аЯрЁБс>ўџ )ўџџџўџџџ*џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџ l ЩсСПРт\pThe Free Software Foundation Bфœ=PF0*8X@"Зк1Д Helvetica1ДCourier1Д Courier New1ДМ Courier New1Д Helvetica$#,##0_);($#,##0)$#,##0_);[Red]($#,##0)$#,##0.00_);($#,##0.00)$#,##0.00_);[Red]($#,##0.00)-**_($* #,##0_);_($* (#,##0);_($* "-"_);_(@_)*)'_(* #,##0_);_(* (#,##0);_(* "-"_);_(@_)5,2_($* #,##0.00_);_($* (#,##0.00);_($* "-"??_);_(@_)2+/_(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(@_)2$#,##0.00;[Red]$#,##0.003$#,##0.00;[Red]($#,##0.00)4$#,##0;[Red]($#,##00)50.00%;[Red](0.00%)6 0%;[Red](0%)7#,##0.00;[Red](#,##0.00)8#,##0;[Red](#,##0)рѕџ Р рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР рѕџ єР р Р р+ѕџ јР р)ѕџ јР р,ѕџ јР р*ѕџ јР р ѕџ јР р аˆ ~~Пр иˆ ~~Пр#иˆ ~~Пр иˆ ~~Пр7#мˆ ~~Пр8#мˆ ~~П“€џ“€џ“€џ“€џ“€џ“€џ’т8џџџџџџџџџџџџ€€€€€€€€€РРР€€€™™џ™3fџџЬЬџџffџ€€fЬЬЬџ€џџџџџџ€€€€€џЬџЬџџЬџЬџџ™™Ьџџ™ЬЬ™џџЬ™3fџ3ЬЬ™ЬџЬџ™џfff™–––3f3™f333™3™3f33™ЧЧЧ…&HSECURITIES AND EXCHANGE COMMISS…&^ SECURITIES AND EXCHANGE COM (1)…&SECURITIES AND EXCHANGE COM (2)…дJ SIGNATURE l Щ н  dќЉёвMbP?_*+‚€%џРŒ,Сƒ„&Тй­e2й?'Тй­e2й?(Тй­e2й?)Тй­e2й?Ё",D/р?р?ф!SECURITIES AND EXCHANGE COM (1)!SECURITIES AND EXCHANGE COM (2) SIGNATUREU } †} m ссссссссс с с с сссс'WELLINGTON MANAGEMENT GROUP LLPSC 13G/A 02/14/2013*"SECURITIES AND EXCHANGE COMMISSION [X]Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] Rule 13d-1(d)  $____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/з$,еџСџЋџŸџqџeџYџMџ%џ§ўеўЩўНў•ў=PF0*8X> Ж@х l Щ /ЮH dќЉёвMbP?_*+‚€%џРŒ,Сƒ„&Тй­e2й?'Тй­e2й?(Тй­e2й?)Тй­e2й?Ё",D/р?р?ф!SECURITIES AND EXCHANGE COMMISS!SECURITIES AND EXCHANGE COM (2) SIGNATUREU } У} $ } !} y /ссссссссс с с с сссссссссссссссссссс'WELLINGTON MANAGEMENT GROUP LLPSC 13G/A 02/14/2013*"SECURITIES AND EXCHANGE COMMISSION~ "NAMES OF REPORTING PERSONS 2 *I.R.S. 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"[ ]~ #..#&PERCENT OF CLASS REPRESENTED BY AMOUNT$$ IN ROW (9)%%&&4.05%~ '2 'TYPE OF REPORTING PERSON(() )IA*+$,____________________________1-)Created by Morningstar Document Research.0.(http://documentresearch.morningstar.com/з"2бџЙџžџ^џ<џ$џџеўНўЃў—ў‹ўcў=PF0*8X> Ж@хт..--,,))''&&$$##""     l Щ  ‚ы$”1=>FG dќЉёвMbP?_*+‚€%џРŒ,Сƒ„&Тй­e2й?'Тй­e2й?(Тй­e2й?)Тй­e2й?Ё",D/р?р?ф!SECURITIES AND EXCHANGE COMMISS!SECURITIES AND EXCHANGE COM (1) SIGNATUREU } I"} †} ч} y<} y ‚ссссссссс с с с сссссссссссссссссссс'WELLINGTON MANAGEMENT GROUP LLPSC 13G/A 02/14/2013*"SECURITIES AND EXCHANGE COMMISSION Item 1.  (a) Name of Issuer  ) !Pioneer Natural Resources Company  (b)/ 'Address of Issuer's Principal Executive   Offices 200 Williams Square West$5205 North Oconnor BoulevardIrving, TX 75039# Item 2. (a)Name of Person Filing80Wellington Management Company, LLP (''WellingtonManagement'') (b)0(Address of Principal Business Office or,if None, Residence280 Congress StreetBoston, MA 02210 (c) CitizenshipMassachusetts (d)$Title of Class of Securities Common Stock (e) CUSIP Number€Б’ХA# Item 3..&If This Statement is Filed Pursuant to0(Rule 13d-1(b), or 13d-2(b) or (c), CheckзD›lеџСџЋџŸџqџeџYџMџ,џїўВўdў9ў§§Н§‰§b§&§вќЁќRќќхћБћћNћ ћлњЈњ~њ с!с"с#с$с%с&с'с(с)с*с+с,с-с.с/с0с1с2с3с4с5с6с7с8с9с:с;с<с=с>с?с ' Whether the Person Filing is a:! !(a) ![ ]1!)Broker or dealer registered under Section"""&"15 of the Act (15 U.S.C. 78o).# #(b) #[ ]1#)Bank as defined in Section 3(a)(6) of the$$$$Act (15 U.S.C. 78c).% %(c) %[ ]/%'Insurance Company as defined in Section&&&,&$3(a)(19) of the Act (15 U.S.C. 78c).' '(d) '[ ]+'#Investment Company registered under(((/('Section 8 of the Investment Company Act)))")of 1940 (15 U.S.C. 80a-8).* *(e) *[X]0*(An investment adviser in accordance with+++$+Rule 240.13d-1(b)(1)(ii)(E);, ,(f) ,[ ]2,*An employee benefit plan or endowment fund---7-/in accordance with Rule 240.13d-1(b)(1)(ii)(F);. .(g) .[ ]2.*A parent holding company or control person///7//in accordance with Rule 240.13d-1(b)(1)(ii)(G);0 0(h) 0[ ]30+A savings association as defined in Section11111)3(b) of the Federal Deposit Insurance Act2222(12 U.S.C. 1813);3 3(i) 3[ ]/3'A church plan that is excluded from the44414)definition of an investment company under55525*Section 3(c)(14) of the Investment Company666&6Act of 1940 (15 U.S.C. 80a-3);7 7(j) 7[ ]>76Group, in accordance with Rule 240.13d-1(b)(1)(ii)(J).8838+If this statement is filed pursuant to Rule99$913d-1(c), check this box [ ]: Item 4.: Ownership.3;+Provide the following information regarding.<&the aggregate number and percentage of8=0the class of securities of the issuer identified> in Item 1.? ?(a)"?Amount Beneficially Owned:зDa lЩџjџџНўyўўШ§o§§Юќpќ$ќФћeћћІњEњьљЋљNљѕј›јMјсї’їRїїфіВіvі@сAсBсCсDсEсFсGсHсIсJсKсLсMсNсOсPсQсRсSсTсUсVсWсXсYсZс[с\с]с^с_с@.@&Wellington Management, in its capacityAA/A'as investment adviser, may be deemed toBB0B(beneficially own 4,993,305 shares of theCC2C*Issuer which are held of record by clientsDD!Dof Wellington Management.E E(b)EPercent of Class:FF4.05%G G(c)0G(Number of shares as to which such personHH Hhas:I I(i)0I(sole power to vote or to direct the vote~ IJ J(ii)2J*shared power to vote or to direct the vote~ JвЩМKK(iii):K2sole power to dispose or to direct the disposition~ KLLL LofM M(iv)0M(shared power to dispose or to direct the~ MfФ0NNNNdisposition ofO Item 5.3O+Ownership of Five Percent or Less of Class.P2P*If this statement is being filed to reportQ9Q1the fact that as of the date hereof the reportingR4R,person has ceased to be the beneficial ownerS1S)of more than five percent of the class ofT,T$securities, check the following: [X]#U Item 6.5U-Ownership of More than Five Percent on BehalfVVof Another Person.W0W(The securities as to which this ScheduleX1X)is filed by Wellington Management, in itsY1Y)capacity as investment adviser, are ownedZ6Z.of record by clients of Wellington Management.[0[(Those clients have the right to receive,\8\0or the power to direct the receipt of, dividends]4],from, or the proceeds from the sale of, such^3^+securities. No such client is known to have_0_(such right or power with respect to moreзD% lТџwџ+џнў ўhўKўќ§д§w§§Ўќ|ќќрћˆћFћ§њЙњxњ<њмљВљrљ1љ№јЊјjј"јої`сaсbсcсdсeсfсgсhсiсjсkсlсmсnсoсpсqсrсsсtсuсvсwсxсyсzс{с|с}с~сс`6`.than five percent of this class of securities,aaexcept as follows:bbccNot Applicable.#d Item 7.,d$Identification and Classification ofe2e*the Subsidiary Which Acquired the Securityf/f'Being Reported on by the Parent HoldingggCompany.hhNot Applicable.#i Item 8.,i$Identification and Classification ofjjMembers of the Group.kkllNot Applicable.#m Item 9.'mNotice of Dissolution of Group.nnooNot Applicable.$p Item 10.pCertification.qqr4r,By signing below I certify that, to the bests2s*of my knowledge and belief, the securitiest/t'referred to above were acquired and areu/u'held in the ordinary course of businessv2v*and were not acquired and are not held forw5w-the purpose of or with the effect of changingx0x(or influencing the control of the issuery/y'of the securities and were not acquiredz1z)and are not held in connection with or as{/{'a participant in any transaction having||that purpose or effect.}~$____________________________зDѕlКџџxџQџњўИўyўYў2ўл§Ў§–§o§§§оќœќ„ќ@ќўћПћ€ћ>ћљњЙњzњ9њњљЫљПљ€сс1€)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/з‘=PF0*8X> Ж@хrn€€||{{zzyyxxwwvvuuttssrrppoommlljjiihhggffeeddccaa``__^^]]\\[[ZZYYXXWWVVUUTTSSRRQQPPOOHHGGFFEEDDCCBBAA@@??>>==<<;;::99887766554433221100//..--,,++**))((''&&%%$$##""!!      l Щ Q dќЉёвMbP?_*+‚€%џРŒ,Сƒ„&Тй­e2й?'Тй­e2й?(Тй­e2й?)Тй­e2й?Ё",D/р?р?ф!SECURITIES AND EXCHANGE COMMISS!SECURITIES AND EXCHANGE COM (1)!SECURITIES AND EXCHANGE COM (2)U } $ } Њ= ссссссссс с с с ссссссссссс'WELLINGTON MANAGEMENT GROUP LLPSC 13G/A 02/14/2013 SIGNATURE!By: /s/ Steven M. 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