Integrated Workflow for Rock Compressibility Modeling and Analysis of Laboratory Core Data

Abstract

Summary This paper gives several examples of rock compressibility laboratory testing results, and how these data are prepared as input to reservoir simulation or other applications. The final selection of rock compressibility is also compared with standard industry correlations to gauge the accuracy of such correlations in case laboratory results are not available. A review of rock compressibility formulations and associated models is given first, including the treatment of various rock types. Second, laboratory experiments are described using the rock compressibility system (RCS) and the compressibility measurement system (CMS), and a comparison of the two is given. Based on a literature review, there is apparently no available procedure or workflow for analyzing raw compressibility data to derive meaningful interpretations, which are furthermore used in various applications. Taking the results from laboratory testing, a workflow procedure for deriving compressibility input data is outlined in detail, including the choice of ancillary data, for example, Poisson’s ratio. The workflow includes finding regression-based functions of measured pore volumes (PVs), obtaining their derivatives, and finding optimal solutions following a statistical analysis. The demonstrated workflow has been developed to be able to treat alternative laboratory experiments and results for a variety of rock types in carbonates, with regression-based compressibility correlations found. This allows safeguard against possible shortcomings and pitfalls, which are also demonstrated. Having been implemented on real case studies, the formulation presented has been computerized, allowing for ease of data handling, comparative study, and consistency.