BAKER HUGHES INCORPORATED AND
`BAKER HUGHES OILFIELD
`OPERATIONS, INC.
`Exhibit 1016
`BAKER HUGHES INCORPORATED AND
`BAKER HUGHES OILFIELD
`OPERATIONS, INC. v. PACKERS PLUS
`ENERGY SERVICES, INC.
`IPR2016-00596
`
`Page 1 of 8
`
`

`
`United States Patent
`
`[19]
`
`Weitz
`
`[11]
`
`[45]
`
`4,279,305
`
`Jul. 21, 1981
`
`[57]
`
`ABSTRACT
`
`A well washing tool which may comprise: a tubular
`mandrel; first and second packer assemblies carried on
`the mandrel at opposite ends thereof; an outer tubular
`body surrounding the mandrel between the packer as-
`semblies; an annular chamber between the mandrel and
`the surrounding tubular body; and a valve assembly
`carried within the annular chamber. The tubular man-
`drel is adapted for connecting the tool in a pipe string
`extending to the surface of the well and the lower end
`may be adapted for blocking flow of fluids from the
`pipe string through the mandrel flow passage. Ports are
`provided in the walls of the mandrel and the tubular
`body permitting fluid communication between the man-
`drel flow passage and the exterior of the tool. The valve
`assembly prevents such fluid communication by block-
`ing one or more of the ports. The packer assemblies are
`actuated by a predetermined pressure and the valve
`assembly is responsive to a higher predetermined pres-
`sure to unblock the ports permitting fluid communica-
`tion between the mandrel flow passage and the exterior
`of the tool through the annular chamber.
`I
`
`19 Claims, 2 Drawing Figures
`
`[54] WELL VWASHING TOOL AND METHOD
`[75]
`Inventor: Robert D. Weitz, Houma, La.
`
`[73] Assignee:
`
`Top Tool Company, Inc., Houma, La.
`
`[21] Appl. No.: 65,520
`
`[22] Filed:
`
`Aug. 10, 1979
`
`[51]
`Int. Cl.3 .................... .. E21B 37/00; E21B 33/124
`
`[52] U.S. Cl. ..
`............ .. 166/312; 166/147;
`166/187
`[58] Field of Search ............. .. 166/127, 147, 151, 191,
`166/187, 312, 311
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`8
`
`166/147
`4/1931 Newlin .............................
`.. 166/147
`6/1931
`Lane et al.
`.. 166/187
`3/1953 Humason .
`.. 166/147
`8/1955
`Fewel .... ..
`.. 166/187
`9/1961 Gawlik .
`.. 166/187
`10/1962 Brown .. .
`.. 166/147
`2/1965
`Bateman ..
`8/1965
`Loomis ............................... .. 166/147
`
`
`
`1,802,525
`1,808,958
`2,633,200
`2,715,444
`2,998,721
`3,059,699
`3,169,580
`3,199,598
`
`Primary Examiner—James A. Leppink
`Attorney, Agent, or Firm—Bill B. Berryhill
`
`31$;
`l|Vb?‘‘—JIAri“?!
`1
`-(Z3112
`_ Q‘;
`vpwntnnc$11
`5A1an
`'A‘VA""
`
`D
`
`Ox‘0to\AA\N§°A.‘A
`
`9,.7
`
`
`ESL‘.-rug5‘hs-.uiww"">‘=:.‘.‘.',’.‘l.'arn
`
`
`
`
`
`‘‘V's.““_}?_.-V1.31:37.12:“'aI.'nvlI.'4|I2I’1'IrA'.Iv.lian.
`
`Page 1 of 8
`Page 1 of 8
`
`

`
`tHC..I.aPS”U
`
`Jul. 21, 1981
`
`4
`
`,279,306
`
`P
`
`
`
`.‘3..s\><I$‘.s\.fi./..‘I‘3~.x..§I‘.....hIl.....IV‘.....I‘....I..
`
`r3G.
`
`0mmQ_E_m_——M
`
`‘.allutmvihfiuufliluqluEmnuwfiummfinfiliwilufi...
`fl._I.IIII-In-Iiluhufifllr..__I
`
` \.£......a..,..alVIrE."..r'I.ril.r‘v4.Ihar...ll:liIn'n'lil.E'%.Nx1§afl.r.h! -_§33.
`\.N?5.\..;..
`
`3.In.—kl
`
`»_1uh\Ihu.I.\
`
`
`
`I-
`
`
`
`
`
`l
`
`0.
`
`
`
`
`
`0235405//S_.022.4/.622fifi«M344/M%5373530.67M
`
`7
`
`yr5O5
`
`\\\\
`
`
`
`
`
`
`
`.l|.|nll».1|.[MF“I11!”_ll-xi...Ii...li...‘-I‘.‘\...l‘EEKIE‘!
`
`
`
`i‘.b..§..c.rnIi4"‘.'r“‘i.in’EDA!’‘tn?1
`| 42424H/3II:
`2,rll9/3mo7/oox,,xM.
`I._'.-Iluylrilllllmzgl
`
`
`33_.I|_._zxr...‘ i..Lfi£I....2.I\\3
`
`
`
`
`1./<..I.....I/<..s
`
`uI«I1,|Iln.=.VIV.i\..Eli‘!-.Iv'L‘Ili.-nsi..!I—i‘...h;.
`
`7 3
`
`3
`
`3/
`
`C
`
`i
`
`V 34
`
`Page 2 of 8
`Page 2 of 8
`
`ill
`
`0
`
`
`
`u—
`\‘
`
`
`
`
`
`
`
`
`
`
`

`
`1
`
`WELL WASHING TOOL AND METHOD
`
`BACKGROUND OF THE INVENTION
`
`4,279,306
`
`1. Field of the Invention
`The present invention pertains to tools for use in
`completing oil and/or gas wells. Specifically, it pertains
`to a washing tool and method suitable for circulating
`fluid through well conduits and surrounding formations
`for various treatments thereof.
`.
`2. Description of the Prior Art
`In completing an oil or gas well after drilling a hole
`therefor, it is common to install a production casing and
`to perforate the casing at
`the producing formation.
`After completion, the oil and/or gas flows from the
`formation through the perforations into the production
`casing where it is usually communicated to the surface .
`of’ the well through production tubing.
`Frequently it is necessary or desirable to treat the
`formation surrounding the perforated casing in some
`way to enhance the flow of fluids therefrom. Some
`methods of treating formations include circulating
`water or acidized fluid through the formation via the
`casing perforations and back up the casing string. By
`such circulation, loose sands may be washed from the
`formation or consolidated with various materials. Voids
`may be created for more effective gravel packing, tight
`formations may be made more susceptible to flow, etc.
`In performing such circulating operations, various
`washing tools have been developed which generally
`provide some method of packing off an area of the
`casing for circulation. Such tools are usually attached to
`the lower end of a washing string, lowered into the
`casing to the desired depth, packed off and circulating
`commenced. In most of the tools of the prior art, pack-
`ing is accomplished by providing packers on the wash-
`ing tools on opposite sides of the perforations through
`which the fluid is to flow from the tool. Circulating
`fluid flows down the circulating string, through the
`tool, between the packers and out the casing perfora-
`tions into the formation. Flow then continues back into
`the casing through perforations above the packers so
`that the returning fluid flows upwardly through the
`casing above the tool.
`The packers used in washing toolsof the prior art are
`usually of the cup type. Prior art washing tools utilizing
`cup type packers are made by the Baker Division of
`Baker Oil Tools, Inc. and Cavins Corporation. Cup
`type packers leave something to be desired. in depend-
`ability, failing to adequately seal under many condi-
`tions. Furthermore, since the cup type packers engage
`the casing while the tool is being run into the well or
`pulled- out of it, they are frequently torn or damaged
`during use.
`,
`Upon completion of circulation, it may be desirable
`to reverse circulate for removing sand or other materi-
`als from the bottom of the well hole. This is difficult to
`effectively accomplish with cup type packers since the
`packers remain engaged with the casing and since some
`of them may be flared in a direction which would actu-
`ally oppose reverse flow. Another problem associated
`with cup type packers is the possibility of swabbing in
`the well or pulling sand into the casing when the tool is
`removed therefrom.
`
`l0
`
`l5
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`SUMMARY OF THE INVENTION.
`
`65
`
`In the present invention a circulating or washing tool
`and method are provided which eliminate many of the
`
`2
`problems associated with cup type packer washing
`tools. The tool of the present invention includes a tubu-
`lar mandrel having a flow passage therethrough and the
`upper end of which is adapted for connecting the tool in
`a pipe string extending to the surface of the well, the
`lower end being provided with means for blocking the
`flow of fluids from the pipe string through the mandrel
`flow passage. First and second packer assemblies are
`carried on the mandrel at the opposite ends thereof and
`an outer tubular body surrounds the mandrel between
`the packer assemblies. An annular chamber is provided
`between the mandrel and the surrounding tubular body.
`The annular chamber is in fluid communication with the
`mandrel flow passage through ports in the walls of the
`mandrel and the tubular body is provided with ports
`which permit fluid communication between the annular
`chamber and the exterior of the tool.
`A valve assembly is carried within the annular cham-
`ber blocking the ports in the tubular body and prevent-
`ing fluid communication between the annular chamber
`and the tool exterior. However, the valve assembly is
`responsive to predetermined pressure communicated to
`the annular chamber through the mandrel ports to un-
`block the tubular body ports ‘permitting fluid communi-
`cation between the mandrel flow passage and the tool
`exterior through the mandrel ports, the annular cham-
`ber and the tubular body ports. The packer assemblies
`are also responsive to a predetermined pressure commu-
`nicated to the annular chamber through the mandrel
`ports for actuation thereof. In fact, the packer assem-
`blies are responsive to a lower predetermined pressure
`than the valve assembly. Thus, the packer assemblies
`may first be set and then the valve assembly actuated to
`provide the fluid communication necessary for circulat-
`ing fluids through the tool for washing the surrounding
`formation.
`
`The tool is operated by lowering on a pipe string to
`the necessary level in a perforated casing. Then the
`lower end of the mandrel flow passage is closed or
`blocked by suitable means and pressure.applied to the
`annular’ chamber through the pipe string. Upon reach-
`ing a first predetermined pressure level,
`the packer
`assemblies are axially compressed and radially ex-
`panded until they sealingly engage the walls of the
`surrounding perforated casing. A further increase in
`pressure actuates the valve assembly to open tubular
`body ports and fluids in the pipe string begin to flow to
`the exterior of the tool through the perforations isolated
`by the packing assemblies and into the surrounding well
`strata. The fluid reenters the casing string through per-
`forations above the packer assemblies for return to the
`surface of the well. After circulation, pressure in the
`annular chamber is relieved, allowing the valve assem-
`bly to close and the packer assemblies to disengage the
`casing walls. Reverse circulation may be performed to
`clean sand or debris from the bottom of the hole.
`Thus, the circulating or washing tool of the present
`invention is simple in construction and operation. Due
`to the hydraulically set packers, it is more reliable than
`washing tools utilizing cup type packers. Furthermore,
`such construction permits the tool to be lowered in the
`well without interference between the packing elements
`and the casing string so that the packing elements are
`not damaged on lowering into the well. The tool is
`short and compact, allowing it to pass through tight
`areas or slightly out of line casing sections. In addition,
`after circulation and release of pressure, the packing
`
`Page 3 of 8
`Page 3 of 8
`
`

`
`4,279,306
`
`3
`assemblies are radially contracted for reverse circula-
`tion and removal so that there‘ is no danger of swabbing
`in the well or pulling sand into the casing while the tool
`' is being removed.
`Many other advantages of the tool will be understood
`from reading the specification which follows in con-
`junction with the accompanying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a sectional-elevation view of easing within
`a well hole showing the washing tool of the. present
`invention in quarter—section and in the unset or running
`in position; and
`FIG. 2 is a sectional elevation view similar to FIG. 1
`but showing the tool in its set position for circulation of
`fluids through the tool and the casing perforations into
`the surrounding formation.
`
`DESCRIPTION OF A PREFERRED
`EMBODIMENT
`
`Referring first to FIG. 1, there is shown the washing
`tool T of the present invention attached to the lower
`end of a pipe string P in a perforated casing C of a well
`having surrounding strata S. The tool T includes a tubu-
`lar mandrel 1 having a central flow passage 2 there-
`through and the upper end of which is provided with
`means such as threads 3 for connecting the tool to the
`pipe string P which extends to the surface of the well.
`The lower end of the mandrel may be threadedly con-
`nected at 4 to a ball sub 5 or the like, the purpose of
`which is to block flow of fluids from the pipe string
`through the mandrel flow passage when desired. How-
`ever, in FIG. 1, there is no blockage and flow is permit-
`ted through the mandrel flow passage 2 so that if there
`is any fluid in the casing C, it may be displaced up-
`wardly through the pipe string P as the tool T is low-
`ered into the well. Other tools 0, may be attachedto the
`ball sub if desired.
`First and second packer assemblies 6 and 7 are carried
`at opposite ends of the mandrel. These assemblies 6 and
`7 will be more fully described hereafter. An outer tubu-
`lar body 8 surrounds the mandrel 1 between packer
`assemblies 6 and 7 leaving an annular chamber 9 there-
`between.
`The annular chamber 9 is in fluid communication
`with the mandrel flow passage 2 through at least one
`port 10. The tubular body 8 is provided with a plurality
`of ports 11 which under certain conditions permit fluid
`communication‘ between the annular chamber 9 and the
`exterior of the tool T.
`’
`,
`Carried within the annular chamber 9 is a valve as-
`sembly, including a differential piston member 12 and
`biasing spring 13, which in the running position of FIG.
`1 blocks the ‘ports 11 preventing fluid communication
`between the annular chamber 9 and the exterior of the
`tool. The valve assembly will be more fully described
`hereafter.
`Each of the packer assemblies 6 and 7 includes a
`tubular packer body 20, 30, which is carried on the
`mandrel 1 having an annular shoulder 21, 31 and an
`annular lip 22, 32,
`thereon. A plurality of resilient
`packer elements 23, 24, 33, 34, surround the packer
`bodies 20, 30 adjacent the annular shoulders 22, 32, and
`may be separated by ring spacers 25, 35. Each packer
`assembly may also be provided with an annular retainer
`ring 26, 36 which may also have an annular lip 27, 37,
`thereon.
`'
`
`4
`Each packer assembly also includes an annular piston
`comprising an_annular head portion 40, 50 and a tubular
`sleeve portion 41, 51 extending therefrom. The head
`portion slidingly and sealingly engages the exterior of
`mandrel 1 and the interior of tubular body 8. The sleeve
`portion 41,’ 51 slidingly and sealingly engages the exte-
`rior of the respective packer bodies 20, 30. Annular
`seals 42, 43, 44 and 52, 53, 54 assure sealing at these
`points of sliding and sealing engagement. It will noted
`that in the unset position shown in FIG. 1, the head ends
`of the pistons rest against snap rings 45, 55 attached to
`the tubular body 8 and the sleeve ends 41, 51 bear
`against the packer retainer rings 26, 36.
`The sleeve portions 41, 51 and the inner diameter of
`the head portions 40 and 50 of the packer pistons are
`joined by annular surfaces 46, 56 which along with the
`sleeve portions 41, 51, mandrel 1 and the ends of packer
`bodies 20 and 30 form variable annular chambers 47, 57.
`These variable annular chambers 47, 57 may be vented
`to the exterior of the tool through longitudinal ports 48,
`58 and radial ports 49, 59.
`It will also be noted that the packer bodies 20 and 30
`are shown attached to the mandrel 2 by threaded con-
`nections 20a and 30:: allowing removal of the packer
`body from the mandrel 1. This then would also permit
`removal of all of the elements of the packer assembly
`including the packer elements and the packer pistons.
`In examining the interior of the tubular body 8, it will
`be seen that it is provided with a first cylindrical surface
`60 and an adjacent second cylindrical surface 61 of
`slightly smaller diameter. The differential piston 12 of
`the valve assembly is provided with a corresponding
`first cylindrical end portion 62 and a second cylindrical
`opposite end portion 63 of smaller diameter. The end
`portion 62 slidingly and sealingly engages cylindrical
`surface 60 of tubular member 8 and the opposite end
`portion 638 slidingly and sealingly engages a second
`smaller diameter cylindrical surface 61 of the tubular
`member 8. Thus the effective annular area exposed to
`pressure in theyannular chamber 9 is greater at the first
`end portion 62 than at the second opposing end portion
`63. Annular seals 64 and 65 assure sealing at these points
`of contact. ‘At least one relief portion 66 is provided
`through the walls of the tubular member 8'between the
`first and second annular seals 64 and 65 through which
`‘fluids these seals may be displaced to the exterior of the
`tool. A small bleed port 67 may be provided in the walls
`of the tubular_ member 8 in direct communication with
`annular chamber 9.
`the valve assembly in-
`As previously mentioned,
`cludes a biasing spring 13 between the differential pis-
`ton member and a spring retainer 13a at the fixed. snap
`ring 55. The biasing spring 13 biases the piston 12
`toward the position of FIG. 1, blocking ports 11.
`STATE OF OPERATION
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`To utilize the tool T for circulating operations, it is
`attached to the pipe string P and lowered into the perfo-
`rated casing _c to the desired depth in the unset position
`illustrated in FIG. 1. Then a resilient ball member B is
`dropped through the pipe string P through the mandrel
`passage 2 _for engagement with seating surface 5a of the
`ball sub 5. (See FIG. 2) This blocks flow at the end of
`the mandrel flow passage 2. Then, pressure is increased
`through the pipe string P, fluid entering the annular
`chamber 9 through mandrel ports 10. As pressure is
`increased to a first predetermined level, the pressure
`exerted against the packer piston head portions 40, 50,
`
`65‘
`
`Page 4 of 8
`Page 4 of 8
`
`II
`
`

`
`«r
`
`5
`forces the pistons toward the packing elements 23, 24,
`33, 34, axially compressing them between the respective
`annular shoulders 21, 26, until
`they are radially ex-
`panded to sealingly engage the inner walls of the casing
`C. Any fluids in the variable annular chambers 47 and
`57 are displaced through ports 48 49, 58, 59. The set
`position of the packers 6 and 7 are shown in FIG. 2.
`A further increase in pressure to a higher predeter-
`mined level forces the differential piston 12 of the valve
`assembly downwardly, as viewed in FIG. 2, compress-
`ing the biasing spring 13. This is due to the differential
`pressure area of the piston 12 previously described
`herein. As the piston 12 moves downwardly, any fluids
`between seals 64 and 65 are displaced through the relief
`port 66 and the tubular member ports 11 are opened, as
`seen in FIG. 2. Fluid then flows from the pipe string P
`through the mandrel flow passage 2, ports 10, annular
`chamber 9, and ports 11, to the exterior of the tool.
`Since the casing is sealed or packed off by the packer
`assembly 6 and 7, the fluid exiting through the ports 11
`continues through the perforations of the casing C be-
`tween the packer assemblies 6 nd 7 to enter the sur-
`rounding well strata S, washing the loose sand or treat-
`ing the strata in such a way as to create a surrounding
`zone or area Z for improving the flow characteristics of
`the well. The circulating fluid and materials carried
`therewith then reenter the casing C through perfora-
`tions above the packing assembly 6 where the fluids and
`entrained materials continue to the surface of the well
`for disposal.
`After it
`is determined that enough circulation has
`occurred, pressure is relieved from the pipe string and
`consequently, the annular chamber 9 of the tool T. As
`pressure is relieved, the differential piston 12 returns to
`the blocked position of FIG. 1 due to the reduction in
`pressure and the force of biasing spring 13. Further
`reduction in pressure allows the packing elements 23, 24
`and 33, 34, to radially contract and axially expand, forc-
`ing the packer pistons to return to the initial position of
`FIG. 1.
`
`If desired, flow can then be reversed down the casing
`through the perforations above the packing assemblies 6
`into the washed out zone Z and around the packing
`elements 6 and 7 to beneath the ball sub 5. Further
`circulation will cause the ball B to be displaced to the
`surface of the well for removal. Reverse circulation
`may continue off the bottom of the well hole, causing
`any sand or debris at the bottom of the well hole to be
`removed from .the well through mandrel flow passage 2
`and the pipe string P.
`The entire tool T may be removed from the well by
`lifting it on the pipe string P. Since the packing assem-
`blies 6 and 7 are now unset, there is no danger of swab-
`bing in the well or pulling sand into the casing by creat-
`ing a vacuum therein. Furthermore, the packing ele-
`ments 23, 24, 34, 31 are not damaged as the tool is re-
`moved.
`‘
`.
`Another feature of the tool of the present invention is
`the ability to reperforate the well if the first casing
`perforations are not sufficient, without completely re-
`moving the tool. If the ball sub 5 is replaced by a full
`bore opening valve, this can be done by opening the
`valve and lifting the tool in the pipe string P for a short
`distance. Then, a tubing gun can be lowered through
`the pipe string P, the full opening flow passage 2 of the
`mandrel and the valve, to a position below the tool T
`and perforation performed. Then the perforating gun
`can be removed, the tool T lowered again and circulat-
`
`4,279,306
`
`5
`
`6
`ing repeated. This eliminates the need to completely
`remove the tool T from the well saving the time neces-
`sary for doing so with tools of the prior art.
`Thus, it is seen from the foregoing description that
`the washing tool of the present invention is extremely
`efficient, easy to use and versatile. Furthermore, it is
`relatively simple to manufacture and maintain. While a
`single embodiment of the invention has been described
`. herein, many variations can be made without departing
`10
`from the spirit of the invention. Therefore, it is intended
`that the scope of the invention be limited only by the
`claims which follow.
`I claim:
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`1. A well washing tool comprising:
`a tubular mandrel having a flow passage there-
`through and the upper end of which is open and
`provided with means for connecting said tool in a
`pipe string extending to the surface of a well and
`the lower end of which is normally open but which
`may be provided with means for blocking flow of
`fluids from said pipe string through said mandrel
`flow passage;
`_
`first and second packer assemblies carried on said
`mandrel at opposite ends thereof;
`an outer tubular body surrounding said mandrel be-
`tween said packer assemblies;
`an annular chamber between said mandrel and said
`surrounding tubular body, said annular chamber
`being in fluid communication with said mandrel
`flow passage through first port means provided in
`the walls of said mandrel, said tubular body being
`provided with second port means permitting fluid
`' communication between said annular chamber and
`the exterior of said tools; and
`valve means carried within said annular chamber
`independently of said packer assemblies blocking
`said second port means and preventing said fluid
`communication between said annular chamber and
`said tool exterior but responsive to predetermined
`pressure communicated to said annular chamber
`through said first port means to unblock said sec-
`ond port means permitting fluid communication
`between said mandrel flow passage and said tool
`exterior through said first port means, said annular
`chamber and said second port means.
`2. A well washing tool as set forth in claim 1 in which
`each of said packer assemblies comprises a tubular
`packer body carried by» said mandrel having‘ an annular -
`shoulder thereon, at least one resilient packer element
`surrounding said packer body adjacent said annular
`shoulder and an annular piston member slidingly engag-
`ing the exterior of said packer body and one end of
`which is exposed to pressure within said annular cham-
`ber, said piston, member being responsive to predeter-
`mined pressure, lower than said predetermined pressure
`for response of said valve means, communicated to said
`annular chamber through said port to move toward said
`annular shoulder axially compressing said packer ele-
`ment therebetween and forcing said packer element to
`radially expand without unblocking of said second port
`means by said valve means.
`3. A well washing tool as set forth in claim 2 in which
`said packer assembly includes a retainer ring slidingly
`surrounding said packer body between said packer ele-
`ment and said annular piston member, said packer ele-
`ment being compressible between said retainer ring and
`said annular shoulder upon said movement of said pis-
`ton member in response to said predetermined pressure.
`
`Page 5 of 8
`Page 5 of 8
`
`

`
`4,279,306
`
`i
`
`i
`
`i
`
`~
`
`10
`
`25
`
`30
`
`35
`
`8
`7
`valve means carried within said annular chamber
`4. A well washing tool as set forth in claim 2 in which
`blocking said second port means and preventing
`said packer body is removably attached to said mandrel,
`said fluid communication between said annular
`removal of said packer body from said mandrel permit-
`chamber and said tool exterior but responsive to
`'ting removal of said packer element and said piston.
`member from said mandrel.
`predetermined pressure communicated to said. an-
`nular chamber through said first port means to
`5. A well washing tool as set forth in claim 2 in which
`unblock said second port means permitting fluid
`said valve means includes biasing means, independent of
`communication between said mandrel flow passage
`said packer assemblies, by which said valve means is
`and said tool exterior through said first port means,
`biased toward said blocking position, said biasing means
`said annular chamber and said second port means;
`capable of being overcome by said predetermined pres-
`and
`
`
`sure in said annular chamber to permit movement of
`first and second packer assemblies carried on said
`said valve means to said unblocked position.
`mandrel at opposite ends thereof, each of said
`6. A well washing tool as set forth in claim 1 in which
`packer assemblies comprising a tubular packer
`the interior of said outer tubular body is provided with
`body carried by said mandrel having an annular
`a first cylindrical surface and an adjacent second cylin-
`drical surface of smaller diameter andin which said
`shoulder thereon, at least one resilient packer ele-
`ment surrounding said packer body adjacent said
`valve means comprises an annular differential piston
`annular shoulder and an annular piston member.
`member, the exterior of which is provided with a first
`having an annular head portion an inner surface of
`cylindrical end portion slldingly and sealingly engaging
`which slidingly and sealingly engages said mandrel
`said first cylindrical surface of said tubular body and a
`and an outer surface of which slidingly and seal-
`second cylindrical opposite end portion of smaller di-
`ingly engages said tubular body, and a tubular
`ameter slidingly and sealingly engaging said second
`sleeve portion extending from said head portion for
`cylindrical surface of said tubular body so that the effec-.
`slidingly and sealingly engaging the exterior of said
`tive annular area exposed to said predetermined pres-
`packer body, the end of said head portion being
`sure ln said annular chamber is greater at said first end
`exposed to pressure within said annular chamber so
`portion than at said second opposing end portion.
`that said piston member is responsive to predeter-
`7. A well washing tool as set forth in claim 6 includ-
`mined pressure communicated to said annular
`ing a first annular seal between said first cylindrical
`chamber through said first port means to move
`surface of said tubular body and said first cylindrical
`toward said annular shoulder axially compressing
`end portion of said differential piston member and a
`said packer element therebetween and forcing said
`second annular seal between said‘ second cylindrical
`packer element to radially expand.
`‘
`surface of said tubular body and said second cylindrical
`12. A well washing tool as set forth in claim 11 in
`end portion of said differential piston member.
`which said piston member sleeve portion and the inner
`8. A well washing tool as set forth in claim 7 includ-
`diameter of said annular head portions are joined by an
`ing a relief port through the walls of said tubular mem-
`annular surface, said sleeveportion, said mandrel, said
`ber between said first and second annular seals through
`annular surface and one endlof said tubular packer body
`which fluids between said first and second seals may be
`defining a variable volume annular chamber.
`
`
`displaced to the exterior of said tool.
`13. A well washing tool as set forth in claim 12 in-
`9. A well washing tool as set forth in claim 7 in which
`cluding third port means providing fluid communica-
`said valve means includes biasing means biasing said
`tion between said variable volume annular chamber and
`the exterior of said tool.
`differential piston toward a pisition in which said sec-
`ond port means is blocked by said first cylindrical end
`14. A well washing tool comprising:
`portion of said differential piston member, said differen-
`a tubular mandrel having a central flow passage
`tial piston member being movable against said biasing
`therethrough and the upper end of which is pro-
`means in response to said predetermined pressure in said
`vided with means for connecting said tool in a pipe
`annular chamber to unblock said second port means.
`string extending to the surface of a well and the
`10. A well washing tool as set forth in claim 9 in
`lower end of which may be provided with means
`which said biasing means comprises a helically wound
`for blocking flow of fluids from said pipe string
`spring disposed in said annular chamber between said
`through said flow passage;
`differential piston member and a fixed shoulder therein.
`first and second packer assemblies having annular
`11. A well washing tool comprising:
`sealing elements thereon carried on said mandrel at
`a tubular mandrel having a flow passage there-
`opposite ends thereof;
`,
`through and the upper end of which is provided
`an outer tubular body surrounding said mandrel be-
`with means for connecting said tool in a pipe string
`tween said packer assemblies;
`an annular chamber between said mandrel and said
`extending to the surface of a well and the lower
`end of which may be provided with means for
`surrounding tubular body;
`blocking flow of fluids from said pipe string
`first port means providing fluid communication be-
`through said mandrel flow passage;
`'
`tween said mandrel flow passage and said annular
`an outer tubular body surrounding said mandrel;
`chamber;
`an annular chamber between said mandrel and said
`second port means permitting fluid communication
`between said annular chamber and the exterior of
`surrounding tubular body, said annular chamber
`being in fluid communication with said mandrel
`flow passage through first port means provided in
`the walls of said mandrel, said tubular body being
`provided with second port means permitting fluid
`communication between said annular chamber and
`the exterior of said tool;
`
`said tool; and
`valve means carried, within said annular chamber
`comprising a differential piston member and a bias-
`ing member, said biasing member biasing said pis-
`ton member toward a position blocking said second
`_
`’ port means, said differential piston member includ-
`
`
`
`40.
`
`45
`
`50
`
`55
`
`65
`
`Page 6 of 8
`Page 6 of 8
`
`

`
`4,279,306
`
`9
`ing a first diameter portion slidingly and sealingly
`engaging a first cylindrical surface of the interior of
`said tubular body and a second smaller diameter
`portion slidingly and sealingly engaging a second
`cylindrical surface on the interior of said tubular
`body creating a first annular area facing away from
`biasing spring so that upon application of a prede-
`termined pressure level
`to said first and second
`annular areas within said annular chamber the dif-
`ferential
`force created thereby overcomes said
`biasing member forcing said piston member to a
`position unblocking said second port means.
`15. A well washing tool as set forth in claim 14 in
`which each of sid packer assemblies Comprises a tubular
`, packer body carried by said mandrel having an annular
`shoulder thereon, at least one of said annular sealing
`elements surrounding said packer body adjacent said
`annular shoulder and an annular piston member engag-
`ing the exterior of said packer body adjacent said seal-
`ing element and one end of which is exposed to pressure
`within said annular chamber and by which said sealing
`elements are axially compressed and radially expanded
`in response to a predetermined pressure level within_
`said annular chamber.
`
`16. A method of circulating fluid in a well having a
`perforated casing therein compring the steps of:
`attaching a washing tool to the lower end of a pipe
`string having an open end flow passage there-
`through, pressure responsive packing assemblies at
`opposite ends thereof, ports by which fluid com-
`munication may be established between said flow
`passage and the exterior of said tool, and valve
`means blocking said ports but pressure responsive
`to unblock said ports;
`lowering said washing tool on said pipe string to the
`desired circulation level within said perforated
`casing while allowing any fluids in said well to be
`displaced into said pipe string through said o