Non-destructive techniques for linking methodology of geochemical and mechanical properties of rock samples

Abstract

Inadequate conventional core data, increasing cost of native sampling techniques, economic downturn in the oil sector, sparse distribution of modern well log suites in horizontal wells, and data acquisition challenges are few among the reasons driving innovation in the use of drill cuttings for determining rock properties and adequate characterization of reservoir units. In this paper, we propose a rock strength proxy based on the correlation between rock strength and elemental geochemistry. The technique uses a combination of X-ray fluorescence and rebound impulse hammer measurements to establish links between the geochemical and mechanical properties of the sampled rocks. We identified five chemo-mechanical facies (CMF) that are formation specific. Furthermore, a cross-validation approach was used to build a predictive model based on acquired elemental and impulse hammer measurements. Consequently, the model was used to predict elastic property and results were encouraging with R2 of 0.83, 0.87, and 0.89 for training, validation, and testing respectively. This proposed method was developed using core plugs retrieved from subsurface formations. It will be useful for examples in rapid assessment of drill cuttings for the determination of rock strength, especially where the only available data is elemental geochemical data.