測(cè)井資料與應(yīng)用課件

測(cè)井資料與應(yīng)用

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2.5聲波測(cè)井

(AcousticLog)2.5.1測(cè)量原理

*聲波發(fā)生器激發(fā)聲波*聲波沿井壁滑行傳播*兩個(gè)接收探頭記錄聲波全波列信號(hào)*測(cè)量聲波傳播經(jīng)過兩個(gè)接收探頭所用的時(shí)間△t

FullwaveformConventionalacousticlogrecordP(compressional),S(shear)andstoneleywaveformcompressional常規(guī)聲波測(cè)井一般提供聲波時(shí)差ΔtGRΔt不同的地層具有不同的聲波速度和時(shí)差Δt

2.5.3聲波孔隙度通常地層巖石骨架的聲速都遠(yuǎn)大于孔隙中流體的聲速高孔隙地層飽含更多的流體,其聲速將較低

*記錄的總

t=骨架

t

+孔隙流體

t*聲波速度(或Δt)與孔隙度緊密相關(guān)soundsound2.5.4應(yīng)用計(jì)算孔隙度估算地層破裂壓力地層出砂分析計(jì)算滲透率縱合密度測(cè)井資料制作合成地震剖面

Wyllie平均時(shí)間公式(WTA)

最常用的孔隙度公式

:

?s=

式中,△tma

純地層骨架的聲波時(shí)差;

△tf

孔隙流體的聲波時(shí)差;Cp

壓實(shí)校正系數(shù).

Cp(△tf

△tma

)

(△tc

△tma

)壓實(shí)校正固結(jié)不好(欠壓實(shí))的砂巖

Δt較高,用其計(jì)算的孔隙度偏高(≈28-50%),通常需進(jìn)行壓實(shí)校正壓實(shí)校正公式:

致密地層Cp=1固結(jié)不好(欠壓實(shí))地層

壓實(shí)系數(shù)Cp≈0.8–1.3壓實(shí)校正圖版

范例

砂巖Δt=110μs/ft

不校正:

Φ=40%

選擇Cp=1.5:

Φ

≈27%

泥質(zhì)影響校正固結(jié)好(壓實(shí))紗巖:固結(jié)差(非壓實(shí))紗巖:簡(jiǎn)單公式:

油,氣影響校正

油,氣的

t大于水---油/氣層處理出的

ΦA(chǔ)C

偏大油,氣影響校正系數(shù):

氣層

Φt=0.7×ΦA(chǔ)C

油層

Φt=0.9×ΦA(chǔ)C

GRCleansandcleansand:

Δtlog

≈125μs/ft

Δtm≈55.5μs/ft

Δtf≈189μs/ftCp=1.2Vsh≈0.1(10%)

Φ

≈(125-55.5)/(189-55.50)/1.2–Vsh

≈69.5/133.5/1.2–0.1

≈0.43-0.1

≈0.33(%)Usecrossplot:Φ

≈0.3%

Φ

calculation

UsingacousticdataalongΔtΦ研究巖石的物理特性*可用AC資料計(jì)算出許多巖石的彈性摸量參數(shù)*著些彈性摸量參數(shù)可用來評(píng)價(jià)儲(chǔ)層壓裂,出砂等問題BoreholeBreakoutGoodBorehole井壁穩(wěn)定性分析地層出砂分析

SandingPotentialPrediction用斯通利波計(jì)算滲透率*Permeabilityisaimportantparameterforreservoirevaluation*Permeabilityisdifficulttocalculatedaccurately*Stoneleywavecanbeusedtocalculatepermeabilitymoreaccurately

合成地震剖面2.6電阻率測(cè)井AMN0測(cè)量間距電源電壓表B測(cè)井儀器電場(chǎng)電阻率測(cè)井示意圖不同地層的電阻率

松軟地層(泥質(zhì)砂巖)0.5ohmm-50ohmm.致密地層(碳酸巖)10ohmmto1000ohmm.

噴發(fā)巖(硬石膏)可高達(dá)幾千到上萬ohmmPresentationLinearscalelogarithmicscaleSandscale:0.02-200Limestonescale:2-20002.6.3DualLateralResistivityToolInvestigatedepth--deeplogRD80in--shallowlogRS60inUsedtocalculatetrueformationRt&SW

ReceiverGroundloopTransmitter2.6.4InductionToolSchematicConductivitylogInvestigatedepth--deeplogRD60in--shallowlogRS40inUsedtocalculatetrueformationRt&SW

*8Rtcurveswithdifferentinvestigationdepth(10–120in)*Theloggingcurvesseparateinthepermeablezone.*Theinvasionprofileshowsustheflushedzone,transitionzoneandvirginzone.HDIL

(highresolutiondigitalinductionlog)Usefocusedcurrent

*Veryshallow

investigation(2-12in)

*MeasureRtof

flushedzone(RXO)

*Usedforevaluation

ofinvadedaffection

2.6.5聚焦及微電阻率測(cè)井

2.6.6環(huán)境影響InvadedzoneNoneinvadedzone

泥漿侵入對(duì)地層的污染在泥漿侵入條件下的測(cè)井響應(yīng)

主要的環(huán)境影響

●井眼垮塌●電阻率差異大的圍巖

●泥漿侵入.TheaffectionofbedthicknessLogpg7-4,fig7-5LowerRtofsurroundingbedHighRtofsurroundingbedBedthickness

Correction(Inductionlog)Bedthickness>6ftNocorrectionThinnerbedsneedmorecorrectionDifferentRsneeddifferentcorrectionChartforboreholecorrectiontoduallateral

Example

give:

Rm=1?m

RD=10?m

borehole=11in

RLLDcorr

≈10×1.4

≈14(?m)

Waterzone

Saltymud(Rm<Rw,lowRt

invaded):

Ra>Rxo>Rm

Freshwatermud(Rm>Rw,

highRtinvaded):

Ra<Rxo<Rm

Oilzone

Saltymud(Rm<Rw,lowRt

invaded):

Ra>Rxo>Rm

Freshwatermud(Rm>Rw,

highRtinvaded):

Ra>Rxo>Rm

Ra–apparentlogresistivity

Rxo–flushedzoneresistivity

Rm–mudresistivity

InvasionaffectionLowresistivityinvadedHighresistivityinvadedHighresistivityinvasion

Rw=0.04?m/29?CRmf=1.16?m/28.5?CRt(shallower)>Rt(deeper).Lowresistivityinvasion

Rw=1.14?m/30?CRmf=0.16?m/27.8?C