?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F387%2F&rft.title=Velocity+Estimation+in+Mixtures+using+Tomography&rft.creator=Cahyono%2C+E.&rft.creator=Hochstenbach%2C+M.&rft.creator=Moienaar%2C+J.&rft.creator=Schilders%2C+W.H.A&rft.creator=Terra%2C+G.M.&rft.subject=Energy+and+utilities&rft.description=In+oil+production+a+lot+of+water+is+usually+pumped+up+together+with+the+oil.+For+many+reasons+the+reduction+of+the+water+production+is+a+very+important+issue.+The+method+presented+in+this+paper+is+meant+to+provide+a+necessary+tool+for+this.+Most+drilling+wells+consist+of+a+network+of+bore+holes.+Some+of+them+may+produce+water%2C+others+oil+or+a+mixture.+At+the+moment+the+net+flow+of+all+bore+holes+together+is+brought+to+the+surface.+It+is+desirable+to+be+able+to+detect+how+much+water+a+specific+bore+hole+contributes.+If+this+amount+surpasses+a+critical+value+one+could+then+consider+to+close+that+bore+hole.+This+leads+to+the+question+how+the+composition+of+the+flow+in+a+pipe+can+be+determined+in+situ.+In+this+paper+we+analyze+how+tomography+techniques%2C+well-known+from+medical+applications%2C+can+be+applied+in+the+case+of+a+bore+hole.+These+techniques+allow+to+measure+instantaneously+the+mass+distribution+over+a+cross+section+of+the+pipe.+For+velocity+estimation%2C+the+idea+is+to+detect+the+mass+distributions+at+two+neighbouring+cross+sections+at+successive+times.+Correlating+the+obtained+time+series%2C+one+might+be+able+to+estimate+the+local+velocity+profile.+The+basic+idea+was+already+mentioned+in+literature+before%2C+but+it+was+believed+that+the+number+of+correlations+to+be+evaluated+is+so+huge%2C+that+the+approach+would+fail+in+practice.+In+this+paper+we+describe+the+mathematical+details+of+the+method+and+conclude+that+the+number+of+time+consuming+calculations+is+not+necessarily+a+limiting+factor.+In+addition%2C+suggestions+are+made+to+facilitate+the+use+of+tomography+for+velocity+estimation.&rft.date=2000&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F387%2F1%2FVelocity-estimation-in-mixtures-using-tomography.pdf&rft.identifier=++Cahyono%2C+E.+and+Hochstenbach%2C+M.+and+Moienaar%2C+J.+and+Schilders%2C+W.H.A+and+Terra%2C+G.M.++(2000)+Velocity+Estimation+in+Mixtures+using+Tomography.++%5BStudy+Group+Report%5D+++++