Interactive software for processing and modeling oil well resistivity logs as part of a two-dimensional interpretation approach

Abstract

Resistivity well logging is widely used to identify reservoir rocks and evaluate their oil potential. However, the integral nature of the rock response to the field excited by the logging tool leads to the fact that the tool signal opposite the target formation is influenced by a well filled with drilling fluid, overlying sediments, drilling fluid filtrate invasion into the formation, etc. Today's widespread methods of resistivity logs interpretation are based on excessive simplifications, which in complex conditions leads to errors in determining the oil saturation coefficient of the target reservoir, costs of testing water-saturated intervals and missing the potentially promising reservoirs. The paper presents the results of developing new interactive software for working with well logging data and geoelectric model of the environment, focused on a 2D approach to interpreting resistivity logs. The use of a 2D axisymmetric geoelectric model of the medium as a base allows one to correctly take into account the above factors when interpreting practical data. Original realization of user interaction with geoelectric model of near-wellbore space takes into account the features of 2D approach to resistivity logs interpretation and provides convenience of work with multilayer models. The computing server AlondraCore integrated with the software supports resistivity logs simulation using two types of forward problem solvers: high-precision finite-element and fast neural network-based ones. The finite-element algorithms provide high log simulation accuracy with the ability to adjust the tool parameters. On the other hand, the neural network-based algorithms provide fast solution of forward problems for common logging tools.