Routine (RCA) and special (SCAL) core analysis tests provide the only direct and quantitative measurement of reservoir petrophysical properties and should provide the foundation for integrated formation evaluation. Unfortunately, and too frequently, core analysis planning, program design and management are done poorly and the results are often confusing or contradictory, with the result that around 70% of legacy SCAL data are generally unfit for purpose.
Variable data quality, the sensitivity of results to different test methods, and poor reporting standards have all contributed to basic mistakes and poor data quality. However, in too many cases, an inconsistent or inappropriate approach to the design, management and interpretation of the core analysis program has been adopted and exacerbated by the conflicting requests of the end users.
So how do we get better data? Firstly, review legacy data and understand the impact of rarely reported experimental artifacts on fundamental rock property measurements. Can data be corrected or are new tests required? Secondly, a multi-disciplinary core analysis management strategy can deliver high quality data by developing a more effective relationship between stakeholders and the data acquisition laboratory. Improved test and reporting specifications, pro-active test program management which engages both the lab and the end user, and real time quality control enables a more coherent and consistent approach to data acquisition and maximizes value from core analysis investments.
Core analysis has uncertainties which are recognizable and manageable. The one idea that members can take away from this lecture is how a pro-active and integrated management strategy can eliminate data redundancy and reduce uncertainty in reservoir models.
Colin McPhee’s 30 years of industry experience includes petrophysics, core analysis, geomechanics, formation damage and sand management. Currently, McPhee is Principal Petrophysicist for Senergy (GB) Limited in Edinburgh, UK, advising clients on petrophysical and geomechanical aspects of field development, asset evaluation and well construction.
McPhee has managed more than 40 core analysis programs and audited over 20,000 SCAL measurements. His active promotion of closer cooperation between stakeholders and core analysis vendors and his innovative solutions in SCAL data interpretation has ensured that core data are more reliable, robust and representative.
McPhee regularly presents at industry conferences worldwide. He has been a Technical Editor for SPE Formation Evaluation, has authored several technical papers and has taught more than 50 core analysis courses to over 800 industry professionals worldwide. McPhee has a BSc in applied geology from Strathclyde University and a Masters in civil engineering from Glasgow University.