INDUCED POLARIZATION (IP)

- Aug 12, 2019-

Induced Polarization (IP) tau siv ntau xyoo los ntawm Geophysicists hauv kev tshawb nrhiav cov ntxhia thiab dej tso nyiaj. Xyoo tsis ntev los no Induced Polarization kuj tau dhau los ua kev daws teeb meem los nrhiav cov peev txheej ntawm roj av hauv dej. IP yog qhov txiaj ntsig zoo ntawm cov ntaub ntawv hauv kev lag luam hlau lag luam.

IP yog dab tsi?

Hauv cov pob zeb-kua tshuab, lub zog hluav taws xob tuaj yeem khaws cia rau lub sijhawm luv. Ib qho tam sim no siv tau yuav ua rau lub tshuab hluav taws xob me me uas txiav tawm nrog lub sijhawm tom qab hloov tam sim no. Induced polarization yog ntau tshaj hais nyob rau hauv mineralized pob zeb.

Induced Polarization yog cov khoom siv ntawm geophysical ntawm cov qauv tsim nyob hauv lub ntiaj teb uas ua rau tau txais hluav taws xob xwm txheej kom muaj cov hluav taws xob tsis tshua muaj hluav taws xob ntev dua li qhov xav tias yuav hloov tam sim ntawd los ntawm ib qho hluav taws xob mus rau lwm qhov. Muaj ntau lub tswv yim siv los piav txog qhov pom meej ntawm “lub luag haujlwm hauv lub ntiaj teb” no. Ntau cov ntaub ntawv tau sau nyob rau hauv qhov tseeb tias dej muaj nyob hauv qhov chaw txiav tawm ntawm cov pob zeb tsim cov qauv ua piv txwv "IP IP".

Kev tswj hwm txoj cai yog suav tias yog qhov cuam tshuam ntawm kev cuam tshuam ntawm cov hluav taws xob ionic thiab kev siv hluav taws xob (electrode polarization) thiab kom muaj qhov tsis sib xws ntawm ionic thauj khoom (membrane polarization). Sulphide minerals thiab graphite yog qhov chaw ntawm electrode polarization thiab av nplaum thiab zeolites yog qhov chaw ntawm membrane polarization.

Lub hauv paus pib yuam kev tseem ceeb yog qhov tseem ceeb rau kev txiav ntoo thiab cov npoo av ntawm ob sab. Qhov kev ntsuas polarization tuaj yeem tshawb pom qhov muaj cov xaim hluav taws xob txawm tias qhov kev txiav txim siab tsawg dua 1 feem pua. Hauv qhov ntsuas resistivity IP qee zaum pom tau tias yog kev cuam tshuam nrog lwm tus. Kev ntsuas thev naus laus zis ua rau ntawm ib qho zaus yuav txawv ntawm resistivity ntsuas ua nyob rau lwm zaus tshwj tsis yog lawv kho rau cov nyhuv ntawm polarization. Cov nyhuv ua tau zoo nyob rau zaus zaus IP qhov feem pua qhov ntsuas feem pua raug ntsuas.

TUS IP ZOO LI CAS?

Nws yog qhov paub zoo tias… "Ions yog cov nqa khoom ntawm hluav taws xob tam sim no hauv cov kua." Nws tseem paub zoo tias hluav taws xob conductivity hauv cov ntxhia cov kabmob pob zeb tsim cov khoom yog lub luag haujlwm loj dua IP nyhuv. Vim tias nws siv sijhawm rau ions txav mus rau hauv cov kua, ib qho "ncua kev cia" tshwm sim thaum hluav taws xob siv rau qhov tsim muaj kua nyob hauv nws qhov chaw pore. Thaum twg qhov hluav taws xob siv, thiab dheev tawm, lub sijhawm ua hluav taws xob voltage pom kev tsis zoo. Qhov ua tau zoo yog tias thaum lub xaim hluav taws xob tau raug tshem tawm, ib qho kev hloov zuj zus mus rau qhov hloov qis thaum tseem muaj. Lub sijhawm cuam tshuam txog lub sijhawm no tau hu ua "Lub Sij Hawm Rau Sijhawm" IP.

LUB SIJ HAWM TXHUA MEAS:

IP COJ THIAB PERCENT IP:

Txoj kev yooj yim tshaj plaws ntawm kev ntsuas tus IP nyhuv hauv lub sijhawm tus IP yog kev sib piv ntawm qhov ntsuas hluav taws xob qhov hluav taws xob thaum lub sij hawm (t) tom qab cov tshuab hluav taws xob voltage txiav tawm v (t) mus rau qhov hluav taws xob tsis xwm yeem (vc). Qhov tshwm sim yog muab cov lus millivolts toj ib volt lossis feem pua IP.

IP nyhuv = V (t) / Vc feem pua IP = 100 V (t) / Vc

HNUB KAWG INTEGRAL:

Thaum muaj peev xwm muab tso ua ke nyob rau lub sij hawm hloov pauv ntawm lub sij hawm lwj, qhov tau txais cov sij hawm lwj.

CIM:

Lub txim tau sib tw (M) yog txhais raws li: M = 1 / vc x sib ntawm t1 txog t2 xv (t) x dt

Qhov tshwm sim uas lav them yog qhia hauv milliseconds.

COV LAG LUAM YOOJ YIM IP:

Thaum hloov cov tam sim no ntawm ob lossis ntau zaus zaus siv rau kev tsim, qhov cuam tshuam IP zaus IP pom. IP cov txiaj ntsig ntsig txog qhov zaus raug xa mus rau raws li "Cov Zaus Sij Hawm" IP. Thaj resistivity (ra) ntawm ob zaus (rdc) thiab (rac) siv nyob rau hauv lub ntsiab txhais ntawm cov hauj lwm zaus (Fe).

Fe = (rdc-rac) / rac = (rdc / rac) - 1

Feem Feem Ua Feem Ntau (PFE):

PFE = 100 (rdc-rac) / rac