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`USO05765642A
`
`Umted St3t€S Patent
`
`[19]
`
`[11] Patent Number:
`
`5,765,642
`
`Surjaatmadja
`
`[45] Date of Patent:
`
`Jun. 16, 1998
`
`10/1934 Wang ....................................166/50X
`4,479,541
`233323 1311323 €"““§.i‘.§ *3‘
`1233233
`ran
`et
`.
`,
`,
`4,919,204
`4/1990 Bakeretal.
`155/223
`4,974,575 12/1990 Austin eta].
`166/250
`§°]‘.man et.a1‘
`166/250
`,
`_
`utjaatmadja ......
`166/308
`5,325,923
`7/1994 Suljaatmadjaet al
`166/308
`5.33s,724
`3/1994 Venditlo eta].
`166/298
`5,332,927 11/199: Frank .....(.1.........5
`...... $3/67
`5,3
`,957
`3/199
`s
`'
`tm ‘ et
`1
`03
`5,499,678
`3/1996 sflilmi/1}: ..........
`166/308 x
`Primary Examiner—George A. Suchfield
`Attome); Agent, or Firm—Stephen R. Christian; C. Clark
`Doughcrty. Jr.
`[57]
`
`
`
`ABSTRACT
`
`Methods of fracturing subterranean formations are provided
`The methods basically comprise positioning a hydrajetting
`tool having at least one fluid jet forming nozzle in the well
`bore adjacent the formation to be fractured and jetting fluid
`throu h the nozzle a ainst
`the formation at a
`ressure
`sufliciéent to form a fraiture in the formation.
`P
`
`20 Claims, 2 Drawing Sheets
`
`1
`
`PACKERS 1006
`
`[543 SUBTERRANEAN FORMATION
`FRACTURING ME“*°"S
`-
`.
`-
`-
`[75] mvcmon
`‘hm B‘ suuaaunadm Duncan‘ Okla‘
`[73] Assignee: Halliburton Energy Services, Inc..
`D“““‘“‘~ Okla‘
`
`[211 App]. No.: 774,125
`[221 Filed:
`Dec-23:19”
`[51]
`Int. Cl.‘ .......................... E21B 43/114; E21B 43/26;
`E2113 43/27
`......................... 166/297; 166/50; 166/177.5;
`166/307; 166/308; 299/17
`[58] Field of Search .............................. 166/50. 222. 223.
`166/1775. 250.1. 280. 307. 308. 325. 297;
`175/67; 405/55. 58. 73; 299/17
`
`[52] U.S. Cl.
`
`[55]
`
`R¢f€|‘911¢€S Cited
`U'S' PATENT DOCUMENTS
`9/1977 Tagirov et al.
`..................... 166/223 X
`8/1978 Denisan et a1.
`.......................... 299/17
`
`4,050,529
`4,103,971
`
`PACKERS 1006
`
`1
`
`

`
`U.S. Patent
`
`Jun. 16, 1998
`
`Sheet 1 of 2
`
`5,765,642
`
`
`
`/%
`'.'''1.‘-7-‘%w-n‘t r ‘\\ --"1
`7 . °.\~..-..|'/2‘-r.*"»y':'r<
`*
`\\\;,,.s.\\\ 2
`
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`
`
`2
`
`

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`U.S. Patent
`
`Jun. 16, 1993
`
`Sheet 2 of 2
`
`5,765,642
`
`3
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`

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`5.765.642
`
`1
`SUBTERRANEAN FORMATION
`FRACTURING METHODS
`
`BACKGROUND OF THE INVENTION
`
`l. Field of the Invention
`
`The present invention relates to improved methods of
`fracturing subterranean formations to stimulate the produc-
`tion of desired fluids therefrom.
`
`2. Description of the Prior Art
`Hydraulic fracturing is often utilized to stimulate the
`production of hydrocarbons from subterranean formations
`penetrated by well bores. In performing hydraulic fracturing
`treatments. a portion of a formation to be fractured is
`isolated using conventional packers or the like. and a frac-
`turing fluid is purnped through the well bore into the isolated
`portion of the formation to be stimulated at a rate and
`pressure such that fractures are formed and extended in the
`formation. Propping agent is suspended in the fracturing
`fluid which is deposited in the fiactures. The propping agent
`functions to prevent the fractures from closing and thereby
`provide conductive channels in the formation through which
`produced fluids can readily flow to the well bore.
`In wells penetrating mediumpermeability formations. and
`particularly those which are completed open hole. it is often
`desirable to create fractures in the fomtations near the well
`bores in order to improve hydrocarbon production from the
`formations. As mentioned above. to create such fractures in
`formations penetrated by cased or open hole well bores
`conventionally. a sealing mechanism such as one or more
`packers must be utilized to isolate the portion of the sub-
`terranean formation to be fractured. When used in open hole
`well bores. such sealing mechanisms are often incapable of
`containing the fracturing fluid utilized at the required frac-
`turing pressure. Even when the sealing mechanisms are
`capable of isolating a formation to be fractured penetrated
`by either a cased or open hole well bore.
`the use and
`installation of the sealing mechanisms are time consuming
`and add considerable expense to the fracturing treatment.
`Thus. there is a need for improved methods of creating
`fractures in subterranean formations to improve hydrocar-
`bon production therefrom which are relatively simple and
`inexpensive to perform.
`SUMMARY OF THE INVENTION
`
`The present invention provides improved methods of
`fracturing a subterranean formation penetrated by a well
`bore which do not require the mechanical isolation of the
`formation and meet
`the needs described above. The
`improved methods of this invention basically comprise the
`steps of positioning a hydrajetting tool having at least one
`fluid jet forming nozzle in the well bore adjacent the
`fomration to be fractured. and then jetting fluid through the
`nozzle against the formation at a pressure suflicient to form
`a cavity therein and fracture the formation by stagnation
`pressure in the cavity.
`The jetted fluid can include a particulate propping agent
`which is deposited in the fracture as the jetting pressure of
`the fluid is slowly reduced and the fracture is allowed to
`close. In addition. the fracturing fluid can include one or
`more acids to dissolve formation materials and enlarge the
`formed fracture.
`
`The hydrajetting tool utilized preferably includes a plu-
`rality of fluid jet forming nozzles. Most preferably. the
`nozzles are disposed in a single plane which is aligned with
`the plane of maximum principal stress in the formation to be
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`fractured. Such alignment generally results in the formation
`of a single fracture extending outwardly from and around the
`well bore. When the fluid jet forming nozzles are not aligned
`with the plane of maximum principal stress in the formation.
`each nozzle creates a single fracture.
`The fractures created by the hydrajetting tool can be
`extended further into the formation in accordance with the
`present
`invention by pumping a fluid into the annulus
`between tubing or a work string attached to the hydrajetting
`tool and the well bore to raise the ambient fluid pressure
`exerted on the formation while the formation is being
`fractured by the fluid jets produced by the hydrajetting tool.
`It is. therefore. a general object of the present invention to
`provide improved methods of fracturing subterranean for-
`mations penetrated by well bores.
`Other and further objects. features and advantages of the
`present invention will be readily apparent from the descrip-
`tion of preferred embodiments which follows when taken in
`conjunction with the accompanying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a side elevational View of a hydrajetting tool
`assembly which can be utilized in accordance with the
`present invention.
`FIG. 2 is a side cross sectional partial view of a deviated
`open hole well bore having the hydrajetting tool assembly of
`FIG. 1 along with a conventional centralizer disposed in the
`well bore and connected to a work string.
`FIG. 3 is a side cross sectional view of the deviated well
`bore of FIG. 2 after a plurality of microfractures and
`extended fractures have been created therein in accordance
`with the present invention.
`FIG. 4 is a cross sectional View taken along line 4-4 of
`FIG. 2.
`
`DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`As mentioned above. in wells penetrating medium per-
`meability formations. and particularly deviated wells which
`are completed open hole.
`it
`is often desirable to create
`relatively small fractures referred to in the art as “microf-
`ractures” in the formations near the well bores to improve
`hydrocarbon production therefrom In accordance with the
`present invention. such microfractures are formed in sub-
`terranean well formations utilizing a hydrajetring tool hav-
`ing at least one fluid jet forming nozzle. The tool is posi-
`tioned adjacent to a formation to be fractured. and fluid is
`then jetted through the nozzle against the formation at a
`pressure sutficient to form a cavity therein and fracture the
`formation by stagnation pressure in the cavity. A high
`stagnation pressure is produced at the tip of a cavity in a
`formation being jetted because of the jetted fluids being
`trapped in the cavity as a result of having to flow out of the
`cavity in a direction generally opposite to the direction of the
`incoming jetted fluid. ‘The high pressure exerted on the
`formation at the tip of the cavity causes a microfracture to
`be formed and extended a short distance into the formation.
`In order to extend a microfraeture formed as described
`above further into the formation in accordance with this
`invention. a fluid is pumped from the surface into the well
`bore to raise the ambient fluid pressure exerted on the
`formation while the formation is being fractured by the fluid
`jet or jets produced by the hydrajetting tool. The fluid in the
`well bore flows into the cavity produced by the fluid jet and
`flows into the fracture at a rate and high pressure suflicient
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`to extend the fracture an additional distance from the well
`bore into the formation.
`
`Referring now to FIG. 1. a hydrajetting tool assembly for
`use in accordance with the present invention is illustrated
`and generally designated by the numeral 10. The tool
`assembly 10 is shown threadedly connected to a work string
`12 through which a fluid is pumped at a high pressure. In a
`preferred arrangement as shown in FIG. 1. the tool assembly
`10 is comprised of a tubular hydrajetting tool 14 and a
`tubular. ball activated. check valve member 16.
`
`The hydrajetting tool 14 includes an axial fluid flow
`passageway 18 extending therethrough and communicating
`with at least one and preferably as many as feasible. angu-
`larly spaced lateral ports 20 disposed through the sides of the
`tool 14. A fluid jet forming nozzle 22 is connected within
`each of the ports 20. As will be described further
`hereinbelow. the fluid jet forming nozzles 22 are preferably
`disposed in a single plane which is positioned at a prede-
`terrnined orientation with respect to the longitudinal axis of
`the tool 14. Such orientation of the plane of the nozzles 22
`coincides with the orientation of the plane of maximum
`principal stress in the formation to be fractured relative to
`the longitudinal axis of the well bore penetrating the for-
`mation.
`
`The tubular. ball activated. check valve 16 is threadedly
`connected to the end of the hydrajetting tool 14 opposite
`from the work string 12 and includes a longitudinal flow
`passageway 26 extending therethrough. The longitudinal
`passageway 26 is comprised of a relatively small diameter
`longitudinal bore 24 through the exterior end portion of the
`valve member 16 and a larger diameter counter bore 28
`through the forward portion of the valve member which
`forms an annular seating surface 29 in the valve member for
`receiving a ball 30 (FIG. 1). As will be understood by those
`skilled in the art. prior to when the ball 30 is dropped into
`the tubular check valve member 16 as shown in FIG. 1. fluid
`freely flows through the hydrajetting tool 14 and the check
`valve member 16. After the ball 30 is seated on the seat 29
`in the check valve member 16 as illustrated in FIG. 1. flow
`through the check valve member 16 is terminated which
`causes all of the fluid pumped into the work string 12 and
`into the hydrajetting tool 14 to exit the hydrajetting tool 14
`by way of the fluid jet forming nozzles 22 thereof. When it
`is desired to reverse circulate fluids through the check valve
`member 16. the hydrajetting tool 14 and the work string 12.
`the fluid pressure exerted within the work string 12 is
`reduced whereby higher pressure fluid surrounding the
`hydrajetting tool 14 and check valve member 16 freely flows
`through the check valve member 16. causing the ball 30 to
`be pushed out of engagement with the seat 29. and through
`the nozzles 22 into and through the work string 12.
`Referring now to FIG. 2. a hydrocarbon producing sub-
`terranean formation 40 is illustrated penetrated by a deviated
`open hole well bore 42. The deviated well bore 42 includes
`a substantially vertical portion 44 which extends to the
`surface. and a substantially horizontal portion 46 which
`extends into the formation 40. The work string 12 having the
`tool assembly 10 and an optional conventional centralizer 48
`attached thereto is shown disposed in the well bore 42.
`Prior to running the tool assembly 10, the centralizer 48
`and the work string 12 into the well bore 42. the orientation
`of the plane of maximum principal stress in the formation 40
`to be fractured with respect to the longitudinal direction of
`the well bore 42 is preferably determined utilizing known
`information or conventional and well known techniques and
`tools. Thereafter.
`the hydrajetting tool 14 to be used to
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`perform fractures in the formation 42 is selected having the
`fluid jet forming nozzles 22 disposed in a plane which is
`oriented with respect to the longitudinal axis of the hydra-
`jetting tool 14 in a manner whereby the plane containing the
`fluid jet nozzles 22 can be aligned with the plane of the
`maximum principal stress in the formation 40 when the
`hydrajetting tool 14 is positioned in the well bore 42. As is
`well understood in the art. when the fluid jet forming nozzles
`22 are aligned in the plane of the maximum principal stress
`in the formation 40 to be fractured and a fracture is formed
`therein. a single rnicrofracture extending outwardly from
`and around the well bore 42 in the plane of maximum
`principal stress is formed. Such a single fracture is generally
`preferred in accordance with the present
`invention.
`However. when the fluid jet forming nozzles 22 of the
`hydrajetting tool 14 are not aligned with the plane of
`maximum principal stress in the formation 40. each fluid jet
`forms an individual cavity and fracture in the formation 42
`which in some circumstances may be preferred
`Once the hydrajetting tool assembly 10 has been posi-
`tioned in the well bore 42 adjacent to the formation to be
`fractured 40. a fluid is pumped through the work string 12
`and through the hydrajetting tool assembly 10 whereby the
`fluid flows through the open check valve member 16 and
`circulates tlmough the well bore 42. The circulation is
`preferably continued for a period of time suflicient to clean
`out debris. pipe dope and other materials from inside the
`work string 12 andfrom the well bore 42. Thereafter. the ball
`30 is dropped through the work string 12.
`through the
`hydrajetting tool 14 and into the check valve member 16
`while continuously pumping fluid through the work string
`12 and the hydrajetting tool assembly 10. When the ball 30
`seats on the annular seating surface 29 in the check valve
`member 16 of the assembly 10. all of the fluid is forced
`through the fluid jet forming nozzles 22 of the hydrajetting
`tool 14. The rate of pumping the fluid into the work string
`12 and through the hydrajetting tool 14 is increased to a level
`whereby the pressure of the fluid which is jetted through the
`nozzles 22 reaches that jetting pressure sufflcient to cause
`the creation of the cavities St) and microfractures S2 in the
`subterranean formation 40 as illustrated in FIGS. 2 and 4.
`
`A variety of fluids can be utilized in accordance with the
`present invention for forming fractures including drilling
`fluids and aqueous fluids. Various additives can also be
`included in the fluids utilized such as abrasives. fracture
`propping agent. e.g.. sand. acid to dissolve formation mate-
`rials and other additives lmown to those skilled in the art.
`
`As will be described further hercinbelow. the jet differ-
`ential pressure at which the fluid must be jetted from the
`nozzles 22 of the hydrajetting tool 14 to result in the
`formation of the cavities 50 and microfractures 52 in the
`formation 40 is a pressure of approximately two times the
`pressure required to initiate a fracture in the formation less
`the ambient pressure in the well bore adjacent to the for-
`mation. The pressure required to initiate a fracture in a
`particular formation is dependent upon the particular type of
`rock and/or other mataials forming the fonnation and other
`factors known to those stalled in the art. Generally. after a
`well bore is drilled into a formation. the fracture initiation
`pressure can be determined based on information gained
`during drilling and other known information. Since well
`bores are filled with drilling fluid or other fluid during
`fracture treatments. the ambient pressure in the well bore
`adjacent to the formation being fractured is the hydrostatic
`pressure exmed on the formation by the fluid in the well
`bore. When fluid is pumped into the well bore to increase the
`pressure to a level above hydrostatic to extend the microf-
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`5,765,642
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`5
`ractures as will be described further hereinbelow. the ambi-
`ent pressure is whatever pressure is exerted in the well bore
`on the walls of the formation to be fractured as a result of the
`
`pumping.
`In carrying out the methods of the present invention for
`forming a series of microfractures in a subterranean
`formation. the hydrajetting tool assembly 10 is positioned in
`the well bore 42 adjacent the formation to be fractured as
`shown in FIG. 2. As indicated above. the work suing 12 and
`tool assembly 10 are cleaned by circulating fluid through the
`work string 12 and tool assembly 10 and upwardly through
`the well bore 42 for a period of time. After such circulation.
`the bafl 30 is dropped into the tool assembly 10 and fluid is
`jetted through the nozzles 22 of the hydrajetting tool 14
`against the formation at a pressure suflicient to form a cavity
`therein and fracture the formation by stagnation pressure in
`the cavity. Thereafter. the tool assembly 10 is moved to
`different positions in the formation and the fluid is jetted
`against the formation at those positions whereby successive
`fractures are formed in the formation.
`
`When the well bore 42 is deviated (including horizontal)
`as illustrated in FIG. 2. the oentralizer 48 is utilized with the
`tool assembly 10 to insure that each of the nozzles 22 has a
`proper stand olf clearance from the walls of the well bore 42.
`i.e.. a stand ofl” clearance in the range of from about 1/1 inch
`to about 2 inches.
`At a stand ofi clearance of about 1.5 inches between the
`face of the nozzles 22 and the walls of the well bore and
`when the fluid jets formed flare outwardly at their cores at
`an angle of about 20°. the jet differential pressure required
`to form the cavities S0 and the rnicrofractures 52 is a
`pressure of about 2 times the pressure required to initiate a
`fracture in the formation less the ambient pressure in the
`well bore adjacent to the formation. When the stand oif
`clearance and degree of flare of the fluid jets are dilferent
`from those given above. the following formulas can be
`utilized to calculate the jetting pressure.
`
`Pz'=Pf-1-‘Ia
`
`4’/?i=1.r(d+(s-+o.5)ran{aa:e)]’/4°
`
`wherein;
`Pi=d.ifl’erenoe between formation fracture pressure and
`ambient pressure. psi
`Pf=forrnation fracture pressure. psi
`Ph=ambient pressure. psi
`AP=the jet difierential pressure. psi
`d=diarneter of the jet. inches
`s =stand of clearance. inches
`flare=flaring angle of jet. degrees
`As mentioned above. propping agent is combined with the
`fluid being jetted so that it is carried into the cavities 50 as
`well as at least partially into the microfractures 52 connected
`to the cavities. The propping agent functions to prop open
`the microfracutres 52 when they are closed as a result of the
`termination of the hydrajetting process. In order to insure
`that propping agent remains in the fractures when they close.
`the jetting pressure is preferably slowly reduced to allow the
`fractures to close on propping agent which is held in the
`fractures by the fluid jetting during the closure process. In
`addition to propping the fractures open. the presence of the
`propping agent. e.g.. sand. in the fluid being jetted facilitates
`the cutting and erosion of the formation by the fluid jets. As
`indicated. additional abrasive material can be included in the
`fluid as can one or more acids which react with and dissolve
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`formation materials to enlarge the cavities and fractures as
`they are formed. Once one or more microfractures are
`formed as a result of the above procedure. the hydrajetting
`assembly 10 is moved to a different position and the hydra-
`jetting procedure is repeated to form one or more additional
`microfractures which are spaced a distance from the initial
`rnicrofracture or microfractures.
`As mentioned above. some or all of the rnicrofractures
`produced in a subterranean formation can be extended into
`the formation by pumping a fluid into the well bore to raise
`the ambient pressure therein. That is. in carrying out the
`methods of the present invention to form and extend a
`fracture in the present invention. the hydrajetting assembly
`10 is positioned in the well bore 42 adjacent the formation
`40 to be fractured and fluid is jetted through the nozzles 22
`against the fonrration 40 at a jetting pressure sufficient to
`form the cavities 50 and the microfractures 52. Simulta-
`neously with the hydrajetting of the formation. a fluid is
`pumped into the well bore 42 at a rate to raise the ambient
`pressure in the well bore adjacent the formation to a level
`such that the cavities 50 and microfractnres 52 are enlarged
`and extended whereby enlarged and extended fractures 60
`(FIG. 3) are formed. As shown in FIG. 3. the enlarged and
`extended fractures 60 are preferably formed in spaced
`relationship along the well bore 42 with groups of the
`cavities 50 and microfractures 52 formed therebetween.
`
`EXAMPLE
`
`A deviated well comprised of 12.000 feet of vertical well
`bore containing 7.625 inch casing and 100' of horizontal
`open hole well bore in a hydrocarbon producing formation
`is fractured in accordance with the present invention. The
`fracture initiation pressure of the formation is 9.000 psi and
`the ambient pressure in the well bore adjacent the formation
`is 5765 psi.
`The stand off clearance of the jet forming nozzles of the
`hydrajetting tool used is 1.5 inches and the flare of the jets
`is 2 degrees. The fracturing fluid is a gelled aqueous
`liquid—nitrogen foam having a density of 8.4 lbs/gal. The
`required differential pressure of the jets is calculated to be
`6.740 psi based on two times the formation fracture pressure
`less the hydrostatic pressure [2x(9.000 psi—5.765 psi)=6.740
`psi].
`The formation is fractured using 14.000 feet of 2 inch
`coiled tubing and a 2 inch I.D. hydrajetting tool having three
`angularly spaced 0.1875 inch I.D. jet forming nozzles dis-
`posed in a single plane which is aligned with the plane of
`maximum principal stress in the formation. The average
`surface pumping rate of fracturing fluid utilized is 5.23
`barrels per minute and the average surface pump pressure is
`7.725 psi. In addition. from about 5 to about 10 barrels per
`minute of fluid can be pumped into the annulus between the
`coiled tubing and the well bore to create a larger fracture.
`Thus. the present invention is well adapted to carry out the
`objects and attain the benefits and advantages mentioned as
`well as those which are inherent therein. While numerous
`changes to the apparatus and methods can be made by those
`skilled in the art. such changes are encompassed within the
`spirit of this invention as defined by the appended claims.
`What is claimed is:
`
`1. A method of fracturing a subterranean formation pen-
`etrated by a well bore comprising the steps of:
`(a) positioning a hydrajetting tool having at least one fluid
`jet forming nozzle in said well bore adjacent to said
`formation to be fractured; and
`(b) jetting fluid through said nozzle against said formation
`at a pressure sulficient to form a cavity in the formation
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`that is in fluid communication with the wellbore and
`further jetting fluid through said nozzle to fracture the
`formation by stagnation pressure in the cavity while
`maintaining said fluid communication.
`2. The method of claim 1 wherein the jetting pressure
`utilized in accordance with step (b) is a pressure of about
`two times the pressure required to initiate a fracture in said
`fonnation less the ambient pressure in said well bore adja-
`cent to said formation.
`3. The method of claim 1 which further comprises the step
`of aligning said fluid jet forming nozzle of said tool with the
`plane of maximum principal stress in said formation.
`4. The method of claim 1 wherein said hydrajetting tool
`includes a plurality of fluid jet forming nozzles.
`5. The method of claim 4 wherein said fluid jet forming
`nozzles are disposed in a single plane.
`6. The method of claim 5 which further comprises the step
`of aligning said plane of said fluid jet forming nozzles with
`the plane of maximum principal stress in said formation.
`7. The method of claim 1 wherein said fluid jetted through
`said nozzle contains a particulate propping agent.
`8. The method of claim 7 wherein said propping agent is
`sand.
`
`9. The method of claim 8 which further comprises the step
`of slowly reducing the jetting pressure of said fluid to
`thereby allow said fracture in said formation to close on said
`propping agent.
`10. The method of claim 1 wherein said fluid is an
`
`aqueous fluid.
`11. The method of claim 1 wherein said fluid is an
`aqueous acid solution.
`12. A method of fracturing a subterranean formation
`penetrated by a well bore comprising the steps of:
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`(a) positioning a hydrajetting tool having at least one fluid
`jet forming nozzle in said well bore adjacent to said
`formation to be fractured;
`(b)jet1;ing a fluid through said nozzle against said forma-
`tion at a pressure sulficient to form a fracture in said
`formation; and
`(c) pumping a fluid into said well bore at a rate to raise the
`ambient pres sure in the annulus between said formation
`to a level sufficient to extend said fracture into said
`formation.
`13. The method of claim 12 which further comprises the
`steps of:
`(d) moving said hydrajetting tool to a diflerent position in
`said formation; and
`(e) repeating steps (a) through (c).
`14. The method of claim 12 which further comprises the
`step of aligning said fluidjet forming nozzle of said tool with
`the plane of maximum principal stress in said formation.
`15. The method of claim 12 wherein said hydrajetting tool
`includes a plurality of fluid jet forming nozzles.
`16. The method of claim 15 wherein said fluid jet forming
`nozzles are disposed in a single plane.
`17. The method of claim 16 which further comprises the
`step of aligning said plane of said fluid jet forming nozzles
`with the plane of maximum principal stress in said forma-
`tion.
`18. The method of claim 17 wherein said fluid jetted
`through said nozzle contains a particulate propping agent.
`19. The method of claim 18 wherein said fluid is an
`
`aqueous fluid.
`20. The method of claim 19 wherein said fluid is an
`aqueous acid solution.
`*
`
`*
`
`*
`
`*
`
`*
`
`7
`
`

`
`US005765642C1
`
`(12) EX PARTE REEXAMINATION CERTIFICATE (5516th)
`United States Patent
`
`(10) Number:
`
`US 5,765,642 C1
`(45) Certificate Issued:
`Sep. 19, 2006
`
`Surjaatmadj a
`
`(54) SUBTERRANEAN FORMATION
`FRACTURING METHODS
`
`(56)
`
`References Cited
`PUBLICATIONS
`
`(75)
`
`Inventor:
`
`Jim B. Surjaatmadja, Duncan, OK
`(US)
`
`(73) Assignee: Halliburton Energy Services, Inc.,
`Duncan, OK (US)
`
`Reexamination Request:
`No. 90/007,596, Jun. 20, 2005
`
`Reexamination Certificate for:
`Patent No.:
`5,765,642
`Issued:
`Jun. 16, 1998
`Appl. No.:
`08/774,125
`Filed:
`Dec. 23, 1996
`
`(51)
`
`Int. Cl.
`E21B 43/11
`E21B 43/114
`E21B 43/26
`E21B 43/25
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`
`(52) U.S. Cl.
`
`.................. .. 166/297; 166/177.5; 166/307;
`166/308.1; 166/50; 299/17
`(58) Field of Classification Search ..................... .. None
`See application file for complete search history.
`
`J .B. Surjaatmadja, H.H. Abass and J.L. Brumley, Elimina-
`tion of Near—Wellbore Tortuosities by Means of Hydrojet-
`ting, Society of Petroleum Engineers, SPE 28761—presen-
`tation of the 1994 Asia Pacific Oil & Gas Conference,
`Melbourne, Australia, Nov. 7—10, 1994.
`Robert Wade Brown and Jack L. Loper, Theory of Forma-
`tion Cutting Using the Sand Erosion Process, Society of
`Petroleum Engineers—presented at the 35”’ Armual Fall
`Meeting of SPE, Oct. 2—5, 1960 in Denver, CO.
`H.H. Abass, Saeed Hedayati and D.L. Meadows, Nonplanar
`Fracture Propagation From a Horizontal Wellbore: Experi-
`mental Study, Society of Petroleum Engineers, SPE 24823,
`presented a the 1992 SPE Armual Technical Conference and
`Exhibition held in Washington, D.C., Oct. 4—7, 1992.
`
`Primary Examiner—David O. Reip
`
`(57)
`
`ABSTRACT
`
`Methods of fracturing subterranean formations are provided.
`The methods basically comprise positioning a hydrajetting
`tool having at least one fluid jet forming nozzle in the Well
`bore adjacent the formation to be fractured and jetting fluid
`through the nozzle against
`the formation at a pressure
`sufficient to form a fracture in the formation.
`
`
`
`8
`
`

`
`1
`
`EX PARTE
`
`US 5,765,642 C1
`
`2
`
`As A RESULT OF REEXAMINATION, IT HAS
`
`REEXAMINATION CERTIFICATE
`
`BEEN DETERMINED THAT‘
`
`ISSUED UNDER 35
`NO AMENDMENTS HAVE BEEN MADE TO
`THE PATENT
`
`5
`
`The patentability of claims 1—20 is confirmed.
`
`*
`
`*
`
`*
`
`*
`
`*
`
`9
`
`

`
`US005765642C2
`
`(12) EX PARTE REEXAMINATION CERTIFICATE (837 5th)
`United States Patent
`
`(10) Number:
`
`US 5,765,642 C2
`(45) Certificate Issued:
`Jun. 28, 2011
`
`Surjaatmadja
`
`(75)
`
`(54) SUBTERRANEAN FORMATION
`FRACTURING METHODS
`Inventor:
`Jim B. Surjaatmadja, Duncan, OK
`<US>
`
`.
`.
`.
`(73) Assrgneez Halliburton Energy Services, Inc.,
`D““°a“= OK (US)
`
`_
`_
`ReeXaII11I1atl0I1 Request
`No. 90/010,982, May 6, 2010
`
`Reexamination Certificate for:
`Patent No.:
`5,765,642
`Issued;
`Jun_ 16, 1993
`APP]. NO‘:
`08/774,125
`Filed:
`Dec 23, 1996
`
`Reexamination Certificate C1 5,765,642 issued Sep. 19,
`2006
`
`(51)
`
`Int. Cl.
`E21B 43/11
`E21B 43/114
`E21B 43/26
`E21B 43/25
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`
`(52) U.S. Cl.
`
`..................... .. 166/297; 166/50; 166/177.5;
`166/307; 166/308.1; 299/17
`(58) Field of Classification Search ...................... .. None
`See application file for complete search history.
`
`(56)
`
`References Cited
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`
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`5,765,642 A
`FOREIGN PATENT DOCUMENTS
`
`EP
`EP
`RU
`
`0 427 371 B1
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`SU457792
`
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`
`OTHER PUBLICATIONS
`
`Brown et al., “A New Completion Technique—Sand Ero-
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`the Southern Western District of Production, American
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`
`Ousterhout, R. S., “Field Applications of Abrasive—Jetting
`Techniques,” Journal of Petroleum Technology, May 1961,
`pp. 413—415.
`
`(Continued)
`
`Primary Examiner—Beverly M. Flanagan
`
`(57)
`
`ABSTRACT
`
`Methods of fracturing subterranean formations are provided.
`The methods basically comprise positioning a hydrajetting
`tool having at least one fluid jet forming nozzle in the well
`bore adjacent the formation to be fractured and jetting fluid
`through the nozzle against the formation at a pressure sulfi-
`cient to form a fracture in the formation.
`
`
`
`10
`
`10
`
`

`
`US 5,765,642 C2
`Page 2
`
`OTHER PUBLICATIONS
`
`Pittman, Forrest C., Harriman, Don W., St. John, James C.,
`“Investigation of Abrasive-Laden-Fluid Method For Perfo-
`ration and Fracture Initiation,” Journal of Petroleum Tech-
`nology, May 1961, pp. 489-495.
`. Theory and Practice,”
`.
`Gilbert, Bruce, “The F. I. Process .
`Society of Petroleum Engineers ofAIME, Paper presented at
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`and Petroleum Engineers in Denver, Mar. 3-4, 1958.
`Bucy, B. J., “Deep Penetration Possible With Hydraulic Per-
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`reprinted from Drilling Magazine, Feb. 1960.
`Widden, Martin, “Fluid Mechanics,” Foundations of Engi-
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`stoke, Hampshire, RG21 2XS and London, 1996, pp.
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`
`Forstall, Walton and Gaylord, E.