Effective Integration of the Core Analysis and Wireline Datasets-Using a New Core Analysis Data Suite and New Software

摘要

Core analysis information is considered one of therncornerstones of formation evaluation. However, there seems tornbe general consensus that more could be done with it, both inrnthe scope of the petrophysical data obtained and how it isrnused. In recognition of this, a suite of methods have beenrndeveloped that provide a ‘new’ extended core data set, andrnsoftware has been designed expressly for the interpretation ofrncore data.rnHistorically, there has been a gap in the services providedrnby core analysis laboratories. Routine core analysis (RCA)rnprovides core plug measurements such as porosity,rnpermeability, fluid saturations, grain density and whole corerngamma at high sample frequency and low cost. However, thisrndata has limited interpretative potential. On the other hand,rnspecial core analysis (SCAL) provides a range of informationrnwith high interpretative potential, but at a low samplingrnfrequency, primarily due to the cost and extended time framesrnassociated with gathering the data.rnA new data set was designed to compliment the currentrn(RCA) data set, significantly extending its interpretativernpotential. The additional measurements performed are total,rneffective and furnace porosity, capillary pressure versus waterrnsaturation curve, surface area, core plug spectral gamma andrnan extended sample description. This new information fillsrnthe gap that currently exists between RCA and SCAL data, byrnproviding significant interpretative potential at a highrnsampling frequency and in a reasonable time frame.rnThe computation of core-based or core-enhancedrnpetrophysical interpretations has also been hampered by thernlack of software designed expressly for modeling core data.rnMost petrophysical packages are decidedly log-centric, whichrnhas limited the effective integration of core and log data.rnMuch core data processing is performed using spreadsheets,rnwith inherent data integration and transfer limitations. Tornredress the balance, a core interpretation module designed tornhandle both the new data suite and existing core data, has beenrndeveloped within a main-stream log analysis softwarernpackage.rnApplications using the new data suite include calibration ofrnpetrophysical parameters, the estimation of Qv profile fromrnsurface area data, the independent assessment of waterrnsaturation through the reservoir, and the estimation of initialrnreservoir flow properties at production start-up. The finalrnoutcome is that core analysis becomes truly a parallelrnformation evaluation discipline. In order to illustrate the corelogrnintegration capabilities of the package, case studies arernpresented.