鄂爾多斯盆地延長組超低滲透砂巖儲層油井產(chǎn)能影響因素分析_圖文

1、2009年5月第24卷第3期西安石油大學(xué)學(xué)報(自然科學(xué)版Journal of Xi an Shiyou University (Natural Science Editi on May 2009Vol .24No .3收稿日期:2009202205基金項目:國家西部開發(fā)科技行動重大攻關(guān)項目(編號:2005BA901A13作者簡介:陳明強(19632,男,博士,教授,主要從事油氣田開發(fā)理論與方法、油氣藏數(shù)值模擬與仿真技術(shù)研究.文章編號:16732064X (20090320038203鄂爾多斯盆地延長組超低滲透砂巖儲層油井產(chǎn)能影響因素分析陳明強1,張志國2,曹寶格1,王奇1,楊青1(1.西安石油

2、大學(xué)石油工程學(xué)院,陜西西安,710065;2.中國石油長慶油田分公司,陜西西安710021摘要:為了準確預(yù)測超低滲透油藏的油井產(chǎn)能,必須認識清楚油井產(chǎn)能的影響因素.根據(jù)鄂爾多斯盆地延長組超低滲透砂巖儲層的油井產(chǎn)能與地層單因素參數(shù)間的相關(guān)性統(tǒng)計分析,影響這類儲層油井產(chǎn)能的因素不僅包含油層厚度和地層滲透率,還包括儲層孔隙性、電性等多個因素.由多參數(shù)確定的油井產(chǎn)能預(yù)測模型將存在更加復(fù)雜的結(jié)構(gòu)表達式,實際產(chǎn)能預(yù)測問題應(yīng)是一個非線性系統(tǒng)問題.關(guān)鍵詞:鄂爾多斯盆地;超低滲透油藏;油井產(chǎn)能;影響因素;非線性系統(tǒng)中圖分類號:TE348文獻標識碼:A 近年來,隨著對鄂爾多斯盆地低滲透油藏勘探開發(fā)的推進,已探明并

3、逐步投入開發(fā)的延長組低滲透和超低滲透砂巖儲層原油儲量已超過10×108t .對這些儲量進行開發(fā)的一個普遍特征是油井產(chǎn)能低,變化范圍大(0.220.0t/d ,產(chǎn)能影響因素復(fù)雜.這不僅是這類儲層本身地質(zhì)和原生條件所決定的123,同時反映這類油藏復(fù)雜的物性非均質(zhì)性對傳統(tǒng)油井產(chǎn)能計算方法的挑戰(zhàn).對于低滲透油藏油井產(chǎn)能的計算,大量基于傳統(tǒng)滲流力學(xué)、低速非達西理論、變形介質(zhì)滲流理論等文獻427已經(jīng)給出理論計算與方法.但在實際應(yīng)用時不僅模型的某些參數(shù)確定十分困難,同時計算結(jié)果與實際情況差距很大;原因就在于這類油藏油井產(chǎn)能影響因素具有更加復(fù)雜的相關(guān)性關(guān)系.為了科學(xué)、經(jīng)濟地開發(fā)這類邊際性油藏,有必要

4、重新認識鄂爾多斯盆地延長組超低滲透砂巖儲層影響油井產(chǎn)能的因素,為進一步建立這類油層油井產(chǎn)能預(yù)測方法提供依據(jù),這也是在油田開發(fā)設(shè)計中準確定位油田建設(shè)生產(chǎn)規(guī)模與合理井網(wǎng)部署的決定因素之一.1影響油井產(chǎn)能的因素分析無論是傳統(tǒng)油井產(chǎn)能計算方法,還是基于低滲透理論建立起來的產(chǎn)能評價公式,確定油井產(chǎn)能的基本參數(shù)關(guān)系有兩類:一是反應(yīng)儲層條件的油層厚度和滲透率,二是生產(chǎn)制度確定的生產(chǎn)壓差和油井完善程度系數(shù).其中,第二類關(guān)系屬非客觀因素,這里不再討論.1.1油層巖、電性單參數(shù)對油井產(chǎn)能的影響華慶地區(qū)長6油藏是鄂爾多斯盆地延長組超低滲透砂巖儲層典型實例之一,油層滲透率為(0.30.6×10-3m 2.在

5、早期近400余口勘探井和評價井中,通過對經(jīng)試油證實的油井進行統(tǒng)計分析,可以得到油層厚度、地層滲透率、電阻率、聲波時差、孔隙陳明強等:鄂爾多斯盆地延長組超低滲透砂巖儲層油井產(chǎn)能影響因素分析 度等單參數(shù)與試油產(chǎn)能間的相關(guān)性分析曲線圖1圖5.結(jié)果表明,整體趨勢表現(xiàn)為油層性質(zhì)單參數(shù)大小與試油產(chǎn)能大小有正相關(guān)關(guān)系,但表征線性相關(guān)性的相關(guān)系數(shù)差異極大,尤其是地層滲透率、孔隙度和聲波時差表現(xiàn)出幾乎沒關(guān)系.這就說明對于非均質(zhì)很強的低滲透油藏來講,油層巖、電性單參數(shù)對油井產(chǎn)能的影響是很弱的.雖然地層電阻率與油井產(chǎn)能具有較好相關(guān)性,但實際上它反映的是:儲層為有效儲層(具有一定有效孔隙度和滲透率條件下,儲層含油性差

6、異對油井產(chǎn)能的影響是多參數(shù)影響的結(jié)果.而相關(guān)性次之的油層厚度,也是先確定為有效含油儲層的基礎(chǔ)上,具有非均質(zhì)物性參數(shù)的油層厚度之總和對油井產(chǎn)能的貢獻. 圖1華慶地區(qū)長6油藏油層厚度與試油產(chǎn)量關(guān)系 圖2華慶地區(qū)長6油藏地層滲透率與試油產(chǎn)量關(guān)系 圖3華慶地區(qū)長6油藏地層電阻率與試油產(chǎn)量關(guān)系圖4華慶地區(qū)長6油藏聲波時差與試油產(chǎn)量關(guān)系圖5華慶地區(qū)長6油藏地層孔隙度與試油產(chǎn)量關(guān)系圖6華慶地區(qū)長6油藏孔隙度與聲波時差關(guān)系1.2儲層單因素間相關(guān)性分析統(tǒng)計分析表明聲波時差與孔隙度有很好的相關(guān)性(圖6,因此,產(chǎn)能預(yù)測可以不考慮聲波時差的影響.進一步統(tǒng)計分析滲透率與孔隙度的相關(guān)性(圖7,雖然二者具有指數(shù)相關(guān)性,但相

7、關(guān)系數(shù)平方為0.5127.因此,對于超低滲透油藏就不能象常規(guī)油藏那樣,產(chǎn)能預(yù)測計算只考慮滲透率,而不考慮孔隙度對產(chǎn)能的影響.在影響低滲透油藏油井產(chǎn)量的主要因素中,電阻率參數(shù)是測井資料綜合解釋中的重要指標之一,同時反映油層性質(zhì)與產(chǎn)能貢獻間的關(guān)系,即電阻率越高,含油性越好.但在產(chǎn)能預(yù)測計算中,要獲取地層電阻率參數(shù)具有困難.經(jīng)統(tǒng)計40余口測井解釋資料和試油產(chǎn)量變化發(fā)現(xiàn),華慶地區(qū)長6油藏不同油層性質(zhì)的儲層對試油產(chǎn)能貢獻可以根據(jù)不同性質(zhì)油93西安石油大學(xué)學(xué)報(自然科學(xué)版層厚度組合產(chǎn)生一個總油層厚度來代替,即H =h 油層+0.3h 致密油層+0.4h 油水同層, 這樣可消除電阻率對油井產(chǎn)能的多重因素影響

8、相關(guān)性,同時也區(qū)別不同性質(zhì)油層厚度對油井產(chǎn)能的貢獻. 圖7華慶地區(qū)長6油藏孔隙度與滲透率關(guān)系1.3油井產(chǎn)能影響因素關(guān)系討論對于超低滲透油藏,任何儲層巖、電、物性單因素都無法直接決定油井產(chǎn)能的大小,但它們的組合確能產(chǎn)生良好的相關(guān)性影響.圖8圖10是沿用傳統(tǒng)產(chǎn)能公式簡單乘積組合得到的相關(guān)性變化結(jié)果.流動系數(shù)(滲透率×厚度與試油產(chǎn)能關(guān)系相關(guān)系數(shù)雖然只有0.3657,但比滲透率或厚度任何單因素與試油產(chǎn)能的相關(guān)性要好.流動系數(shù)再乘孔隙度,將其與試油產(chǎn)能的線性相關(guān)系數(shù)提高到0.4581.再乘 圖8華慶地區(qū)長6油藏流動系數(shù)與試油產(chǎn)能關(guān)系 圖9華慶地區(qū)長6油藏流動系數(shù)×孔隙度與試油產(chǎn)能關(guān)系

9、圖10華慶地區(qū)長6油藏流動系數(shù)×孔隙度×電阻率與試油產(chǎn)能關(guān)系電阻率進一步將線性相關(guān)系數(shù)提高到0.8705;如果乘電阻率的平方,相關(guān)系數(shù)可進一步提高到0.9383.由此可見,超低滲透油藏油井產(chǎn)能影響因素多,而且關(guān)系復(fù)雜.2結(jié)論(1對于鄂爾多斯盆地延長組超低滲透砂巖儲層,決定油井產(chǎn)能的地質(zhì)因素不僅是油層厚度和地層滲透率,還與儲層孔隙度有關(guān),尤其是儲層電阻率是不可忽視的重要因素.(2對于鄂爾多斯盆地延長組超低滲透砂巖儲層,由多參數(shù)確定的油井產(chǎn)能預(yù)測模型存在更加復(fù)雜的結(jié)構(gòu)表達式,實際產(chǎn)能預(yù)測問題應(yīng)是一個非線性系統(tǒng)問題.任何簡單化預(yù)測計算公式都很難獲得準確的產(chǎn)能預(yù)測結(jié)果.參考文獻:1

10、王瑞飛,陳明強.特低滲透砂巖儲層可動流體賦存特征及影響因素J .石油學(xué)報,2008,29(4:5582561.2王瑞飛,陳明強,孫衛(wèi).特低滲透砂巖儲層微觀孔隙結(jié)構(gòu)分類評價J .地球?qū)W報,2008,29(2:2132220.3王瑞飛,陳明強,孫衛(wèi).鄂爾多斯盆地延長組超低滲透砂巖儲層微觀孔隙結(jié)構(gòu)特征研究J .地質(zhì)論評,2008,54(2:2702276.4陳明強,蒲春生.變形介質(zhì)低滲透油井真實產(chǎn)能與壓力特征分析J .西安石油大學(xué)學(xué)報:自然科學(xué)版,2006,21(2:18222.5呂成遠,王建.低滲透砂巖油藏滲流啟動壓力梯度實驗研究J .石油勘探與開發(fā),2002,29(2:86289.6劉建軍,劉先

11、貴.有效壓力變化對低滲透多孔介質(zhì)孔隙度、滲透率的影響J .地質(zhì)力學(xué)學(xué)報,2001,7(1:41244.7宋付權(quán).變形介質(zhì)低滲透油藏的產(chǎn)能分析J .特種油氣藏,2002,9(4:33237.責(zé)任編輯:賀元旦04ti on la w are studied by means of the dis p lace ment experi m ents of l ong cores.It is shown that the m igrati on resistance of the e mulsi on dr op let in the core pore is the cu mulative resu

12、lt of the e mulsi on dr op let p lugging the pore.The m igrati on resistance of large dr op let in por ous mediu m is obvi ously greater than that of little dr op let.The injecti on rate of the e mulsi on has great effect on the m igrati on resist2 ance.Under the conditi on of the dr op let dia mete

13、r matching with the pore dia meter,there is a critical injecti on rate,and the e mulsi on can for m obvi ous p lugging in the core only at the critical injecti on rate.W hen the injecti on rate is l ower than the critical rate,the p lugging can not be f or med because of the seri ous demulsificati o

14、n,and when the injecti on rate is higher than the critical rate,it can als o not be for med because of the emulsi on dr op let breaking.Key words:core dis p lace ment;e mulsi on m igrati on rate;influencing fact or;e mulsi on dr op let dia meter;e mulsi on dr op let concentra2 ti onYAN G D ong2dong1

15、,2,YU E X iang2an1,ZHAN G Ying2chun2,YAN G J ian2yuan2(1.E OR Center,Key Laborat ory of Educati on M inis2 try f or Petr oleu m Engineering,China University of Petr oleu m(Beijing,Beijing102249,China;2.Bohai O ilfield Research I nstitute of Exp l orati on and Devel opment,Tianjin B ranch Company,CNO

16、OC,Tanggu300452,Tianjin,ChinaJXSY U2009V.24N.3p.28230 Effect of ca si n g pressure testi n g on the sea li n g perfor mance of ce m en t shea thAbstract:The m icr o2gap bet w een casing and ce ment sheath generated fr om casing p ressure testing is one of the main reas ons leading t o the decline of

17、 the sealing perfor mance of the ce ment sheath.A quantitative for mula f or calculating of the size of the m icr o2gap is deduced according t o the force model of casing22ce ment sheath,and the fact ors of influencing the size of m icr o2gas are analyzed.The results show that during p ressure testi

18、ng,the size of the m icr o2gap is directly p r oporti onal t o wellhead p ressure,it is negative linear cor2 relati on with the p ressure of the surr ounding r ock and the thickness of cement sheath,it is decreases with the increase of the wall thick2 ness of the casing.The size of m icr o2gap first

19、ly increases and then decreaseswith the increase of Youngs modulus of the ce ment sheath. W hen the Youngs modulus is25GPa,the size of m icr o2gas reaches t o the greatest value.W hen the Youngs modulus is less than25 GPa,the Youngs modulus p lays a more i m portant r ole in reducing the size of the

20、 m icr o2gap.It is suggested that the ce ment st one of the l ower Youngs modulus should be selected when the high2p ressure testing of casing is needed.Key words:well ce menting;casing p ressure testing;annular m icr o2gap;sealing perf or mance of ce ment sheathYAO X iao1,2,ZHOU B ing1,L I M ei2pin

21、g3,LUO X iao1,ZHAN G L iang1,HUA Su2dong1(1.College of Materials Science and Engi2 neering,Nanjing University of Technol ogy,Nanjing210009,J iangsu,China;2.State Key Laborat ory ofM aterials2O riented Che m ical En2 gineering,Nanjing210009,J iangsu,China;3.Downhole Service Company,CNPC Sichuan2Chang

22、qing D rilling&Exp l orati on Cor pora2 ti on,Chengdu610051,Sichuan,ChinaJXSY U2009V.24N.3p.31234Research on plugg i n g wa ter and prof ile con trol technology of Jura ssi c reservo i r of early wa ter breakthrough i n J i yuan O ilf i eld Abstract:For the por ous water breakthr ough of the Jur

23、assic reservoir in the p r ocess of devel opment,and the adap tability of differ2 ent p r ofile contr ol agents is evaluated in laborat ory,a deep composite p r ofile contr ol syste m is selected out.I n the syste m,the p re2 cr osslinked particle p lays the part of deep p r ofile contr ol,it can ef

24、fectively p lug up the big pore channels;ass ociating poly mer weak gel acts the part of p lugging and oil dis p lace ment.The on2site app licati on of this syste m shows that the syste m has a good effect of water p lugging and p r ofile contr ol,and it can meet the need of water p lugging and p r

25、ofile contr ol f or the Jurassic reservoir in J iyuan O ilfield.Key words:J iyuan O ilfield;Jurassic reservoir;water p lugging and p r ofile contr ol;por ous water breakthr ough;p re2cr osslinked parti2 cleZHU Hao2ping,BA I B ao2hong,ZHAN G D ao2fa,MA Hong2xing,K AN G L e,L I U Tao,J I N X iao2hong(

26、No.5Pr oducti on Plant,Chan2 gqing O ilfield Company,Xian710065,Shaanxi,ChinaJXSY U2009V.24N.3p.35237Ana lysis of the factors i n fluenc i n g the o il well producti v ity of the un ltra2low per m eab ility s andstone reservo i r i n Yanchang For ma ti on of O rdos Ba si nAbstract:Thr ough the analy

27、sis and statistics of the correlati on bet w een oil well p r oductivity of the unltra2l ow per meability sand2 st one reservoir in Yanchang For mati on of O rdos Basin and the single2fact or para meters of strata,it is held that the fact ors influencing oil well p r oductivity of the reservoir include not only reservoir thickness and for mati on per meability,but als o reservoir por osity,reservoir e2 lectric p r operty and other ele ments which cant be ignored.So,the oil well p r oductivity f orecast