Thick-Walled Cylinder Core Tests with Flushing by Various Fluids: Results and Practical Applications

Abstract

This paper presents the results of studying petrophysical and geomechanical properties of rocks by conducting thick-walled cylinder core tests (TWCT) - triaxial compression with flushing by various fluids. Experiments were carried out for a limited number of core samples from the Ourinskoe Field, which is a part of the Western Siberia oil and gas-bearing basin. In the framework of the study, various core testing schemes were applied, the results of experiments using different fluids for flushing were analyzed, and the optimal testing parameters (including loading rate, washing time, sample relaxation time, etc.) were selected. The result of the research is a detailed analysis of rock fragments removed by different fluids as a result of triaxial compression and subsequent destruction of a thick-walled cylinder. The paper presents the qualitative relations of the particle size distribution on the prevailing deformation patterns (elastic or plastic), analyzes some petrophysical properties of the strata that control the behavior of the system "rocks – fluid", and consider typical scenarios for TWCT experiments. The obtained experimental data served as an important source of additional information for assessing the draw-down pressure that controlled sand inflow into the wellbore, to determine its particle size distribution, as well as to calculate the size of the wire-wrapped filter liner completion for sand preventing.