Oil-water relative permeability data for reservoir simulation input Part2:Systematic quality assessment and consistency evaluation

Many published results from special core analysis (SCAL) coreflood include unquantified errors and artifact due to rate effect, end effects, capillary heterogeneity and late time regimes influence on derived relative permeability from analytical methods after experiments. Misleading data may cause serious errors in reservoir performance predictions. This paper describes a framework that assemble in systematic workflow an asymptotic method to infer refined relative permeability end points that is reliable and representative as possible for reservoir simulation model input. A stepwise procedure for relative permeability quality control that comprise the following steps. 1. Relative permeability result quality checks 2. Identifying reliable SCAL results 3. Water-oil relative permeability consistency check 4. Diagnoses the general characteristics of water-oil relative permeability curves 5. Assessing the validity and refinement of relative permeability data with a.Odeh’ technique b.Wayne Beeks’ technique c.Jess Stiles’ technique d.Toth’ technique e.Catherine’ technique f. Constrained parameter estimation method g.Coreflood simulation had been constructed for screening, quality assessment, consistency evaluation and selection of acceptable oil-water relative measurement and data sets that are representative and reliable. The approach had been demonstrated with different field and simulation example the refinement techniques of relative permeability data obtained from analytical methods after experiments and accompanying process of Assimilating unsteady state, steady state and centrifuge experiment result to account for different parts of relative permeability curves and saturation range from individual core plug with similar effective petrophysical character and recognize which parts of each data set are reliable and which are invalid; Selecting a practical value of residual oil saturation Sor "cutting-of" from laboratory flooding experiments at some terminal value of injected pore volume for different set of rock type, to reveal representative and reliable input for reservoir simulation model. Given the importance of relative permeability and residual saturations in recovery assessment of a potential reservoir, searching for the most important points on the relative permeability curve still observe the contradictory trends between highly advanced isolated experiments and a real difficulty in obtaining reliable and representative relative permeabilities from most, if not all displacement flood tests due to inherent error in laboratory measurements of steady state and application of the data to reservoir conditions and violations of the underlying assumptions upon which the unsteady state method is based where the effects of capillarity and viscous fingering cannot be suppressed simultaneously. Quantifying and removal of end effect phenomena, dispersing effect of capillary pressure on saturation shock fronts, viscous fingering from laboratory derived relative permeability data become mandatory especially if non-invasive saturation monitoring diagnosis is not available.