United States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,449,039
`
`Hartley et a1.
`
`[45] Date of Patent:
`
`Sep. 12, 1995
`
`IlllllllllllllllllllllIllllllllllllllllllllllllllllllllllllllllllllllllllll
`USOO5449039A
`
`7/1929 Regalbuto ........................ .. 175/4.56
`4,350,432
`5,033,557 2/1992 Riclesetal.
`166/297
`5,107,927 4/1992 Whiteley et al.
`.. 166/50
`5,224,556
`7/1993 Wilson etal. .................... .. 175/453
`
`
`
`APPARATUS AND METHOD FOR
`HORIZONTAL WELL FRACTURE
`STIMULATION
`
`Inventors: Alan C. Hartley, Rocky Rapids;
`Russell S. J. Krasey, Calgary, both of
`Canada
`
`Primary Examiner—Hoang G. Dang
`Attorney, Agent, or Fz'rm——John Wade Carpenter
`
`[54]
`
`[75]
`
`[73]
`
`[21]
`
`[22]
`
`[51]
`[52]
`
`[531
`
`[561
`
`Assignee: Canadian Occidental Petroleum, Ltd.,
`Calgary, Canada
`
`Appl. No.: 192,379
`
`Filed:
`
`Feb. 7, 1994
`
`Int. Cl.5 ...................... E21B 43/117; E21B 43/12
`U.S. Cl. .................................... .. 166/297; 166/50;
`166/55.1; 175/4.56
`Field of Search ........................ 166/297, 55.1, 50;
`175/4.56
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`2,866,508 12/1958 Church .......................... 175/4.56 X
`3,240,273
`3/1966 Solari et a1.
`.
`3,468,386 9/1969 Johnson ........................ .. 166/100 X
`4,299,287 11/1981 Varm et a1
`166/297
`4,484,632 ll/1984 Vann ... .. .... ..
`. .... 166/297
`4,512,406 4/1985 Vann et al
`166/297
`4,515,217
`5/1985 Stout ..
`. 166/297
`4,544,034 10/1985 George
`. 166/297
`4,554,981 11/1985 Davies
`66/55.1 X
`4,619,333 10/1986
`175/4.52
`4,637,478
`1/1987
`
`
`
`ABSTRACI‘
`[57]
`An apparatus and method for perforating in deviated
`and horizontal wells. A firing pin and charge housing is
`integrally secured to a generally tubular body. The
`firing pin and charge housing has a structure defining at
`least one recess extending through the firing pin and
`charge housing and communicating with at least one
`tubular bore within the tubular body. The recess co1n~
`prises at least one charge recess communicating with
`the at least one tubular bore. A firing pin is biasingly
`disposed in the recess and an explosive member is dis-
`posed in the charge recess. A detonator is positioned in
`the recess and is engaged to the explosive member for
`detonating the latter. A sleeve member is slidably dis-
`posed in the tubular bore and has at least one sleeve
`opening and a shear pin bound thereto and extending
`through the recess for engaging the firing pin. The
`sleeve member includes a sleeve seat for receiving a
`plug to slidably move the sleeve member and cause the
`shear pin to shear and to align the sleeve opening with
`the charge recess and cause the firing pin to contact the
`detonator and discharge the explosive member.
`
`22 Claims, 8 Drawing Sheets
`
`
`
`
`
`.-=\\V\_\;x\‘.e‘..\\\s 1‘
`
`
`BAKER HUGHES INCORPORATED
`
`
`
`Exhibit 1003
`
`Page 1 of 15
`
`

`
`U.S. Patent
`
`Sep. 12, 1995
`
`Sheet 1 of 8
`
`5,449,039
`
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`
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`Page 2 0f15
`
`
`
`

`
`U.S. Patent
`
`Sep. 12, 1995
`
`Sheet 2 of s
`
`5,449,039
`
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`Page 3 of 15
`
`
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`

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`U.S. Patent
`
`S
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`11
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`Page 4 of15
`
`
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`

`
`U.S. Patent
`
`Sep. 12,1995
`
`Sheet 4 of 8
`
`5,449,039
`
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`

`
`U.S. Patent
`
`Sep. 12, 1995
`
`Sheet 5 of 3
`
`5,449,039
`
`Page 6 0f15
`
`

`
`U.S. Patent
`
`Sep. 12, 1995
`
`Sheet 6 of 8
`
`5,449,039
`
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`
`U.S. Patent
`
`Sep. 12, 1995
`
`Sheet 7 of 8
`
`5,449,039
`
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`

`
`U.S. Patent
`
`Sep. 12, 1995
`
`Sheet 8 of 8
`
`5,449,039
`
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`
`Page 9 0f15
`
`

`
`1
`
`5,449,039
`
`2
`
`APPARATUS AND METHOD FOR HORIZONTAL
`WELL FRACTURE STIMULATION
`
`FIELD OF THE INVENTION
`
`The present invention is related to a tool and method
`for perforating a well to allow for fracture stimulations.
`More specifically, the present invention provides an
`apparatus and method for allowing multiple low cost
`fracture stimulations to be performed in cemented hori-
`zontal wells.
`
`10
`
`DESCRIPTION OF THE PRIOR ART
`
`15
`
`In the course of completing an oil and/or gas well, it
`is common practice to run a string of casing into the
`well and then cement the casing in place. The casing is
`subsequently perforated at the pay zone of the reservoir
`by the use of coiled tubing disposing a casing perforat-
`ing gun at the desired location within the casing. The
`casing gun is retrieved and the well may be subse-
`quently stimulated in a conventional manner. After
`clean-up a bridge plug or packer is set uphole from the
`initial fracture stimulation, and the process is repeated
`for every fracture stimulation subsequently performed.
`Example of wireline or cable conveyed perforating
`guns or actuator devices or stimulating devices are
`disclosed in the following U.S. Patents: U.S. Pat. No.
`3,240,273 to Solari et al entitled “METHOD AND
`APPARATUS FOR WELL STIMULATION”; U.S.
`Pat. No. 4,299,287 to Vann et al entitled “BAR ACTI-
`VATED VENT ASSEMBLY AND PERFORAT-
`ING GUN”; U.S. Pat. No. 4,512,406 to Vann et al
`entitled “BAR ACTUATED VENT ASSEMBLY”;
`U.S. Pat. No. 4,544,034 to George entitled “ACTUA-
`TION OF A GUN FIRING HEAD”; U.S. Pat. No.
`4,619,333 to George entitled “DETONATION OF
`TANDEM GUNS”; U.S. Pat. No. 4,637,478 to George
`entitled “GRAVITY ORIENTED PERFORATING
`GUN FOR USE IN SLANTED BOREHOLES”; U.S.
`Pat. No. 4,850,438 to Regalbuto entitled “MODULAR
`PERFORATING GUN”; U.S. Pat. No. 5,088,557 to
`Ricles entitled “DOWNHOLE PRESSURE ATTEN-
`UATION APPARATUS”; and U.S. Pat. No. 5,107,927
`to Whiteley et al entitled “ORIENTING TOOL FOR
`SLANT/HORIZONTAL COMPLETIONS”.
`The disadvantages of conventional apparatuses and
`methods which are currently being employed in com-
`mercial operations today are the cost to do the work
`and the time required to complete multiple fracture
`stimulations. Each individual fracture stimulation may
`take up to three days to complete. Therefore, what is
`needed and what has been invented by us is an appara-
`tus and method for reducing the time for completing
`each selective fracture stimulation to a single day or
`less. Also what is needed and what has been invented by
`us is an apparatus and method that will eliminate the
`need for coiled tubing conveyed perforating since the
`perforating charges are part of the apparatus itself. Our
`invention will also eliminate the need for the setting of
`bridge plugs or packers for isolating horizontal sections
`because the setting of plugs in the tool or apparatus
`itself makes for or accomplishes effective horizontal
`section isolation. Our invention will allow for cheaper
`and more efficient stimulation of cemented wells, espe-
`cially horizontal cemented well.
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`SUMMARY OF THE INVENTION
`
`The present invention accomplishes its desired object
`by broadly providing an apparatus which connects to
`casing and perforates the cement of wells, especially
`deviated and horizontal wells. The apparatus has a gen-
`erally tubular body comprising a first tubular bore with
`a first internal diameter and a second tubular bore with
`a second internal diameter that is less than the first
`internal diameter. A firing pin and charge housing is
`integrally secured to or formed with the generally tubu-
`lar body. The firing pin and charge housing has a struc-
`ture defining a firing pin recess, a slot extending be-
`tween the firing pin recess and the second tubular bore
`such that said firing pin recess is capable of communi-
`cating with the second tubular bore, and at least one
`charge recess extending through the firing pin and
`charge housing and communicating with the second
`tubular bore. The firing pin and charge housing also has
`a detonator bore extending from the firing pin recess to
`the charge recess. A firing pin is biasingly disposed in
`the firing pin recess; and an explosive member is dis-
`posed in the charge recess. In order to detonate the
`explosive member a detonator is disposed in the detona-
`tor bore and is engaged to the explosive member. A
`sleeve member slidably is provided as being disposed in
`the second tubular bore and having at least one sleeve
`opening and a shear pin bound thereto and extending
`through the slot and releasably engaged to the firing
`pin. The sleeve member comprises a sleeve seat means
`for receiving a plug to slidably move the sleeve member
`and cause the shear pin to shear for aligning the sleeve
`opening with the charge recess and cause the firing pin
`to contact the detonator and discharge the explosive
`member.
`The present invention also accomplishes its desired
`objects by further broadly providing a method for stim-
`ulating a hydrocarbon reservoir in a horizontal well
`bore comprising the steps of initially providing a tool
`having a sleeve member including a sleeve seat means
`for receiving a plug; and subsequently securing casing
`to the tool. The casing with the tool attached thereto is
`run into a horizontal well bore. The casing is cemented
`in place in accordance with conventional procedures. A
`plug that has been dimensioned to seat in the sleeve seat
`means is provided, and the plug is dispersed in the cas-
`ing and pumped through the casing until the plug en-
`counters the sleeve seat means. The plug is presssurized
`to cause at least one first pin means within the tool to
`sever. The method also comprises severing a second pin
`within the tool to cause and allow the sleeve member to
`slide within the tool; perforating the cement surround-
`ing the tool; and stimulating a hydrocarbon reservoir
`through which the horizontal well bore passes.
`The method of the present invention may further
`comprise securing a second tool to the casing wherein
`the second tool has a second sleeve seat means that is
`larger than the sleeve seat means of the first tool; and
`providing a second plug that is larger than the plug for
`the first tool. The method also further comprises pump-
`ing the second plug through the casing until the second
`plug encounters the second sleeve seat means; pressuriz-
`ing the second plug to cause at least one second pin
`means within the second tool to sever; severing a sec-
`ond pin within the second tool to cause and allow a
`second sleeve member to slide within the second tool;
`perforating cement surrounding the second tool; and
`
`Page 10 of 15
`
`

`
`3
`stimulating the hydrocarbon reservoir through the sec-
`ond tool.
`It is therefore an object of the present invention to
`provide an apparatus or tool for allowing low cost frac-
`ture stimulations to be performed in wells, particularly
`cemented horizontal wells.
`It is another object of the present invention to pro-
`vide a method for allowing multiple low cost fracture
`stimulations to be performed in cemented horizontal
`wells.
`These, together with the various ancillary objects
`and features which will become apparent
`to those
`skilled in the art as the following description proceeds,
`are attained by this invention, a preferred embodiment
`as shown with reference to the accompanying draw-
`ings, by way of example only, wherein;
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a schematic diagram of five (5) apparatuses
`or tools of the present invention interconnecting or
`coupling of easing together for a horizontal completion,
`with two of the tools having been activated and fractur-
`ing of the reservoir completed at the location of the
`tools, with one tool in an active position and postured
`for fracturing of the reservoir, and with the remaining
`two tools being in a passive position;
`FIG. 2 is a schematic diagram of a tool interconnect-
`ing or coupling casing and in a passive position;
`FIG. 3 is a schematic diagram of the tool in FIG. 2
`after being activated;
`FIG. 4 is a partial side elevational, vertical sectional,
`segmented view of the tool of the present invention;
`FIG. 5 is a partial vertical sectional and segmented
`View of the tool of the present invention;
`FIG. 6 is a horizontal sectional view of the tool of the
`present invention taken in direction of the arrows and
`along the plane of line 6——6 in FIG. 5;
`FIG. 7 is a horizontal sectional view of the tool of the
`present invention taken in direction of the arrows and
`along the plane of line 7--7 in FIG. 5;
`FIG. 8 is a horizontal sectional view of the tool of the
`present invention taken in direction of the arrows and
`along the plane of line 8—8 in FIG. 5;
`FIG. 9 is a partial vertical, segmented view of the
`tool of the present invention immediately after a plug
`has moved the sleeve and released the firing pin to
`contact the detonator and immediately, instantaneously
`before the charges or explosives are to explode and
`perforate the cement;
`FIG. 10 is a partial vertical, segmented View of the
`tool of the present invention immediately after a plug
`has moved the sleeve and released the firing pin to
`contact the detonator which has exploded or set-off the
`charges or explosives that have perforated the cement;
`and
`FIG. 11 is a partial and segmented sectional view of
`a horizontal completion with two of the tools of the
`present invention, one being downhole and one being
`uphole with the downhole tool having a smaller internal
`diameter landing nipple than the uphole tool.
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`l0
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`Referring in detail now to the drawings wherein
`similar parts of the invention are identified by like refer-
`ence numerals, there is seen the apparatus or tool gener-
`ally illustrated as 10 (see FIGS. 4 and 5). The tool 10 has
`a passive position, which is generally illustrated as 12,
`
`65
`
`5,449,039
`
`4
`and an active position which is generally illustrated as
`14. The passive position 12 (see Figs. 1, 2 and 11) may be
`defined as the position or state of the tool before perfo-
`rating charges (identified as “30” below) have been
`detonated or set-off. The active position 14 (see FIGS.
`1, 3 and 10) may be defined as the position or state of the
`tool after perforating charges have been detonated to
`perforate any cement, generally illustrated as 16, that
`surrounds the tool 10 within a well bore, generally
`illustrated as 18. The tool 10 connects at its extremities
`to casing 20-20 in a manner of becoming an integral
`part of a string of casing 20. The position of the tool 10
`within a string of casing 20 is to be within or diametri-
`cally across a pay zone or hydrocarbon reservoir 24 (see
`FIGS. 1, 9 and 10). Although the tool, 10 will be de-
`scribed hereafter for horizontal well completion (see
`FIG. 1) as is its primary goal and use, it is to be under-
`stood that the spirit and scope of the present invention
`is to include use or employment of the tool 10 for any
`purpose.
`The tool 10 has a generally tubular body, generally
`illustrated as 40, that is designed for the size of the well
`bore 18. The tubular body 40 is formed with a tubular
`coupling (i.e. an upper coupling), generally illustrated
`as 42, and a tubular coupling (i.e. a lower coupling),
`generally illustrated as 44. The upper coupling 42 is
`designed for the dimensions of the casing 20 and has
`internal threads 46 for threadably engaging casing 20.
`The lower coupling 44 has external threads 50 which
`are also for threadably engaging casing 20, and further
`has an internal perimeter 52 with a cylindrical recess 54.
`The generally tubular body 40 is also formed with a
`plurality of body apertures 55 (see FIG. 6) wherein and
`into shear pins (identified as 110 below) protrude. The
`generally tubular body 40 has an internal tubular bore
`58 that gradually diminishes into internal tubular bore
`60 through or via a cylindrical slanted or beveled sur-
`face 62. The internal tubular bore 58 has an internal
`diameter that is equal to the internal diameter of the
`upper coupling
`The tool 10 has a sleeve member, generally illustrated
`as 66, that includes a sleeve outside surface 68 which is
`slidably disposed on the surface of the internal tubular
`bore 60. The sleeve member 66 has a sleeve inside sur-
`face 70 with an internal diameter that is equal to the
`internal diameter of the lower coupling 44. An extreme
`end (i.e. an upper sleeve end) 74 of the sleeve 70 defines
`an arcuate surface; more specifically the extreme end 74
`defines a cylindrical or circular arcuate surface that
`generally registers with the beveled surface 62 (see
`FIG. 5) when the tool 10 is in the passive position 12.
`An extreme end (i.e. a lower sleeve end) 78 defines a
`lower sleeve perimeter (i.e. a lower sleeve perimeter 78)
`formed with and having a lower sleeve circular lug 80
`that seats in recess 54 when the tool is in the active
`position 14 as best shown in FIG. 10. The sleeve outside
`surface 68 of the sleeve member 66 has an upper exter-
`nal recess 84 wherein an O-ring seal member 86 is to be
`inserted and seats for slidably, sealably passing against
`the internal tubular bore 60. Similarly, a lower external
`recess 88 is formed in the sleeve outside surface 68 for
`receiving and seating an O-ring seal member 90 which
`also slidably, sealably passes against the internal tubular
`bore
`Diametrically across from the lower external recess
`88 is a lower internal recess 92 for receiving a plug
`nipple or seat, generally illustrated as 94. The lug nipple
`or seat, designed and dimensioned for receiving and
`
`Page 11 ofl5
`
`

`
`5,449,039
`
`5
`seating a plug, generally illustrated as 96. When two or
`more tools 10 are serially employed in a spaced relation-
`ship for interconnecting or coupling casing 20 together,
`such as illustrated in FIGS. 1 and 11, the diameters of
`the openings of the plug nipples or seats 94 of the re-
`spective tools 10 decrease towards the bottom or ex-
`treme end of the well bore 18. The respective plugs 96
`passing through casing 20 for seating in the respective
`seats 94 of the respective tools 10 also diametrically
`decrease. Thus, as best shown in FIG. 11, a tool 10a has
`a seat 940 with a seat opening 94ao whose diameter is
`less than or smaller than a seat opening 94bo of a seat
`94b in a tool 10b that is uphole from the tool such that
`a plug 96a, that has been dimensioned to seat in seat 94a
`by having a diameter that is less than or smaller than the
`seat opening 94bo of the seat 94b, may pass through the
`seat opening 94-bo of the seat 9412, as shown by the dot-
`ted line representation in FIG. 11. Plug 961), which has
`been sized to seat in seat 94b, has a diameter larger than
`the plug 96a for seating in seat 94b and not passing
`through the seat opening of the seat 941; (see FIG. 11).
`Thus, the tools 10a, 10b, 10c, 10d, and 10:: in FIG. 1 are
`disposed such that tool 10a is farthest downhole and
`tool 10:: is farthest uphole with tools 10b, 10c, and 10d
`ascending uphole (in order stated) from the farthest
`downhole tool 10a towards the farthest uphole tool
`10e. The seat openings (e.g. 94bo and 94410) of the re-
`spective seats 94 in the tools 10:2’, 10c, 10b, and 10a
`decrease from tool 109 to tool Similarly, the respective
`plugs 96 (e.g. 96b and 96a) for seating in the respective
`seats 94 (e.g. 94b and 94a) of the tools 10d, 10a, 10b, and
`10a have decreasing diameters such that the plug 96a
`that is to seat in seat 940 of tool 10a can pass through the
`seat openings of the seats 94 for tools we, 10d, 10c and
`10b and such that further the plug 96b that is to seat in
`seat 94b of tool 101: can pass through the seat openings
`of the seats 94 for tools we, 10d, and 10c, etc. and so
`forth. Obviously, the plug 96 that is to seat in seat 94 of
`tool 10:: has the largest diameter of all plugs and will
`stop travelling (or being pumped) through casing 20
`when seating in seat 94 of tool 105*.
`The sleeve member 66 also has a plurality of sleeve
`openings 100 with releasable covers 102 (i.e. disk that
`are capable of being ruptured). As will be further ex-
`plained below, when the tool 10 is in the passive posi-
`tion 12 (see FIG. 5) the sleeve openings 100 are not
`aligned with transverse charge recesses (identified as
`130 below) and only align with transverse charge reces-
`ses when in the active position 14 (see FIGS. 9 and 10).
`The releasable covers 102 are capable of being removed
`from and over the sleeve openings 100 by explosion of
`perforating charges (identified as “30” below) when the
`tool 10 is in the active position 14 (see FIG. 10). As best
`shown in FIGS. 5 and 7, a shear pin 106, which is manu-
`factured from a material (e.g. aluminum) that is capable
`of being severed in order to posture the tool 10 in the
`active position, is secured to the sleeve member 66 and
`protrudes outwardly therefrom. As previously indi-
`cated and as best shown in FIG. 6, shear pins 110 are
`connected to the sleeve member 66 such as to protrude
`into the body apertures 55 and function for preventing
`premature sliding of the sleeve member 66.
`The tool 10 also comprises a firing pin and charge
`housing, generally illustrated as 200 and integrally se-
`cured to or formed with the generally tubular body 40.
`The firing pin and charge housing 200 comprises a fir-
`ing pin recess, generally illustrated as 111, a longitudinal
`charge recess 112 in communication with the firing pin
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`recess 200 and generally extending through the firing
`pin and charge housing 200 essentially in a parallel
`relationship to and with the sleeve member 66. The
`longitudinal charge recess 112 is interrupted by at least
`one transverse charge recess 130, preferably a plurality
`of transverse charge recesses 130, that extends through
`the firing pin and charge housing 200 m a normal rela-
`tionship to the longitudinal charge recess 112. The one
`or more transverse charge recesses 130 extend from the
`internal tubular bore 60 to the outside of the tool 10.
`The one or more transverse charge recesses 130 are also
`in communication with the sleeve outside surface 68
`when the tool 10 is in the passive position 12 (see FIG.
`5 by way of example). The transverse charge recesses
`130 are formed in the firing pin and charge housing 200
`such that when the tool 10 is in the active position 14
`(see FIGS. 9 and 10), the sleeve openings align and/or
`register with the transverse charge recesses The firing
`pin recess 111 is composed of an outside pin recess 118,
`which has a recess ceiling 119 and is preferably rectan-
`gular in configuration, and an inside pin slot 120 that
`extends from both (and communicates with both) the
`outside pin recess 118 and the internal tubular bore 60.
`The inside pin slot 120 has a slot floor 122 that supports
`a cutting head 124 which is slidably disposed against the
`sleeve outside surface 68 such that when the sleeve
`member 66 slides from the passive position 12 of FIG. 5
`to the active position 14 of FIG. 10, the shear pin 106 is
`severed by the cutting head 124. The order of severance
`of the shears pins 110 and the shear pin 106 is as follows:
`(i) initially shear pins 110 after plug 96 is pumped down
`through casing 20 into the sleeve number 66 and subse-
`quently pressurized after seating in plug seat 94; and (ii)
`shear pin 106 instantaneously thereafter (or within a
`split second or two subsequent thereto). A rectangular
`cover plate 128 (see FIG. 4) is conveniently disposed
`over the outside pin recess 128 to protect the below-
`identified internals thereof.
`A firing pin mechanism, generally illustrated as 134,
`is disposed in the outside pin recess 118. The firing pin
`mechanism 134 more specifically comprises a firing pin
`body 138, a firing pin collar 140 bound circumferen-
`tially to the firing pin body 138, and a firing pin guide
`shaft 142 secured to the firing pin body 138 and extend-
`ing therefrom generally parallel to the sleeve body 66
`for being embedded in the firing pin and charge housing
`200 as best shown in the FIG. 5. The shear pin 106
`extends from the sleeve member 66, through the inside
`pin slot 102, and into the outside pin recess 118 for
`engaging the undersides of a the pin collar 140 to bias-
`ingly support the firing pin body 138 from a shot mem-
`ber (identified as 160 below). The firing pin mechanism
`134 also includes the firing pin head flange 146 as being
`bound to and supported by the firing pin body 138. A
`spring member 150 helically surrounds the firing pin
`guide shaft 142 while being supported by and com-
`pressed between the firing pin head flange 146 and the
`recess ceiling 119 such that when the shear pin 106 is
`sheared by the cutting head 124, the shear pin 106 re-
`leases its biased support from under the firing pin collar
`140, causing the spring 150 to drive the firing pin body
`138 towards and eventually against or into a shot mem-
`ber (identified as 160 below).
`The firing pin mechanism 134 also comprises a firing
`pin guide bushing, generally illustrated as 156, for re-
`taining and guiding the firing pin body 138 within a
`confined space that allows the firing pin body 138 to be
`guided against or into a shot member (identified as 160
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`below) when the shear pin 106 is sheared by the cutting
`head 124. As best shown in FIGS. 5 and 7 the firing pin
`guide bushing 156 consists of a rectangular box-like
`bracket 158 having a base plate 162 and a first guide
`plate 164 and a second guide plate 166. As best illus— 5
`trated in FIG. 7, the first guide plate 164 is secured to
`the generally tubular body 4-0 for posturing the rectan-
`gular box-like bracket 158 in a suspended relationship
`with respect to the outside pin recess 118. The second
`guide plate 166 is not secured to the generally tubular
`body 40 or any other structure (see FIG. 7) but is essen-
`tially juxtaposed to and/or registers with the inside pin
`slot 120 such that the shear pin 106 may be slidable
`thereagainst while remaining under the firing pin collar
`14-0 and not slipping therefrom until the shear pin 106
`has been severed by the cutting head 124.
`A shot member 160 is lodged in the longitudinal
`charge recess 112 such as to cut-off communication
`between the longitudinal charge recess 112 and the
`outside pin recess 118 and protrude into the outside pin
`recess 118 towards the firing pin body 138. The shot
`member 160 extends a defined distance towards the
`firing pin body 138 such that when the shear pin 106 is
`sheared by the cutting head 124, the spring 150 drives or
`propels the firing pin body 138 into or against the shot
`member 60. A prima cord 170 is engaged to the shot
`member 160 and extends longitudinally through the
`longitudinal charge recess 112 such as to also pass
`through the transverse charge recesses 130. Engaged to
`and lodging in each transverse charge recess 130 is a
`perforating charge 30 which is essentially conically
`configured geometrically. Each perforating charge 30 is
`protected from contamination (e.g. cement 16) by a
`screwed cap 180 that threadably engages each trans-
`verse charge recess 130 to encapsulate each perforating
`charge 30 within each transverse charge recess 130.
`Each perforating charge 30 has enough explosive
`power such that when detonated by the firing pin body
`138 being impelled against the shot member 160, the
`screwed caps 180 are blown off and a perforation 190 is
`formed in the cement 16 that allows the hydrocarbon
`reservoir 24 to communicate with the inside of the tool
`10 via the transverse charge recesses and the sleeve
`openings 100, as best shown in FIG. 10.
`Continuing to refer to the drawings for operation of 45
`the invention and method for well fracturing stimula-
`tions, FIGS. 5,9 and 10 depict the single tool 10 which
`has been previously described. The tool 10 is connected
`to casing 20 such as to become an integral part of a
`string of casing 20-20 and is not to be removed there-
`from after use. The string of easing 20-20 including the
`tool 10 is run into the well bore 18 and cemented to
`form cement 16. After the tool 10 has been intercon-
`nected to and with casing 10 to form a string of easing
`20-20 and subsequently cemented after being run into
`the well bore 18, the latter typically contains fluids (e. g.
`mixtures containing water and muds, etc.). The plug 96
`is disposed in the fluids within string of casing 20-20
`and pumped down towards the tool 10, more specifi-
`cally towards the plug nipple or seat 94 of the tool The
`plug 96 has been perfectly sized to seat in and mate with
`the plug nipple or seat 94. When the plug 96 has settled
`into the seat 94, the tool 10 may now be transferred
`from the passive position 12 to the active position 14 by
`the following procedure: after the plug 96 has mated
`with the seat 94, pump pressure on fluids within the
`casing string 20-20 and on top of the seated plug 96 is
`increased to cause the set of shear pins 110 (see FIG. 6)
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`to shear. Substantially instantaneously thereafter, the
`sleeve member 66 commences to move and drive the
`shear pin into the cutting head 124 whereupon it
`is
`severed; allowing subsequently the sleeve member 66 to
`move, contact, and mate with the lower coupling 44, all
`from continual pressure on the plug 96. The sleeve
`member 66 mates with the lower coupling 44 by the
`lower sleeve circular lug 80 seating in the recess 54 and
`the lower sleeve perimeter 78 being in flush contact
`with the internal perimeter 52 as best shown in FIGS. 9
`and 10. As the sleeve member 66 is mating with the
`lower coupling 44,
`the transverse charge recess 130
`align with the sleeve opening 100. When and after the
`shear pin 106 has been severed, the biased engagement
`of the shear pin 106 with the underside of the firing pin
`collar 140 is released to allow the spring 150 to propel
`the firing pin body 138 against the shot member 160. As
`was previously indicated, FIG. 9 is a partial vertical,
`segmented view of the tool 10 after the pressurized plug
`96 has moved the sleeve member 66 and released the
`firing pin body 138 against and in contact with the shot
`member 160 (i.e. a detonator) and immediately, instanta-
`neously before the perforating charges 30 (i.e. explo-
`sives) have exploded. The perforating charges 30 ex-
`plode and drive away caps 180 and covers 102, as well
`as perforating the cement 16 and forming perforations
`190 as best shown in FIG. 10. The hydrocarbon reser-
`voir 24 may now be stimulated (e.g. fracturing) without
`the necessity of setting bridge plugs or packers to isolate
`the hydrocarbon reservoir
`When two or more tools 10 are interconnected in a
`casing string 20-20, the respective seats 94 decrease in
`size towards the bottom of the well bore 18 More spe-
`cifically and as was previously indicated, when two or
`more tools 10 are serially employed in a spaced relation-
`ship for interconnecting or coupling casing 20 together,
`such as illustrated in FIGS. 1 and 11, the diameters of
`the openings of the plug nipples or seats 94 of the re-
`spective tools 10 decrease towards the bottom or ex-
`treme end of the well bore 18. The respective plugs 96
`passing through casing 20 for seating in the respective
`seats 94 of the respective tools 10 also diametrically
`decrease. Thus, as best shown in FIG. 11, the tool 10a
`has the seat 94a with the seat opening 94ao whose diam-
`eter is less than or smaller than the seat opening 94120 of
`the seat 9412 in the tool 10b that is uphole from the tool
`10a such that the plug 96a, that has been dimensioned to
`seat in seat 94a by having a diameter that is less than or
`smaller than the seat opening 94bo of the seat 94b, may
`pass through the seat opening 94bo of the seat 9417, as
`shown by the dotted line representation in FIG. 11.
`Plug 96a seats in seat 94a and with pressurization, the
`pins 110 and pin 106 shear (in order stated) and the
`previously stated perforation procedure for the single
`tool 10 is repeated. The hydrocarbon reservoir 24 in
`proximity to the tool 100 is stimulated, and the entire
`procedure for tool 10b may now be repeated. More
`