Automated Evaluation of Rocks Physical Properties to Enhance Drilling Efficiency and Reduce Non-Productive Time

Abstract

Abstract Evaluating physical properties of rock while drilling can improve and optimize drilling operations and save time and cost of the drilling operation. Logging tools, correlations, mini-frac test, micro-frac test, and coring operations are used to have required parameters of physical properties of rock to have a clear image about features of drilled formation. However, most of them are expensive, consumed time, decelerate wells’ deliveries and have impact of error influence. In this paper, physical properties of rock were calculated by using surface drilling parameters and fluid rheological properties to ensure delivery of wells with efficient drilling operations in optimum time and cost. Surface drilling parameters and fluid rheological properties were collected to evaluate rock physical properties. The drilling parameters and mud rheological properties in certain hole sections were analyzed first to determine the effect of rate of penetration (ROP) and cuttings concentration in annulus (CCA) on physical rock properties of rock. Evaluating physical rock properties while drilling from surface drilling parameters and fluid rheology properties will help and enhance the drilling operations, minimize drilling problems and has a major impact on cost optimization. The data selected are from the same hole size, formation type and mud type. The relationship between collected drilling parameters, fluid rheological properties and physical rock properties were then evaluated to determine the relationships of the correlations strengths. This is the first time to evaluate physical rock properties from drilling surface parameters and fluid rheological properties and showed acceptable calculated values. The results of this work include a developed model of rock bulk density that has been validated and compared with sonic and bulk density logs. The model has shown very low absolute error (less than 2%). Other physical properties of rock were determined based on developed bulk density model by using strong correlations that are applicable for same scenario. Evaluation of physical rock properties in the hole sections was tested and helped estimate bulk density, porosity and Ultimate Compressive Strength (UCS).