DDI定向井难度系数

DDI定向井难度数1AHD沿井眼位移AHDorAlongHoleDepartureistheofthedisplacementbetweenindividualsurveystations.沿井眼的位移是个测量点位移的总和。ismeasureoftrueinwellessentiallystretchingawellstraight,likea(azimuthonly,notinclination).它是一口井拉伸直线的真实位移的测量，就像一条线（仅是方位而不是井斜的变化）。SoawellwithnoazimuthchangewillhavesurfacetoTDequaltotheAHD.因此一口井如果有方位的变化将是一个面达到总井深，其位移等于沿井眼的位移。wellturninitwillagreaterAHDcomparedtothetodeparture.一口弯曲的井所生的沿井眼位移相对面到D的位移来说要大些。derivedsimplybyusingPythagorastocalculatethedistancebetweenthesurveyandthenthem.这可以用勾股定来计算各点的位移，并汇总。y=northing,x=easting2ERDRatio

水比ExtendedReachDrillingratio:ThisisthetoTVDratio.Essentiallyitgivesthetotaldisplacement(AHD)tothe\verticaldepth.ItcanbeasmeasureoftheDrillingEnvelopeERHorizontalDrilling.水垂比：大位移井的水垂：是沿井眼位移与垂深之比。本质上，它给出了一个总位移与垂深之比。它可以被认为是大位移平井的一种量度标准。3弯曲度isthecumulativedoglegplannedintothewellorforawell,thetotaldoglegchange(positiveaddition)whenadrop.这是对于计划钻口井或已钻井的总狗腿度，甚至当井眼降斜时总的狗腿度变化（正的增加）。Typically,asthelengthofthewellpathincreases,sotoothetortuosity.Actualdrilledtortuosityisoftenhigherthantheplannedwelltortuosity,especiallyinwellswithlongtangentsections,sincetheDLSinthetangentisoftendifficulttomaintainatzero.一般来说，当井轨迹长度增加，弯曲度也增加。实际钻的弯曲度通常比计划的弯曲度要高，特别是长稳斜段，因在稳斜段的狗腿度很难保持0度。Fromaperspective,itrecommendedthattheoveralltortuositybemaintainedbelow0.8degrees/100ftinordertominimizetheriskofthecompletionassemblyhangingupgettingtobottom.从一个总的观点来看荐的井眼弯曲度应保持在0.8度/100英尺以下，1

以减少下入井底整个管柱遇阻下不到底的风险。Increasingtortuosity(inthiscase,localizedtortuosity)mayalsoleadtodownholedrillingtoolssubjectedtohighershocksandthusforfailure.增加的弯曲度（这种情况下，局部的井眼弯曲度）将同样导致井下钻井工具遭受较高的振动，而增加失效的风险4定向钻井难度数DifficultyIndexislevelperformancemeasurebenchmarkdrillingperformance.Itespeciallyusefulwhenusedasanevaluationmethodoncomplexwellprovidesafirstpassevaluationoftherelativedifficultyencountereddrillingadirectionalwell.定向钻井难度系：定向钻井系数是于评定钻井完成情况的高水平方式。当用作复杂几何井眼的评价方式时就变得特别有用。它提供在钻定向井时所遇到的相对难度的评价。ThefollowingguidelinescanbeusedtoclassifywellsbasedDDI:基DDI，以下列准则可用于定向井的分类：DDI<6short,simplewellsorsimpleprofileswithlowtortuosityDDI<6,相对浅的低曲折度的简单剖面的定向井。难度相对低。–6.4ShorterwellswithhightortuosityorlongerwellswithlowtortuosityDDI6.0–6.4浅井有高的曲折度或深井低曲折的向井。难度相对中等。6.8Longwellswithrelativelytortuouspaths.DDI6.4深定向井伴随相高的曲折度轨迹。难度相对较大。Long,tortuouspathswithadegreeofdifficulty.DDI>6.8，深定向伴随高难度的曲折度轨迹。难度大。5