formation near the valve. Using this type of hydraulic frac valve may eliminate the need for perforating the cement casing prior to fracturing.
Commonly used mechanisms for opening the hydraulic frac valve are often at least partially exposed to the flow of cement inside the casing string or in the annulus between the casing string and the wellbore wall. The exposure to cement or other debris can cause the opening mechanism to become jammed thereby rendering the valve inoperable after the cementing process has been completed.
Sumrnary of the Invention In accordance with a broad aspect of the present invention, there is provided a valve having a closed position and an open position, the valve comprising: an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel; a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, and at least one opening; and a gate in an annulus folined between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate blocking fluid communication between the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the closed position, and allowing fluid flow between WSLega1,069309 \00004 \8806813v3 the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the open position.
In accordance with another broad aspect of the present invention, there is provided a method for actuating a valve for treating a subterranean formation, the method comprising: flowing a fluid through the valve, the valve comprising: an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel; a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, at least one opening, and a burst plug in a passageway extending between the outer surface and the inner surface; and a gate in an annulus formed between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate movable axially in the annulus between a first position and a second position; rupturing the burst plug at a selected fluid pressure; flowing fluid through the passageway into the annulus to the gate;
moving the gate from the first position to the second position; exiting fluid through the at least one opening in the at least one opening in the setting sleeve and the at least one opening in the outer housing.
It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Brief Description of the Drawings Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:
Figure 1 is a perspective view of a valve according to one embodiment of the present invention;
WSLega1\069309\00004 \8806813v3 Figure 2 is a side elevation view of the valve; and Figures 3, wherein Figures 3a and 3b are axial cross-sectional views of the valve in a closed position and an open position, respectively.
Detailed Description of Various Embodiments The description that follows and the embodiments described therein are provided by way of illustration of an example, or examples, of particular embodiments of the principles of various aspects of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention in its various aspects. In the description, similar parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features.
Referring to Figures 1 to 3, a valve is shown and a method is described for hydraulically fracturing a wellbore using the valve. A valve 10 of an embodiment of the present invention comprises an outer housing 12, a gate 14, and a setting sleeve 16.
Outer housing 12 is a tubular member having an outer surface and an inner surface defining an inner bore that extends axially from a first end to a second end of the outer housing.
Outer housing 12 may be threaded at both ends, and the threading may form pin or box ends, for connection to the casing string. The casing string is preferably formed to hold pressure. Therefore, any connection should, in the preferred embodiment, be selected to be substantially pressure tight. Preferably, the casing string is resistant to fluid flow outwardly therefrom except through (i) open ports in valve 10 when in an open position and (ii) its lower end when it is open.
In one embodiment, outer housing 12 has two parts: a top sub 18 and a bottom sub 20, both of which are tubular members each having an outer surface and an inner surface defining an axially extending inner bore. A second end of the top sub is coupled to a first end of the bottom sub and the two subs may be connected in various ways. For example, the second end of the top sub is internally threaded and the first end of the bottom sub is WSLega1\069309 \00004 \8806813v3 externally threaded, such that the two ends can be threadedly connected to each other to form outer housing 12. A first end of the top sub and a second end of the bottom sub are the first and second ends of the outer housing, respectively, and each may be threaded to form pin or box ends for connection to the casing string. The inner and/or outer surfaces of the top and bottom subs may include annular grooves 21 for receiving suitable annular seals, such as o-rings, for fluidly sealing an interface between two surfaces.
A recess is provided on the inner surface of the bottom sub for accommodating a snap ring 23.
The outer surface of the outer housing 12 includes at least one channel 22 for helping to direct and/or facilitate the flow of fluid therethrough along the outer surface of the outer housing, when valve 10 is in use. In one embodiment, the channel is an indentation on the outer surface of the outer housing, including for example a slot and/or groove. In another embodiment, the channel is formed between at least two radially outwardly projecting portions and/or members on the outer surface of the outer housing. For example, the outer surface of the outer housing may include a plurality of ridges that define a plurality of channels therebetween. The channel has a base, which is a surface that is indented compared to surrounding surfaces. In other words, the base is closer to the central long axis of the outer housing than the other surfaces around adjacent to the base.
The channel may be linear in shape and may be formed to extend lengthwise on the outer surface of the outer housing. In a further embodiment, the channel may be formed to be substantially parallel to the long axis of the inner bore of the outer housing. In another embodiment, a portion of the channel may be curved, C-shaped, S-shaped, etc.
Further, the depth of the channel, which is defined by the minimum distance between the base and an adjacent radially outwardly-facing surface, may be substantially uniform or may vary along the length of the channel. In addition to its shape, the length, width, and depth of the channel may vary depending on the characteristics of the fluid to flow therethrough and/or the overall dimensions of the outer housing. The number of channels formed on the outer surface of the outer housing may vary and may depend on the configuration of the other components of the valve 10, which are described in detail hereinbelow. In one embodiment, six channels are provided on the outer surface of the outer housing wherein the channels are substantially equidistance apart around the outer circumference of the outer housing.
WSLegal\ 069309 \00004'.8806813v3 Outer housing 12 has at least one opening 24 that allows fluid communication between its inner and outer surfaces. In one embodiment, the opening is positioned between two adjacent channels on the outer surface of the outer housing. In a further embodiment, the opening is formed in a portion of the outer surface that is furthest away from the central long axis of the outer housing. In other words, the base of the at least one channel is closer to the long axis than the portion where the at least one opening is positioned. In one embodiment, outer housing 12 has a plurality of openings 24 forming a single row around the circumference of the outer housing. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 24. Of course, the number, spacing, and distribution of openings 24 in outer housing 12 may vary.
The inner surface of outer housing 12 may include a shoulder 25, between the edge of opening 24 that is closest to the second end of the outer housing and the second end of the outer housing.
In the illustrated embodiment, a portion of the opening is covered with a cover plate 26.
Cover plate 26 has an opening 28 and is attachable to the outer housing in various ways, including for example by fasteners, mechanical engagement between the cover plate and the outer housing, adhesives, bonding, welding, etc. or a combination thereof.
In one embodiment, cover plate 26 is substantially rectangular and has substantially planar outer and inner surfaces. The shape of cover plate 26 may vary and may depend on the shape of the opening 24 in the outer housing.
In a further embodiment, cover plate 26 includes holes near its ends and outer housing 12 includes holes 30 above the opening 24 and holes 32 below opening 24, such that holes are closer to top sub 18 than holes 32. Cover plate 26 may be secured to the outer housing by placing plate 26 over opening 24, aligning the holes in the cover plate and 25 holes 30, 32, and fastening fasteners 33, 34 through the aligned holes above and below opening 24, respectively. The inner surface of cover plate 26 directly faces opening 24 when plate 26 is attached to outer housing 12. In a further embodiment, fasteners 33, 34 are selected such that when they are fastened in both the holes in the cover plate and holes 30, 32, the tops of the fasteners are substantially flush with or slightly recessed 30 from the outer surface of cover plate 26.
WSLega1\069309 \00004 ',8806813v3 In one embodiment, the outer housing and cover plate are configured to mechanically engage one another. For example, the outer housing may include dovetail grooves at the side edges of opening 24 into which the side edges of cover plate 26 can slide, thereby further securing the cover plate in place over opening 24.
In another embodiment, part of the outer surface of outer housing 12 near opening 24 is recessed for receiving the edges of cover plate 26. The recess may have a depth that is substantially the same as the thickness of cover plate 26, such that when cover plate 26 is received in the recess, the outer surface of cover plate 26 is substantially flush with the non-recessed outer surface of outer housing 12.
Cover plate 26 further includes an aperture 36 for receiving a shear screw 38 therein.
In one embodiment, cover plate 26 is made of high impact strength material, including for example 4140 110K MYS alloy steel.
In one embodiment, outer housing 12 has a plurality of openings 24 and cover plates 26 are installed thereon to cover a portion of each of the openings, such that openings 28 forms a single row around the circumference of the outer housing. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 28. Of course, the number, spacing, and distribution of openings 28 on outer housing 12 may vary.
In another embodiment, the outer housing is configured such that the addition of a cover plate is not necessary. For example, opening 24 in the outer housing may be sized and positioned in a similar manner as opening 28, as described herein, such that opening 24 can function substantially the same as opening 28, thereby rendering cover plate 26 unnecessary.
Setting sleeve 16 is a tubular member having an outer surface and an inner surface defining an inner bore that extends axially from a first end to a second end of the setting sleeve. The setting sleeve extends axially in the inner bore of the outer housing, between the first end of the top sub and the second end of the bottom sub, such that fluid can flow WSLegat,069309',00004' 8806813v3 between the first and second ends of the outer housing via the inner bore of the setting sleeve. Setting sleeve 16 may share the same central long axis as outer housing 12.
Setting sleeve 16 has at least one opening 40 that allows fluid communication between its inner and outer surfaces. In one embodiment, setting sleeve 16 has a plurality of openings 40 forming a single row around the circumference of the setting sleeve. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 40. Of course, the number, spacing, and distribution of openings 40 in setting sleeve 16 may vary.
The outer surface of setting sleeve 16 may include a shoulder 43. Setting sleeve 16 also includes a burst plug 41 (sometimes also referred to as a rupture disc, bursting disc, or burst diaphragm) positioned in a passageway extending between the inner and outer surfaces of the setting sleeve. When intact, burst plug 41 restricts fluid communication between the inner and outer surface of the setting sleeve via the passageway.
Once burst plug 41 is ruptured, the passageway opens up, allowing fluid to flow between the inner and outer surfaces of the setting sleeve. The setting sleeve may be configured such that the passageway (and therefore the burst plug) is situated near one end thereof.
In one embodiment, the inner surface of outer housing 12 includes shoulders 42 and 44 near the first end of the top sub and the second end of the bottom sub, respectively.
Shoulders 42, 44 can be formed in any way as by casting, milling, etc. the wall material of the outer housing or by threading parts together. Setting sleeve 16 is contained inside the outer housing, between the first end of the top sub and the second end of the bottom sub, by engaging the shoulders 42 and 44. The outer surface of setting sleeve 16 may optionally have a threaded portion at the first end for connecting to a threaded portion on the inner surface of the top sub, thereby securing the setting sleeve inside the outer housing. A portion of the outer surface of the setting sleeve and a portion of the inner surface of the outer housing are spaced apart to define an annulus 46.
In a further embodiment, holes 32 extend from the outer surface of outer housing 12 to adjacent the outer surface of setting sleeve 16 and the outer surface of setting sleeve 16 includes indentations that are aligned with holes 32 for receiving the feet of fasteners 34.
WSLega1\069309,00004\8806813v3 When fasteners 34 are fastened through the holes in the cover plate and holes 32, their feet extend into and engage the indentations in the outer surface of setting sleeve 16, thereby securing setting sleeve 16 to the outer housing 12, which helps prevent setting sleeve 16 from rotating relative to the outer housing and assists in aligning the holes in the cover plate, the gate, and the setting sleeve when valve 10 is in the open position, as described in more detail hereinbelow.
The gate 14 is provided in the annulus 46. The gate is a tubular member having an outer surface and an inner surface defining an inner bore that extends axially from a first end to a second end of the gate. The length of gate 14 is shorter than the length of annulus 46 such that gate 14 is slideable axially within annulus 46 between a first position and a second position. In the first position, gate 14 is closer to the first end of the top sub than in the second position. Gate 14 has at least one opening 49 that allows fluid communication between its inner and outer surfaces. In one embodiment, gate 14 has a plurality of openings 49 forming a single row around the circumference of the gate. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 49. Of course, the number, spacing, and distribution of openings 49 in gate 14 may vary. The inner and outer surfaces of gate 14 may include annular recesses 50 for receiving suitable seals, such as o-rings, so that fluid bypass between the gate and the setting sleeve and outer housing is substantially prevented. The outer surface of gate 14 includes an annular groove 52 for receiving the snap ring 23. Gate 14 further includes a block 56, which is a raised surface or a radially outwardly projecting member on the outer surface for engaging with the inner surface of cover plates 26 or outer housing 12.
Block 56 may be a single ring-shaped component or one or more spaced-apart platforms.
Block 56 may be a separate component that is attached to the outer surface of gate 14 or formed with the gate 14 as a single part during manufacturing. In one embodiment, the interface between the gate 14 and block 56 includes a tongue and groove joint 60 to provide mechanical engagement between the two parts. There are of course many ways to attach block 56 to the outer surface of gate 14, including for example by fasteners, adhesives, bonding, welding, friction fitting, etc. Recesses are provided on the outer surface of block 56 for receiving a portion of the shear screws 38.
WSLegaH)69309\00004..8806813v3 A breakable filler may optionally be provided at openings 28 of cover plates 26 to substantially shield block 56 from the space adjacent the outer surface of cover plates.
The filler may be disposed adjacent to the outer surface of the block. The filler may be made of plastic and/or a composite solid. Additionally or alternatively, a solid or gel-type gasket may be provided for substantially sealing the cover plates against the block and outer housing. The gasket may be made of silicone or a composite material. The material of both the filler and the gasket is selected so that it breaks and disintegrates when it is exposed to fluids at and above a certain fluid pressure and/or flow rate (e.g.
fluid pressure and/or flow rate of the fracing fluid during the fi-acing process).
The components of valve 10 may be constructed of any suitable material, such as plastic, aluminum, steel, ceramic, and so on, with consideration as to the conditions in which they must operate.
Valve 10 is transitionable from a closed position to an open position. In the closed position, burst plug 41 in setting sleeve 16 is intact and gate 14 is in the first position, wherein the gate is positioned in a portion of the annulus that is closer to the first end of the outer housing, and wherein openings 49 are sandwiched in between the inner surface of the outer housing and the outer surface of setting sleeve 16 and are not in communication with openings 40 and openings 28, such that no fluid can flow through openings 49. When gate 14 is in the first position, block 56 blocks openings 24, or openings 28 if cover plates 26 are used. In one embodiment, cover plates 26 are used and, when the gate is in the first position, block 56 engages the inner surface of cover plates 26 and blocks openings 28. Also, in the first position, openings 40 are blocked by a portion of the inner surface of the gate 14. Therefore, in the closed position, gate 14 provides a fluid barrier between openings 40 and openings 28 (or openings 24 if no cover plates are used), such that no fluid can flow between the outer surface of the outer housing 12 and the inner bore of setting sleeve 16 via openings 40. In the closed position, block 56 is attached to cover plates 26 (or outer housing 12 if cover plates are omitted) by shear screws 38, which helps maintain the gate in the first position before the valve 10 is actuated. The first end of the gate 14 may abut against shoulder 43 when the gate is in the first position. Shoulder 43 helps prevent gate 14 from sliding beyond a certain point in WSLegal \ 069309 \ 00004%8068130 ¨ 10 -the annulus towards the first end of the outer housing. Seals are provided in annular recesses 50 such that the interface between the gate and each of the outer housing and the setting sleeve is fluidly sealed. In the closed position, the annulus is fluidly isolated from the inner bore of the setting sleeve and the outer surface of the outer housing. In addition, the space in the annulus adjacent to the first end of the gate and the space in the annulus adjacent to the second end of the gate are fluidly sealed from each other.
In the open position, burst plug 41 in setting sleeve 16 is ruptured, shear screws 38 are sheared, and gate 14 is in the second position, wherein the gate is positioned in a portion of the annulus that is closer to the second end of the outer housing, and wherein openings 49 are in communication with openings 40 and openings 24 (or openings 28 if cover plates 26 are used), such that fluid can flow between the inner bore of the setting sleeve and the outer surface of the outer housing through all three openings 28, 40, and 49. In one embodiment, the openings 28, 40, and 49 are substantially aligned when the valve is in the open position. While in the illustrated embodiment, openings 28, 40 and 49 are shown to be similarly shaped and sized, it can be appreciated that the size and shape of openings 28, 40 and 49 may be different from one another. With the burst plug ruptured, the space in the annulus adjacent to the first end of the gate is in fluid communication with the inner bore of the setting sleeve. In the open position, shear screws 38 are sheared so that block 56 is no longer attached to cover plates 26 (or outer housing 12 if cover plates are omitted), which allows the gate to move to the second position after the valve 10 is actuated. When gate 14 is in the second position, block 56 is shifted towards the second end of the outer housing, thereby unblocking openings 24, or openings 28 if cover plates 26 are used. In one embodiment where cover plates 26 are used, block 56 is shifted to engage a portion of the inner surface of cover plates 26 that does not contain openings 28. Also, in the second position, openings 49 in gate 14 are shifted towards the second end of the outer housing to be in communication with openings 40 and 28 (or openings 24 if no cover plates are used). Therefore, in the open position, the position of gate 14 allows fluid to flow between the outer surface of the outer housing 12 and the inner bore of setting sleeve 16 via the openings 28, 40, and 49. In the open position, a portion of snap ring 23 is snapped into groove 52 to help maintain the gate in the second position.
The second end of the gate may be beveled to assist in opening up snap ring 23 and to WSLegah069309 \00004 \88068130 =
¨ 11 -facilitate the sliding of snap ring 23 on to the outer surface of the gate towards groove 52.
The second end of the gate 14 may abut against shoulder 25 when the gate is in the second position. Shoulder 25 helps prevent gate 14 from sliding beyond a certain point in the annulus towards the second end of the outer housing.
In use, valve 10 may be connected to the casing string by the first and second ends of the outer housing. One or more valves may be incorporated into the casing string.
In one embodiment, when the casing string is downhole, the first end of the outer housing is the upper end and the second end being the lower end, with the upper end being closer to the wellbore opening at surface than the lower end. In an alternative embodiment, valve 10 can still operate when installed into the casing string "upside down," wherein when the casing string is downhole, the second end of the outer housing is the upper end and the first end of the outer housing is the lower end.
Before deployment into the wellbore, valve 10 is in the closed position, wherein the flow path between openings 28 and 40 is blocked by block 56. After the casing string along with valve 10 is deployed in the wellbore, cement is pumped down inside the casing string and out the lower end of the casing string into the annulus between the wellbore wall and the outer surface of the casing, a procedure which is known to those skilled in the art. After the cement flow is terminated, a wiper plug or other device is pumped down to wipe the inner bore wall of the casing and valve substantially clean of residual cement.
When the wiper plug or other device has latched or sealed in the bottom hole assembly, fracturing fluid is pumped down the through coiled tubing (and/or the coiled tubing is rotated) to set a straddle packer attached to the coiled tubing at either end of the valve to seal off the valve. The straddle packer isolates the fracture fluid inside the inner bore of the valve. As fracturing fluid is continuously pumped into the coiled tubing, fluid pressure inside the isolated inner bore of the valve is increased to rupture burst plug 41 at a predetermined pressure, thereby actuating the valve.
After burst plug 41 is ruptured, fracturing fluid inside the casing string and therefore the inner bore of setting sleeve 16 flows into the space adjacent the first end of gate 14 inside annulus 46. As more fluid flows into annulus 46 near the first end of the gate, the WSLegal\ 069309 \00004 \8806813v3 increase in fluid pressure exerts a force on the gate in the direction opposite the burst plug 41, for example in the direction of the lower end of the outer housing as shown in the illustrated embodiment (or in the direction of the upper end if the valve is installed upside down). When the force on the gate reaches a predetermined threshold, the shear screws 38 are broken, which slides the gate axially in annulus 46. While the gate slides toward the lower end, any air or fluid in the space adjacent the second end of the gate in annulus 46 can escape via openings 28. When the second end of the gate encounters snap ring 23, the snap ring is urged by the gate to expand and slide on to the outer surface of the gate.
Once the snap ring snaps on to groove 52, the valve 10 is in the open position, wherein the flow path between openings 28 and 40 is unblocked, and openings 28 and 40 are in fluid communication via openings 49. In the open position, fracturing fluid is allowed to exit the valve via the openings 28, 40, and 49, in order to crack the cement sheath and fracture the formation adjacent to the outer surface of the valve near openings 28.
As described above, valve 10 may be configured to have screws 34 extend into and engage indentations in the outer surface of setting sleeve 16 to assist in maintaining the alignment of openings 28, 40, and 49 when valve 10 is in the open position.
Further, the configuration of the valve 10, including the inclusion of block 56 and channels 22, helps prevent cement and/or debris on the outer surface of the outer housing from entering annulus 46 via openings 28 during and after deployment and the cementing operation.
During deployment and cementing, block 56 blocks openings 28 from beneath the cover plates and channels 22 help direct the flow of cement and/or debris away from openings 28. The configuration of valve 10 may therefore assist in isolating the gate from cement and/or debris, which makes the gate less likely to jam or require more actuation force. As discussed above, the outer surface of outer housing 12 may include portions that are raised (i.e. further away from the central long axis than the remaining portions) and such raised portions may allow valve 10 to act as a centralizer for the casing string during deployment. Further, when openings 28 are situated in the raised portions, openings 28 are closer to or are even in contact with the wellbore wall when valve 10 is downhole, thereby minimizing the thickness of the cement sheath to be cracked, which reduces the breakdown pressure required for fracturing. The inclusion of a filler at openings 28 further helps shield the block and the gate from cement and/or debris, and may also help WSLegat,069309 00004',8806813 v3 minimize the thickness of the cement sheath adjacent openings 28. The gasket may further assist in preventing cement and/or debris from entering the valve from the outer surface of the outer housing.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article "a" or "an" is not intended to mean "one and only one" unless specifically so stated, but rather "one or more". All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.
WSLega1\069309 \00004,8806813v3
Background In some wellbore completion operations, a valve is incorporated into a casing string of the well. When the valve is in a closed position, the valve allows cement to flow therethrough inside the casing string. When the valve is in an open position, the valve allows fracturing fluid to flow through the cement casing to fracture the formation near the valve. Using this type of hydraulic frac valve may eliminate the need for perforating the cement casing prior to fracturing.
Commonly used mechanisms for opening the hydraulic frac valve are often at least partially exposed to the flow of cement inside the casing string or in the annulus between the casing string and the wellbore wall. The exposure to cement or other debris can cause the opening mechanism to become jammed thereby rendering the valve inoperable after the cementing process has been completed.
Sumrnary of the Invention In accordance with a broad aspect of the present invention, there is provided a valve having a closed position and an open position, the valve comprising: an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel; a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, and at least one opening; and a gate in an annulus folined between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate blocking fluid communication between the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the closed position, and allowing fluid flow between WSLega1,069309 \00004 \8806813v3 the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the open position.
In accordance with another broad aspect of the present invention, there is provided a method for actuating a valve for treating a subterranean formation, the method comprising: flowing a fluid through the valve, the valve comprising: an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel; a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, at least one opening, and a burst plug in a passageway extending between the outer surface and the inner surface; and a gate in an annulus formed between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate movable axially in the annulus between a first position and a second position; rupturing the burst plug at a selected fluid pressure; flowing fluid through the passageway into the annulus to the gate;
moving the gate from the first position to the second position; exiting fluid through the at least one opening in the at least one opening in the setting sleeve and the at least one opening in the outer housing.
It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Brief Description of the Drawings Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:
Figure 1 is a perspective view of a valve according to one embodiment of the present invention;
WSLega1\069309\00004 \8806813v3 Figure 2 is a side elevation view of the valve; and Figures 3, wherein Figures 3a and 3b are axial cross-sectional views of the valve in a closed position and an open position, respectively.
Detailed Description of Various Embodiments The description that follows and the embodiments described therein are provided by way of illustration of an example, or examples, of particular embodiments of the principles of various aspects of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention in its various aspects. In the description, similar parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features.
Referring to Figures 1 to 3, a valve is shown and a method is described for hydraulically fracturing a wellbore using the valve. A valve 10 of an embodiment of the present invention comprises an outer housing 12, a gate 14, and a setting sleeve 16.
Outer housing 12 is a tubular member having an outer surface and an inner surface defining an inner bore that extends axially from a first end to a second end of the outer housing.
Outer housing 12 may be threaded at both ends, and the threading may form pin or box ends, for connection to the casing string. The casing string is preferably formed to hold pressure. Therefore, any connection should, in the preferred embodiment, be selected to be substantially pressure tight. Preferably, the casing string is resistant to fluid flow outwardly therefrom except through (i) open ports in valve 10 when in an open position and (ii) its lower end when it is open.
In one embodiment, outer housing 12 has two parts: a top sub 18 and a bottom sub 20, both of which are tubular members each having an outer surface and an inner surface defining an axially extending inner bore. A second end of the top sub is coupled to a first end of the bottom sub and the two subs may be connected in various ways. For example, the second end of the top sub is internally threaded and the first end of the bottom sub is WSLega1\069309 \00004 \8806813v3 externally threaded, such that the two ends can be threadedly connected to each other to form outer housing 12. A first end of the top sub and a second end of the bottom sub are the first and second ends of the outer housing, respectively, and each may be threaded to form pin or box ends for connection to the casing string. The inner and/or outer surfaces of the top and bottom subs may include annular grooves 21 for receiving suitable annular seals, such as o-rings, for fluidly sealing an interface between two surfaces.
A recess is provided on the inner surface of the bottom sub for accommodating a snap ring 23.
The outer surface of the outer housing 12 includes at least one channel 22 for helping to direct and/or facilitate the flow of fluid therethrough along the outer surface of the outer housing, when valve 10 is in use. In one embodiment, the channel is an indentation on the outer surface of the outer housing, including for example a slot and/or groove. In another embodiment, the channel is formed between at least two radially outwardly projecting portions and/or members on the outer surface of the outer housing. For example, the outer surface of the outer housing may include a plurality of ridges that define a plurality of channels therebetween. The channel has a base, which is a surface that is indented compared to surrounding surfaces. In other words, the base is closer to the central long axis of the outer housing than the other surfaces around adjacent to the base.
The channel may be linear in shape and may be formed to extend lengthwise on the outer surface of the outer housing. In a further embodiment, the channel may be formed to be substantially parallel to the long axis of the inner bore of the outer housing. In another embodiment, a portion of the channel may be curved, C-shaped, S-shaped, etc.
Further, the depth of the channel, which is defined by the minimum distance between the base and an adjacent radially outwardly-facing surface, may be substantially uniform or may vary along the length of the channel. In addition to its shape, the length, width, and depth of the channel may vary depending on the characteristics of the fluid to flow therethrough and/or the overall dimensions of the outer housing. The number of channels formed on the outer surface of the outer housing may vary and may depend on the configuration of the other components of the valve 10, which are described in detail hereinbelow. In one embodiment, six channels are provided on the outer surface of the outer housing wherein the channels are substantially equidistance apart around the outer circumference of the outer housing.
WSLegal\ 069309 \00004'.8806813v3 Outer housing 12 has at least one opening 24 that allows fluid communication between its inner and outer surfaces. In one embodiment, the opening is positioned between two adjacent channels on the outer surface of the outer housing. In a further embodiment, the opening is formed in a portion of the outer surface that is furthest away from the central long axis of the outer housing. In other words, the base of the at least one channel is closer to the long axis than the portion where the at least one opening is positioned. In one embodiment, outer housing 12 has a plurality of openings 24 forming a single row around the circumference of the outer housing. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 24. Of course, the number, spacing, and distribution of openings 24 in outer housing 12 may vary.
The inner surface of outer housing 12 may include a shoulder 25, between the edge of opening 24 that is closest to the second end of the outer housing and the second end of the outer housing.
In the illustrated embodiment, a portion of the opening is covered with a cover plate 26.
Cover plate 26 has an opening 28 and is attachable to the outer housing in various ways, including for example by fasteners, mechanical engagement between the cover plate and the outer housing, adhesives, bonding, welding, etc. or a combination thereof.
In one embodiment, cover plate 26 is substantially rectangular and has substantially planar outer and inner surfaces. The shape of cover plate 26 may vary and may depend on the shape of the opening 24 in the outer housing.
In a further embodiment, cover plate 26 includes holes near its ends and outer housing 12 includes holes 30 above the opening 24 and holes 32 below opening 24, such that holes are closer to top sub 18 than holes 32. Cover plate 26 may be secured to the outer housing by placing plate 26 over opening 24, aligning the holes in the cover plate and 25 holes 30, 32, and fastening fasteners 33, 34 through the aligned holes above and below opening 24, respectively. The inner surface of cover plate 26 directly faces opening 24 when plate 26 is attached to outer housing 12. In a further embodiment, fasteners 33, 34 are selected such that when they are fastened in both the holes in the cover plate and holes 30, 32, the tops of the fasteners are substantially flush with or slightly recessed 30 from the outer surface of cover plate 26.
WSLega1\069309 \00004 ',8806813v3 In one embodiment, the outer housing and cover plate are configured to mechanically engage one another. For example, the outer housing may include dovetail grooves at the side edges of opening 24 into which the side edges of cover plate 26 can slide, thereby further securing the cover plate in place over opening 24.
In another embodiment, part of the outer surface of outer housing 12 near opening 24 is recessed for receiving the edges of cover plate 26. The recess may have a depth that is substantially the same as the thickness of cover plate 26, such that when cover plate 26 is received in the recess, the outer surface of cover plate 26 is substantially flush with the non-recessed outer surface of outer housing 12.
Cover plate 26 further includes an aperture 36 for receiving a shear screw 38 therein.
In one embodiment, cover plate 26 is made of high impact strength material, including for example 4140 110K MYS alloy steel.
In one embodiment, outer housing 12 has a plurality of openings 24 and cover plates 26 are installed thereon to cover a portion of each of the openings, such that openings 28 forms a single row around the circumference of the outer housing. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 28. Of course, the number, spacing, and distribution of openings 28 on outer housing 12 may vary.
In another embodiment, the outer housing is configured such that the addition of a cover plate is not necessary. For example, opening 24 in the outer housing may be sized and positioned in a similar manner as opening 28, as described herein, such that opening 24 can function substantially the same as opening 28, thereby rendering cover plate 26 unnecessary.
Setting sleeve 16 is a tubular member having an outer surface and an inner surface defining an inner bore that extends axially from a first end to a second end of the setting sleeve. The setting sleeve extends axially in the inner bore of the outer housing, between the first end of the top sub and the second end of the bottom sub, such that fluid can flow WSLegat,069309',00004' 8806813v3 between the first and second ends of the outer housing via the inner bore of the setting sleeve. Setting sleeve 16 may share the same central long axis as outer housing 12.
Setting sleeve 16 has at least one opening 40 that allows fluid communication between its inner and outer surfaces. In one embodiment, setting sleeve 16 has a plurality of openings 40 forming a single row around the circumference of the setting sleeve. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 40. Of course, the number, spacing, and distribution of openings 40 in setting sleeve 16 may vary.
The outer surface of setting sleeve 16 may include a shoulder 43. Setting sleeve 16 also includes a burst plug 41 (sometimes also referred to as a rupture disc, bursting disc, or burst diaphragm) positioned in a passageway extending between the inner and outer surfaces of the setting sleeve. When intact, burst plug 41 restricts fluid communication between the inner and outer surface of the setting sleeve via the passageway.
Once burst plug 41 is ruptured, the passageway opens up, allowing fluid to flow between the inner and outer surfaces of the setting sleeve. The setting sleeve may be configured such that the passageway (and therefore the burst plug) is situated near one end thereof.
In one embodiment, the inner surface of outer housing 12 includes shoulders 42 and 44 near the first end of the top sub and the second end of the bottom sub, respectively.
Shoulders 42, 44 can be formed in any way as by casting, milling, etc. the wall material of the outer housing or by threading parts together. Setting sleeve 16 is contained inside the outer housing, between the first end of the top sub and the second end of the bottom sub, by engaging the shoulders 42 and 44. The outer surface of setting sleeve 16 may optionally have a threaded portion at the first end for connecting to a threaded portion on the inner surface of the top sub, thereby securing the setting sleeve inside the outer housing. A portion of the outer surface of the setting sleeve and a portion of the inner surface of the outer housing are spaced apart to define an annulus 46.
In a further embodiment, holes 32 extend from the outer surface of outer housing 12 to adjacent the outer surface of setting sleeve 16 and the outer surface of setting sleeve 16 includes indentations that are aligned with holes 32 for receiving the feet of fasteners 34.
WSLega1\069309,00004\8806813v3 When fasteners 34 are fastened through the holes in the cover plate and holes 32, their feet extend into and engage the indentations in the outer surface of setting sleeve 16, thereby securing setting sleeve 16 to the outer housing 12, which helps prevent setting sleeve 16 from rotating relative to the outer housing and assists in aligning the holes in the cover plate, the gate, and the setting sleeve when valve 10 is in the open position, as described in more detail hereinbelow.
The gate 14 is provided in the annulus 46. The gate is a tubular member having an outer surface and an inner surface defining an inner bore that extends axially from a first end to a second end of the gate. The length of gate 14 is shorter than the length of annulus 46 such that gate 14 is slideable axially within annulus 46 between a first position and a second position. In the first position, gate 14 is closer to the first end of the top sub than in the second position. Gate 14 has at least one opening 49 that allows fluid communication between its inner and outer surfaces. In one embodiment, gate 14 has a plurality of openings 49 forming a single row around the circumference of the gate. In a further embodiment, the single row includes six substantially evenly radially spaced-apart openings 49. Of course, the number, spacing, and distribution of openings 49 in gate 14 may vary. The inner and outer surfaces of gate 14 may include annular recesses 50 for receiving suitable seals, such as o-rings, so that fluid bypass between the gate and the setting sleeve and outer housing is substantially prevented. The outer surface of gate 14 includes an annular groove 52 for receiving the snap ring 23. Gate 14 further includes a block 56, which is a raised surface or a radially outwardly projecting member on the outer surface for engaging with the inner surface of cover plates 26 or outer housing 12.
Block 56 may be a single ring-shaped component or one or more spaced-apart platforms.
Block 56 may be a separate component that is attached to the outer surface of gate 14 or formed with the gate 14 as a single part during manufacturing. In one embodiment, the interface between the gate 14 and block 56 includes a tongue and groove joint 60 to provide mechanical engagement between the two parts. There are of course many ways to attach block 56 to the outer surface of gate 14, including for example by fasteners, adhesives, bonding, welding, friction fitting, etc. Recesses are provided on the outer surface of block 56 for receiving a portion of the shear screws 38.
WSLegaH)69309\00004..8806813v3 A breakable filler may optionally be provided at openings 28 of cover plates 26 to substantially shield block 56 from the space adjacent the outer surface of cover plates.
The filler may be disposed adjacent to the outer surface of the block. The filler may be made of plastic and/or a composite solid. Additionally or alternatively, a solid or gel-type gasket may be provided for substantially sealing the cover plates against the block and outer housing. The gasket may be made of silicone or a composite material. The material of both the filler and the gasket is selected so that it breaks and disintegrates when it is exposed to fluids at and above a certain fluid pressure and/or flow rate (e.g.
fluid pressure and/or flow rate of the fracing fluid during the fi-acing process).
The components of valve 10 may be constructed of any suitable material, such as plastic, aluminum, steel, ceramic, and so on, with consideration as to the conditions in which they must operate.
Valve 10 is transitionable from a closed position to an open position. In the closed position, burst plug 41 in setting sleeve 16 is intact and gate 14 is in the first position, wherein the gate is positioned in a portion of the annulus that is closer to the first end of the outer housing, and wherein openings 49 are sandwiched in between the inner surface of the outer housing and the outer surface of setting sleeve 16 and are not in communication with openings 40 and openings 28, such that no fluid can flow through openings 49. When gate 14 is in the first position, block 56 blocks openings 24, or openings 28 if cover plates 26 are used. In one embodiment, cover plates 26 are used and, when the gate is in the first position, block 56 engages the inner surface of cover plates 26 and blocks openings 28. Also, in the first position, openings 40 are blocked by a portion of the inner surface of the gate 14. Therefore, in the closed position, gate 14 provides a fluid barrier between openings 40 and openings 28 (or openings 24 if no cover plates are used), such that no fluid can flow between the outer surface of the outer housing 12 and the inner bore of setting sleeve 16 via openings 40. In the closed position, block 56 is attached to cover plates 26 (or outer housing 12 if cover plates are omitted) by shear screws 38, which helps maintain the gate in the first position before the valve 10 is actuated. The first end of the gate 14 may abut against shoulder 43 when the gate is in the first position. Shoulder 43 helps prevent gate 14 from sliding beyond a certain point in WSLegal \ 069309 \ 00004%8068130 ¨ 10 -the annulus towards the first end of the outer housing. Seals are provided in annular recesses 50 such that the interface between the gate and each of the outer housing and the setting sleeve is fluidly sealed. In the closed position, the annulus is fluidly isolated from the inner bore of the setting sleeve and the outer surface of the outer housing. In addition, the space in the annulus adjacent to the first end of the gate and the space in the annulus adjacent to the second end of the gate are fluidly sealed from each other.
In the open position, burst plug 41 in setting sleeve 16 is ruptured, shear screws 38 are sheared, and gate 14 is in the second position, wherein the gate is positioned in a portion of the annulus that is closer to the second end of the outer housing, and wherein openings 49 are in communication with openings 40 and openings 24 (or openings 28 if cover plates 26 are used), such that fluid can flow between the inner bore of the setting sleeve and the outer surface of the outer housing through all three openings 28, 40, and 49. In one embodiment, the openings 28, 40, and 49 are substantially aligned when the valve is in the open position. While in the illustrated embodiment, openings 28, 40 and 49 are shown to be similarly shaped and sized, it can be appreciated that the size and shape of openings 28, 40 and 49 may be different from one another. With the burst plug ruptured, the space in the annulus adjacent to the first end of the gate is in fluid communication with the inner bore of the setting sleeve. In the open position, shear screws 38 are sheared so that block 56 is no longer attached to cover plates 26 (or outer housing 12 if cover plates are omitted), which allows the gate to move to the second position after the valve 10 is actuated. When gate 14 is in the second position, block 56 is shifted towards the second end of the outer housing, thereby unblocking openings 24, or openings 28 if cover plates 26 are used. In one embodiment where cover plates 26 are used, block 56 is shifted to engage a portion of the inner surface of cover plates 26 that does not contain openings 28. Also, in the second position, openings 49 in gate 14 are shifted towards the second end of the outer housing to be in communication with openings 40 and 28 (or openings 24 if no cover plates are used). Therefore, in the open position, the position of gate 14 allows fluid to flow between the outer surface of the outer housing 12 and the inner bore of setting sleeve 16 via the openings 28, 40, and 49. In the open position, a portion of snap ring 23 is snapped into groove 52 to help maintain the gate in the second position.
The second end of the gate may be beveled to assist in opening up snap ring 23 and to WSLegah069309 \00004 \88068130 =
¨ 11 -facilitate the sliding of snap ring 23 on to the outer surface of the gate towards groove 52.
The second end of the gate 14 may abut against shoulder 25 when the gate is in the second position. Shoulder 25 helps prevent gate 14 from sliding beyond a certain point in the annulus towards the second end of the outer housing.
In use, valve 10 may be connected to the casing string by the first and second ends of the outer housing. One or more valves may be incorporated into the casing string.
In one embodiment, when the casing string is downhole, the first end of the outer housing is the upper end and the second end being the lower end, with the upper end being closer to the wellbore opening at surface than the lower end. In an alternative embodiment, valve 10 can still operate when installed into the casing string "upside down," wherein when the casing string is downhole, the second end of the outer housing is the upper end and the first end of the outer housing is the lower end.
Before deployment into the wellbore, valve 10 is in the closed position, wherein the flow path between openings 28 and 40 is blocked by block 56. After the casing string along with valve 10 is deployed in the wellbore, cement is pumped down inside the casing string and out the lower end of the casing string into the annulus between the wellbore wall and the outer surface of the casing, a procedure which is known to those skilled in the art. After the cement flow is terminated, a wiper plug or other device is pumped down to wipe the inner bore wall of the casing and valve substantially clean of residual cement.
When the wiper plug or other device has latched or sealed in the bottom hole assembly, fracturing fluid is pumped down the through coiled tubing (and/or the coiled tubing is rotated) to set a straddle packer attached to the coiled tubing at either end of the valve to seal off the valve. The straddle packer isolates the fracture fluid inside the inner bore of the valve. As fracturing fluid is continuously pumped into the coiled tubing, fluid pressure inside the isolated inner bore of the valve is increased to rupture burst plug 41 at a predetermined pressure, thereby actuating the valve.
After burst plug 41 is ruptured, fracturing fluid inside the casing string and therefore the inner bore of setting sleeve 16 flows into the space adjacent the first end of gate 14 inside annulus 46. As more fluid flows into annulus 46 near the first end of the gate, the WSLegal\ 069309 \00004 \8806813v3 increase in fluid pressure exerts a force on the gate in the direction opposite the burst plug 41, for example in the direction of the lower end of the outer housing as shown in the illustrated embodiment (or in the direction of the upper end if the valve is installed upside down). When the force on the gate reaches a predetermined threshold, the shear screws 38 are broken, which slides the gate axially in annulus 46. While the gate slides toward the lower end, any air or fluid in the space adjacent the second end of the gate in annulus 46 can escape via openings 28. When the second end of the gate encounters snap ring 23, the snap ring is urged by the gate to expand and slide on to the outer surface of the gate.
Once the snap ring snaps on to groove 52, the valve 10 is in the open position, wherein the flow path between openings 28 and 40 is unblocked, and openings 28 and 40 are in fluid communication via openings 49. In the open position, fracturing fluid is allowed to exit the valve via the openings 28, 40, and 49, in order to crack the cement sheath and fracture the formation adjacent to the outer surface of the valve near openings 28.
As described above, valve 10 may be configured to have screws 34 extend into and engage indentations in the outer surface of setting sleeve 16 to assist in maintaining the alignment of openings 28, 40, and 49 when valve 10 is in the open position.
Further, the configuration of the valve 10, including the inclusion of block 56 and channels 22, helps prevent cement and/or debris on the outer surface of the outer housing from entering annulus 46 via openings 28 during and after deployment and the cementing operation.
During deployment and cementing, block 56 blocks openings 28 from beneath the cover plates and channels 22 help direct the flow of cement and/or debris away from openings 28. The configuration of valve 10 may therefore assist in isolating the gate from cement and/or debris, which makes the gate less likely to jam or require more actuation force. As discussed above, the outer surface of outer housing 12 may include portions that are raised (i.e. further away from the central long axis than the remaining portions) and such raised portions may allow valve 10 to act as a centralizer for the casing string during deployment. Further, when openings 28 are situated in the raised portions, openings 28 are closer to or are even in contact with the wellbore wall when valve 10 is downhole, thereby minimizing the thickness of the cement sheath to be cracked, which reduces the breakdown pressure required for fracturing. The inclusion of a filler at openings 28 further helps shield the block and the gate from cement and/or debris, and may also help WSLegat,069309 00004',8806813 v3 minimize the thickness of the cement sheath adjacent openings 28. The gasket may further assist in preventing cement and/or debris from entering the valve from the outer surface of the outer housing.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article "a" or "an" is not intended to mean "one and only one" unless specifically so stated, but rather "one or more". All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.
WSLega1\069309 \00004,8806813v3
Claims (27)
1. A valve having a closed position and an open position, the valve comprising:
an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel;
a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, and at least one opening; and a gate in an annulus formed between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate blocking fluid communication between the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the closed position, and allowing fluid flow between the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the open position.
an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel;
a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, and at least one opening; and a gate in an annulus formed between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate blocking fluid communication between the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the closed position, and allowing fluid flow between the at least one opening in the outer housing and the at least one opening in the setting sleeve when the valve is in the open position.
2. The valve of claim 1 wherein the at least one opening in the outer housing is positioned in a portion of the outer surface that is further away from a central long axis of the outer housing than the remaining portion of the outer surface.
3. The valve of claim 2 wherein the at least one channel is positioned in the remaining portion of the outer surface.
4. The valve of claim 1 further comprising at least one cover plate having an opening and wherein the at least one cover plate covers a portion of the at least one opening in the outer housing.
5. The valve of claim 4 wherein the at least one opening in the at least one cover plate is positioned in a portion of the outer surface that is further away from a central long axis of the outer housing than the remaining portion of the outer surface
6. The valve of claim 1 further comprising at least one burst plug in a passageway extending between the inner and outer surfaces of the setting sleeve.
7. The valve of claim 1 further cornprising a snap ring on the inner surface of the outer housing, and a groove on the outer surface of the gate for receiving a portion of the snap ring.
8. The valve of claim 1 wherein the first and second ends are configured for connection to tubing for use in a wellbore.
9. The valve of claim 1 wherein the gate is slideable between a first position and a second position in the annulus, and wherein the gate is in the first position when the valve is in the closed position and in the second position when the valve is in the open position.
10. The valve of claims 6 and 9 wherein the gate is closer to the burst plug when in the first position than the second position.
11. The valve of claim 4 wherein the gate includes a block for blocking the opening in the at least one cover plate when the valve in the closed position.
12. The valve of claim 1 further comprising a filler disposed in the at least one opening of the outer housing.
13. The valve of claim 4 further comprising a gasket for substantially sealing the cover plate against the gate and the outer housing.
14. A method for actuating a valve for treating a subterranean formation, the method cornprising:
flowing a fluid through the valve, the valve comprising: an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel; a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, at least one opening, and a burst plug in a passageway extending between the outer surface and the inner surface; and a gate in an annulus formed between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate movable axially in the annulus between a first position and a second position;
rupturing the burst plug at a selected fluid pressure;
flowing fluid through the passageway into the annulus to the gate;
moving the gate from the first position to the second position;
exiting fluid through the at least one opening in the at least one opening in the setting sleeve and the at least one opening in the outer housing.
flowing a fluid through the valve, the valve comprising: an outer housing having an outer surface, an inner surface, a first end, a second end, and at least one opening, the outer surface having at least one channel; a setting sleeve positioned within the outer housing, the setting sleeve having an outer surface, an inner surface, at least one opening, and a burst plug in a passageway extending between the outer surface and the inner surface; and a gate in an annulus formed between the inner surface of the outer housing and the outer surface of the setting sleeve, the gate movable axially in the annulus between a first position and a second position;
rupturing the burst plug at a selected fluid pressure;
flowing fluid through the passageway into the annulus to the gate;
moving the gate from the first position to the second position;
exiting fluid through the at least one opening in the at least one opening in the setting sleeve and the at least one opening in the outer housing.
15. The method of claim 14 wherein the at least one opening in the outer housing is positioned in a portion of the outer surface that is further away from a central long axis of the outer housing than the remaining portion of the outer surface.
16. The method of claim 15 wherein the at least one channel is positioned in the remaining portion of the outer surface.
17. The method of claim 14 wherein the valve further comprises at least one cover plate having an opening and wherein the at least one cover plate covers a portion of the at least one opening in the outer housing.
18. The method of claim 17 wherein the at least one opening in the at least one cover plate is positioned in a portion of the outer surface that is further away from a central long axis of the outer housing than the remaining portion of the outer surface.
19. The method of claim 14 where in the valve further comprises a snap ring on the inner surface of the outer housing, and a groove on the outer surface of the gate for receiving a portion of the snap ring.
20. The method of claim 14 wherein the gate is closer to the burst plug when in the first position than the second position.
21. The method of claim 17 wherein the gate includes a block, the block blocking the opening in the at least one cover plate when the gate is in the first position.
22. The method of claim 14 further comprising connecting the valve to a casing string.
23. The method of claim 14 further comprising pumping cement through the valve into a wellbore.
24. The method of claim 14 further comprising wiping the valve with a wiper plug.
25. The method of claim 14 further comprising engaging the gate with the outer housing when the gate is in the first position and in the second position.
26. The valve of claim 14 wherein the valve further comprises a filler disposed in the at least one opening of the outer housing.
27. The valve of claim 17 wherein the valve further comprises a gasket for substantially sealing the cover plate against the gate and the outer housing.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA2820283A CA2820283A1 (en) | 2013-06-19 | 2013-06-19 | Valve and method for hydraulic fracturing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA2820283A CA2820283A1 (en) | 2013-06-19 | 2013-06-19 | Valve and method for hydraulic fracturing |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2820283A1 true CA2820283A1 (en) | 2014-12-19 |
Family
ID=52105645
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA2820283A Abandoned CA2820283A1 (en) | 2013-06-19 | 2013-06-19 | Valve and method for hydraulic fracturing |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA2820283A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106246137A (en) * | 2016-08-02 | 2016-12-21 | 中国海洋石油总公司 | A kind of magnetic force storm valve |
CN109505535A (en) * | 2017-09-15 | 2019-03-22 | 中国石油天然气股份有限公司 | A kind of tubing string |
CN111894543A (en) * | 2020-07-16 | 2020-11-06 | 中国石油天然气股份有限公司 | Liquid carbon dioxide anhydrous fracturing normal-pressure sand adding method and device |
-
2013
- 2013-06-19 CA CA2820283A patent/CA2820283A1/en not_active Abandoned
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106246137A (en) * | 2016-08-02 | 2016-12-21 | 中国海洋石油总公司 | A kind of magnetic force storm valve |
CN109505535A (en) * | 2017-09-15 | 2019-03-22 | 中国石油天然气股份有限公司 | A kind of tubing string |
CN111894543A (en) * | 2020-07-16 | 2020-11-06 | 中国石油天然气股份有限公司 | Liquid carbon dioxide anhydrous fracturing normal-pressure sand adding method and device |
CN111894543B (en) * | 2020-07-16 | 2023-04-25 | 中国石油天然气股份有限公司 | Liquid carbon dioxide anhydrous fracturing normal-pressure sand adding method and device |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
FZDE | Discontinued |
Effective date: 20170620 |