水平定向鉆孔簡單介紹

HorizontalDirectionalDrilling水平定向鉆孔Introduction導言TheHorizontalDirectionalDrilling(HDD)IndustryhasexperiencedsomuchgrowthinthepasttwodecadesthatHDDhasbecomecommonplaceasamethodofinstallation.水平定向鉆孔(HDD)行業(yè)在經(jīng)歷了過去的二十年多的增長后已經(jīng)作為一種常見的安裝方法.Onesourcereportedthatthenumberofunitsinuseincreasedbymorethanahundredfoldinthedecadefollowing1984.一個消息來源報道,使用的數(shù)量在1984后十年里增加超過了百倍.Thisgrowthhasbeendrivenbythebenefitsofferedtoutilityowners(suchastheeliminationoftrafficdisruptionandminimalsurfacedamage)andbytheingenuityofcontractorsindevelopingthistechnology.這種增長的動力一直來自于給公共事業(yè)所有者帶來的的利益(如消除交通中斷和表面損傷最小化)和承包商在發(fā)展這項技術(shù)的創(chuàng)造力。Todate,HDDpipeengineeringhasfocusedoninstallationtechniques,andrightfullyso.目前為止,水平定向鉆孔管工程的焦點在安裝技術(shù)上，理應(yīng)如此。Inmanycases,thepipeexperiencesitsmaximumlifetimeloadsduringthepullbackoperation.在許多情況下，管道在回調(diào)操作中的試驗其最大生命周期負載。ThepurposeofthischapteristoacquaintthereaderwithsomeoftheimportantconsiderationsinselectingtheproperPEpipe.本章的目的是，讓讀者熟悉在選擇適當?shù)腜E管中的一些重要考慮因素。Properselectionofpipeinvolvesconsiderationnotonlyofinstallationdesignfactorssuchaspullbackforcelimitsandcollapseresistance,butalsoofthelong-termperformanceofthepipeonceinstalledinthebore-hole.選擇適當?shù)墓艿腊ú粌H考慮安裝設(shè)計等因素例如回落力的限制和抗破壞強度，也考慮安裝在鉆成洞中的管道的長期性能。Theinformationhereinisnotall-inclusive;theremaybeparametersnotdiscussedthatwillhavesignificantbearingontheproperengineeringofanapplicationandthepipeselection.這里的信息是不完整的；可能有對適當?shù)墓こ虘?yīng)用和管道選擇有重大的影響的參數(shù)沒有討論。Forspecificprojects,thereaderisadvisedtoconsultwithaqualifiedengineertoevaluatetheprojectandprepareaspecificationincludingrecommendationsfordesignandinstallationandforpipeselection.對特定的項目，建議讀者咨詢有資格的工程師來評估項目并準備一個包括建議設(shè)計和安裝及管道的選擇的說明書。ThereadermayfindadditionaldesignandinstallationinformationinASTMF1962, “StandardGuideforUseofMaxi-HorizontalDirectionalDrillingforPlacementofPEPipeorConduitUnderObstacles,IncludingRiverCrossings,”andintheASCEManualofPractice108,“PipelineDesignforInstallationbyDirectionalDrilling."讀者可能會發(fā)現(xiàn)額外的設(shè)計和安裝信息在ASTM(美國試驗材料學會)F1962,“包括河道穿越的情況下，使用馬克西水平定向鉆進來放置PE管道或在障礙下導管的應(yīng)用標準指南.”,在美國土木工程師協(xié)會手冊的練習108,“使用定向鉆井的管道設(shè)計安裝.”Background背景信息SomeoftheearliestusesoflargediameterPEpipeindirectionaldrillingwereforrivercrossings.一些最早使用大口徑PE管的定向鉆井是為了河流穿越.Thesearemajorengineeringprojectsrequiringthoughtfuldesign,installation,andconstruction,whileofferingtheownerthesecurityofdeepriverbedcoverwithminimumenvironmentaldamageorexposure,andnodisruptionofrivertraffic.這些主要的工程項目需要深思熟慮的設(shè)計、安裝、施工，同時提供保證業(yè)主的深河河床最小的環(huán)境破壞和暴露的安全,不會中斷水上交通。PEpipeissuitedfortheseinstallationsbecauseofitsscratchtoleranceandthefusedjoiningsystemwhichgivesazero-leak-ratejointwithdesigntensilecapacityequaltothatofthepipe.PE管適合這些裝置,由于其劃痕公差和融合加入系統(tǒng)，融合加入系統(tǒng)提供了一個用那種管能夠滿足設(shè)計抗拉能力的零泄漏率接合.Todate,directionaldrillershaveinstalledPEpipeforgas,water, andsewermains;communicationconduits;electricalconduits,andavarietyofchemicallines.到目前為止，定向鉆孔機已經(jīng)安裝了為氣體、水和污水電源的PE管;溝通渠道;電氣導管;和各種化學管道Theseprojectsinvolvednotonlyrivercrossingsbutalsohighwaycrossingsandright-of-waysthroughdevelopedareassoasnottodisturbstreets,driveways,andbusinessentrances.這些項目不僅包括河流穿越也包括公路穿越通過發(fā)達地區(qū),以免損壞街道、車道和商業(yè)入口.PEPipeforHorizontalDirectionalDrilling水平定向鉆進中的PE管道Thischaptergivesinformationonthepipeselectionanddesignprocess.這一節(jié)給了管的選擇和設(shè)計過程的信息.Itisnotintendedtobeaprimerondirectionaldrilling.它并不是意欲成為定向轉(zhuǎn)進中的基礎(chǔ).Thereaderseekingsuchinformationcanrefertothereferencesofthischapter.讀者尋求這樣的信息可以參考本章的引用.Suggesteddocumentsarethe^Mini-HorizontalDirectionalDrillingManual"(1)andthe“HorizontalDirectionalDrillingGoodPracticesGuidelines"(2)publishedbytheNorthAmericanSocietyforTrenchlessTechnology(NASTT).建議文檔是北美的非開挖技術(shù)(NASTT)協(xié)會出版的<<迷你水平定向鉆井手冊>>(1)和<<水平定向鉆好實踐指南〉>(2)。HorizontalDirectionalDrillingProcess水平定向鉆井過程Knowledgeofthedirectionaldrillingprocessbythereaderisassumed,butsomereviewmaybeofvalueinestablishingcommonterminology.讀者的定向鉆井過程的知識是假設(shè)的，但是一些觀點在建立常見術(shù)語中可能是有價值的.Briefly,theHDDprocessbeginswithboringasmall,horizontalhole(pilothole)underthecrossingobstacle(e.g.ahighway)withacontinuousstringofsteeldrillrod.簡單地說,這個水平定向鉆井過程始于用連續(xù)一系列的鋼鉆桿在需要穿越的障礙(如高速公路)下鉆一個小的、水平孔(導孔).Whentheboreheadandrodemergeontheoppositesideofthecrossing,aspecialcutter,calledabackreamer,isattachedandpulledbackthroughthepilothole.當孔頭部和桿出現(xiàn)在穿越物對面，一個稱為背鉸刀的特殊的刀具被系上并通過定位孔拉回。Thereamerboresoutthepilotholesothatthepipecanbepulledthrough.Thepipeisusuallypulledthroughfromthesideofthecrossingoppositethedrillrig.鉸刀鉆出導孔，這樣就可以把管道通過。管道通常是從鉆機相反的面拉出。PilotHole導孔Pilotholereamingisthekeytoasuccessfuldirectionaldrillingproject.鉆導孔是定向鉆井項目成功的關(guān)鍵.ItisasimportanttoanHDDpipelineasbackfillplacementistoanopen-cutpipeline.鉆導孔之于水平定向鉆井的重要性如同回填之于露天管道；Properlytrainedcrewscanmakethedifferencebetweenasuccessfulandanunsuccessfuldrillingprogramforautility.經(jīng)過適當訓練了的人員可以區(qū)分鉆井工程實用的成功與否.Severalinstitutionsprovideoperatortrainingprograms,oneofwhichisUniversityofTexasatArlingtonCenterforUndergroundInfrastructureResearchandEducation(CUIRE).一些機構(gòu)提供操作員培訓計劃,其中一個是德克薩斯大學阿靈頓地下基礎(chǔ)設(shè)施教育研究中心(CUIRE).Drillingthepilotholeestablishesthepathofthedrillrod(“drill-path")andsubsequentlythelocationofthePEpipe.鉆導孔為鉆桿路徑的開端(“鉆路徑”),是隨后的PE管的位置。Typically,thebore-headistrackedelectronicallysoastoguidetheholetoapre-designedconfiguration.通常，孔頭的軌跡引導著洞行成預(yù)先設(shè)計好的布局。Oneofthekeyconsiderationsinthedesignofthedrill-pathiscreatingaslargearadiusofcurvatureaspossiblewithinthelimitsoftheright-of-way,thusminimizingcurvature.在設(shè)計的鉆路徑時一個關(guān)鍵的因素是在通過限制的情況下創(chuàng)造盡可能大的曲率半徑,從而最大限度地減少曲率。Curvatureinducesbendingstressesandincreasesthepullbackloadduetothecapstaneffect.曲率誘發(fā)彎曲應(yīng)力并由于絞盤效應(yīng)而增加了回調(diào)載荷。Thecapstaneffectistheincreaseinfrictionaldragwhenpullingthepipearoundacurveduetoacomponentofthepullingforceactingnormaltothecurvature.絞盤效應(yīng)在當使得拖管環(huán)繞成曲線時，由于在調(diào)節(jié)適應(yīng)正常的曲率下，組件的拉力會增加摩擦阻力.Highertensilestressesreducethepipe'scollapseresistance.Thedrill-pathnormallyhascurvaturealongitsverticalprofile.更高的拉應(yīng)力降低管的抗破壞強度。這個鉆路徑通常有沿其垂直剖面的曲率。Curvaturerequirementsaredependentonsitegeometry(crossinglength,requireddepthtoprovidesafecover,stagingsitelocation,etc.)But,thedegreeofcurvatureislimitedbythebendingradiusofthedrillrodandthepipe.曲率取決于其幾何特性(穿越長度，保證安全表層所需要的深度,測試站點位置，等等)。但是，由于鉆桿和管的彎曲半徑，曲率的程度是有限的。Moreoften,thepermittedbendingradiusofthedrillrodcontrolsthecurvatureandthussignificantbendingstressesdonotoccurinthepipe.更多的時候，鉆桿的許用彎曲半徑控制著曲率，從而使顯著的彎曲應(yīng)力不發(fā)生在管。Thedesignershouldminimizethenumberofcurvesandmaximizetheirradiiofcurvatureintheright-of-waybycarefullychoosingtheentryandexitpoints.設(shè)計師應(yīng)該通過仔細選擇通道的入口點和出口點從而使曲線的數(shù)量最少并使得曲率半徑最大.Thedrillershouldalsoattempttominimizeextraneouscurvatureduetoundulations(dog-legs)fromfrequentovercorrectingalignmentorfromdifferencesinthesoilstrataorcobbles.鉆孔機也應(yīng)該試圖減少因頻繁的自對其的矯正及土層或鵝卵石的不同所帶來的波動(狗腿)引起的外來曲率。PilotHoleReaming鉆導孔TheREAMINGoperationconsistsofusinganappropriatetooltoopenthepilotholetoaslightlylargerdiameterthanthecarrierpipeline.鉸孔的操作包括使用合適的工具來使導孔比載體管道直徑略大一點?Thepercentageoversizedependsonmanyvariablesincludingsoiltypes,soilstability,depth,drillingmud,boreholehydrostaticpressure,etc.超大的百分比取決于許多變量,包括土壤類型、土壤穩(wěn)定性、深度、鉆井泥漿,井中靜水壓力Normalover-sizingmaybefrom1.2to1.5timesthediameterofthecarrierpipe.正常情況下尺寸的可能是輸送管直徑的1.2到1.5倍。Whiletheover-sizingisnecessaryforinsertion,itmeansthattheinsertedpipewillhavetosustainverticalearthpressureswithoutsignificantsidesupportfromthesurroundingsoil.因為這個尺寸是放入管是必須的,它意味著置入管將不得不維持在沒有周圍土壤顯著支持力條件下的地球垂直壓力.Priortopullback,afinalreamingpassisnormallymadeusingthesamesizedreameraswillbeusedwhenthepipeispulledback(swabpass).回調(diào)之前，使用將用于把管拉回來(拖把通過)的相同大小的鉸刀來鉆出最后一個鉸孔.Theswabpasscleanstheborehole,removesremainingfinegravelsorclayclumpsandcancompacttheboreholewalls.拖把的通過能清洗鉆洞,去除剩余的細礫石或粘土塊，可以壓縮井壁。DrillingMud鉆探泥漿Usuallya“drillingmud”suchasfluidbentoniteclayisinjectedintotheboreduringcuttingandreamingtostabilizetheholeandremovesoilcuttings.通常“泥漿”，如流動的膨潤土,在切割和鉆孔過程中會被注入孔中，用來穩(wěn)定鉆洞和移除土壤巖屑.Drillingmudcanbemadefromclayorpolymers.Theprimaryclayfordrillingmudissodiummontmorillonite(bentonite).Properlygroundandrefinedbentoniteisaddedtofreshwatertoproducea“mud."鉆井泥漿由粘土或聚合物制成。用于鉆井泥漿的原始粘土主要是鈉蒙脫石(膨潤土)。恰當?shù)牡难心サ木婆驖櫷猎偬砑有┬迈r水便產(chǎn)生這種“泥”.Themudreducesdrillingtorque,andgivesstabilityandsupporttotheboredhole.Thefluidmusthavesufficientgelstrengthtokeepcuttingssuspendedfortransport,toformafiltercakeontheboreholewallthatcontainsthewaterwithinthedrillingfluid,andtoprovidelubricationbetweenthepipeandtheboreholeonpullback.泥漿降低鉆頭扭矩，并支持和穩(wěn)定鉆孔?流體必須有足夠的凝膠強度保持巖屑懸浮易于運輸，使得在井壁形成包含有鉆井液的濾餅，并提供管和鉆孔之間回落時的潤滑。Drillingfluidsaredesignedtomatchthesoilandcutter.Theyaremonitoredthroughouttheprocesstomakesuretheborestaysopen,pumpsarenotoverworked,andfluidcirculationthroughouttheboreholeismaintained.鉆井液的設(shè)計保持與土壤及銃刀匹配.它們監(jiān)控著整個過程，確保著洞的暢通,水泵沒有過載,和確保流體在整個鉆洞的循環(huán).Lossofcirculationcouldcausealockingupandpossiblyoverstressingofthepipeduringpullback.循環(huán)的不暢可能導致鎖死，并使得在管的回拉中超過許用應(yīng)力.Drillingmudsarethixotropicandthusthickenwhenleftundisturbedafterpullback.鉆井泥漿是觸變的,因此再管道拉回完成被靜置后將變厚實。However,unlesscementitiousagentsareadded,thethickenedmudisnostifferthanverysoftclay.Drillingmudprovideslittletonosoilside-supportforthepipe.然而，除非膠結(jié)劑被加入，增厚的泥漿和非常軟粘土一樣軟.鉆井泥漿沒有提供管道如同環(huán)繞泥土的支持.Pullback拉回裝置Thepullbackoperationinvolvespullingtheentirepipelinelengthinonesegment(usually)backthroughthedrillingmudalongthereamed-holepathway.這個拉回操作涉及沿鉆洞途徑將整個管道一段段的(通常)穿過鉆井泥漿.Properpipehandling,cradling,bendingminimization,surfaceinspection,andfusionweldingproceduresneedtobefollowed.適當?shù)墓艿捞幚怼⒇赘?、使其彎曲最小化，在接下來進行表面檢查和熔焊過程.Axialtensionforcereadings,constantinsertionvelocity,mudflowcirculation/exitrates,andfootagelengthinstalledshouldberecorded.應(yīng)記錄軸向張力讀數(shù)，恒定的嵌入速度、泥漿循環(huán)/放出速率，和已安裝的英尺長度。Thepullbackspeedrangesusuallybetween1to2feetperminute.拉回的速度范圍通常在1-2英尺每分鐘。GeneralGuidelines通用指南Thedesignerwillachievethemostefficientdesignforanapplicationbyconsultingwithanexperiencedcontractorandaqualifiedengineer.設(shè)計師通過咨詢與有經(jīng)驗的承包商和合格的工程師將得到最高效的應(yīng)用設(shè)計?HerearesomegeneralconsiderationsthatmayhelpparticularlyinregardtositelocationforPEpipes:這里有一些通用的考慮，這可能對PE管道的選址有特別的幫助：Selectthecrossingroutetokeepittotheshortestreasonabledistance.選擇合理的穿越路線使它為最短的距離。Findroutesandsiteswherethepipelinecanbeconstructedinonecontinuouslength;oratleastinlongmultiplesegmentsfusedtogetherduringinsertion.2?尋找路線和地點中使管道可整體連續(xù)建設(shè);或至少在嵌入中可以一段段的對接.Althoughcompoundcurveshavebeendone,trytouseasstraightadrillpathaspossible.盡管復(fù)合曲線可以完成，但盡量盡可能的使用直鉆路徑。Avoidentryandexitelevationdifferencesinexcessof50feet;bothpointsshouldbeascloseaspossibletothesameelevation.4?避免進入和退出高程差超過50英尺，這兩點應(yīng)該盡可能接近相同的高度.Locateallburiedstructuresandutilitieswithin10feetofthedrill-pathformini-HDDapplicationsandwithin25feetofthedrill-pathformaxi-HDDapplications.Crossinglinesaretypicallyexposedforexactlocation.5?標記出小型水平定向鉆井鉆路徑周圍10英尺和在大型水平定向鉆井鉆路徑周圍25英尺的的地下建筑物體?交叉的線路要準確的標識出來.6.0bserveandavoidabove-groundstructures,suchaspowerlines,whichmightlimittheheightavailableforconstructionequipment.6?觀察并避免地面上的建筑，比如電線,這可能限制施工設(shè)備的許用高度。TheHDDprocesstakesverylittleworkingspaceversusothermethods.However,actualsitespacevariessomewhatdependinguponthecrossingdistance,pipediameter,andsoiltype.7?水平定向鉆井過程需要很少的工作場地，幾乎用不到其他方法。然而實際的地點場所的變化取決于穿越距離,管直徑和土壤類型。Longcrossingswithlargediameterpipeneedbigger,morepowerfulequipmentanddrillrig.8?大直徑管長距離穿越需要更大、更強的裝備和鉆機。Aspipediameterincreases,largevolumesofdrillingfluidsmustbepumped,requiringmore/largerpumpsandmud-cleaningandstorageequipment.9?隨著管直徑的增加，將需要大量的鉆井液，需要更大的泵和更多的清洗泥漿和存儲設(shè)備。lO.Spacerequirementsformaxi-HDDrigscanrangefroma100feetwideby150feetlongentryplotfora1000ftcrossingupto