Correlation Development Between Indentation Parameters and Unaxial Compressive Strength for Colombian Sandstones

Abstract

A new way to characterize the perforated formation strength has been implemented using the Indentation test. This test can be performed on irregular cuttings mounted in acrylic resins forming a disc. The test consists of applying load on each sample by means of a flat end indenter. A graph of the load applied VS penetration of the indenter is developed, and the modules of the test, denominated Indentation Modulus (IM) and Critical Transition Force (CTF) are obtained (Ringstad et al., 1998). Based on the success of previous studies we developed correlations between indentation and mechanical properties for some Colombian sandstones. These correlations were obtained using a set of 248 indentation tests and separate compression tests on parallel sandstone samples from the same depth. This analysis includes Barco Formation, Mirador Formation, and Tambor Formation. For the correlations, IM-UCS and CTF-UCS, the correlation coefficient are 0,81 and 0,70 respectively. The use of the correlation and the Indentation test is helpful for in-situ calibration of the geomechanical models since the indentation test can be performed in real time thus reducing costs and time associated with delayed conventional characterization.

Fundamental Research on Drilling Processes Using Drag Bits

“…However, for small-type drills, when the penetration rate per revolution is less than 0.5 mm/r, feed can be regarded approximately as an indentation. Herein, Mateus's formula [2] is expanded to analyze the cutting forces in feed operation.…”

“…According to Nishimatsu [1], the components of cutting force on the rake surface are (2) where n is the stress distribution coefficient on the failure plane.…”

“…This model consists of a series of successive cycles, each of which comprises a cutting motion and a penetration motion. Nishimatsu's analytical model [1] of rock cutting theories is used to study cutting motions; also, Mateus's formula [2] is used to analyze the cutting forces in feed operation. Finally, laboratory and field experiments are reported to demonstrate the usefulness of the proposed model for investigating relations between UCS and mechanical data.…”

Predicting the strength, density, and porosity of rocks from roll crusher tests

“…Several researchers have tried to estimate rock characteristics using easy and practical methods performed on drilling debris (Santarelli et al, 1996;Ringstad et al, 1998;Uboldi, Civolani, and Zausa, 1999;Schei et al, 2000;Meyers et al, 2005;Mateus et al, 2007;Haftani et al, 2015). The crushability index (CI) test may be an alternative for the estimation of the characteristics of rock from such materials.…”

Estimating the Hardness and Abrasion Properties of Igneous Rocks From Cerchar Indentation Depth (Cid

“…Tercan and Ozcelik [8] investigated the relationships between the mechanical and hardness properties of andesites and their mechanical and abrasion properties and obtained strong correlations. Mateus et al [9] developed correlations between IHI values (248 samples) and mechanical properties of Colombian sandstones. Tumac et al [10] calculated two different SSH values and deformation coefficient (K) for 30 different rocks.…”