NjordisastructurallycomplexLowerJurassic oilfieldlocated on the HaltenTerrace, offshoremidNorway. The fieldwasdiscovered in1986andhasbeenunderproduction since 1997. The fieldisproduced bya combination ofdepletion andcrestalgasinjection. Difficultiesinfindingneweconomically viabledrillingtargets led to adrillingstop in2001-2002 andproduction isnow indecline.Aseconddrillingphasecomprisingthree infill wells beganinlate2002. Production results from thesethree wells will be criticalfor determiningNjord's futureb eyond2005.Duringthe drillingstop,a dvanced 3Dvisualization techniquesw ereused to unravelt he field's complexextensionalfault pattern. Neww ell targets werei dentified usingmultipleseismic datasets and multipleinterpretations. 3Dvisualization wasalso used duringdrillingto keepthe wells withinthe reservoirand to avoid anunstableformation.Reservoirs imulation models wereused to identifyareasw ithundrained potential,a nd4 Dseismic data indicated fault blockswherechangesingassaturation had occurred.The reservoiroilisinitially under-saturated, but gashasalso comeout ofsolution inareaswithsignificant pressuredepletion. Gashasalso beenre-injected. Newwells wereplanned to avoid thesefault blocks. Targetpoints wereplaced using3Dvisualization software andwell pathd og-leg anglesw erec alculated.The process continued iteratively untilawell pathh ad been achieved withmaximum reservoirp enetration andrealistic dog-leg angles( , 3.5 8 ). Realt imed atawere transmitted to shored uringd rillingusingaweb service.Thesed atai ncluded survey,petrophysicall og, biostratigraphicalandboreholeimage datathatwereused alongside the 3Dvisualizations.Inthisway,drilling progress through the G&G interpretation wascontinuouslymonitored.Similarly,geosteering, or plugback and sidetrack, decisionsw erequickly evaluated.