Formation Evaluation From Logging on Cuttings

Abstract

Summary This paper presents an overview of a vast research project called Formation Evaluation 2000, which was undertaken by Agip SpA and was aimed at characterizing in real time the formations encountered during drilling by means of measurements on drill chips. To date, the project has demonstrated the feasibility of obtaining representative values of P- and S-wave velocities, rock strength and deformability, permeability, porosity, density, residual fluid con- tent, and saturation. Further work is under way to determine the pore-size distribution, the thermal expansion coefficient, and the electrical resistivity of the rocks from measurements on cuttings. The paper presents the methodology used to systematically develop these technologies and illustrates the results obtained to date during the various sequences of the research, i.e., the primary design of the measurements, laboratory tuning, and field applicability. Furthermore, the paper presents a series of field cases in which these techniques were used, to highlight the industrial applications of such a package of measurements.