Presentation Slides - SPE WA

HM Difficulties with faults SPE 86883• Example problem – only 3 unknowns• 1: Fault throw, 2: good perm 3:low perm (10.4 ft, k1=131.6 mD, k2=1.3mD)• Exact solution prescribed ( via well production only) .• 160K solutions sampled about this exact solution. (“best” = h=31.1 ft, k1=135.9,k2=2.62)• First 3 years of Prod data used to select ‘best’ HM solutions• Conclusion: Unlike most real HM problems this was a “well posed’ Problem YET the best HM solutions generally failed to be goodforecasters• My Conclusion – trying to HM simple models with faults is likely a waste of time unless we have definite data to calibrate NNC’s andtherefore fault throw. ( i.e. we can simulate to high precision but without data to uniquely calibrate – accuracy is poor -> therefore considerwhat extra value is derived by resolving faults.Given the simplicity of the model – and the 160KSample space – the predictive power of the modelIs considered poor-In this case all other inputs fixed/known.- Faulted models “look good” but do not lendthemselves to History matching ( without definitiveconstraining data)CTSOR 39Pty of xx Ltd