Study on array laterolog response simulation and mud-filtrate invasion correction

Abstract

It is a complicated task to evaluate the reservoirs influenced by mud-filtrate invasion. This study presents numerical simulation results of array laterolog response and the approach for mud-filtrate invasion correction. Considering differential equations and boundary conditions of the steady current field in the rock medium, finite element method is utilized to solve the Laplace equation. Then the potential value at each node is calculated along with the apparent resistivity of six measuring modes of array laterolog. Based on the numerical results, the array laterolog response is affected by various parameters including borehole radius, mud-filtrate resistivity, mud-filtrate invasion radius and invaded zone resistivity. Correction charts for borehole and mud-filtrate invasion are developed to accurately obtain the mud-filtrate invasion depth and the true resistivity of the uninvaded formation. The correction chart has been applied to the real array laterolog data of a sandstone reservoir, which the corrected resistivity is closer to the true formation resistivity.

Element‐free Galerkin numerical mode‐matching method for static and time‐harmonic electromagnetic fields in orthogonal‐plano‐cylindrically layered media

“…And the height of the longest A6 with several meters is about 100 times of the monitoring electrode. So the array lateral logging tool is a typical multiscale model, which has five mainly working modes with different radial detection depth, and its working principle can be found in Reference 17. We have verified the efficiency of the method using point sources to simulate a cylindrical electrode in Reference 18.…”

Research and application of high-resolution micro-cylindrically focused logging tool

“…Wash zone resistivity is an essential parameter in petroleum resource exploration and is important for formation evaluation (Tian et al, 2003;Salazar and Torres-Verdin, 2009) Although certain array logging methods, such as array induction (Wang, 2003;Li et al, 2012;Zhou et al, 2016;Bai et al, 2018) and lateral logging (Li et al, 2010;Zhao et al, 2019;Zhu et al, 2019), can detect formation features at different radial depths, their greater detection depths pose difficulties in the accurate evaluation of mudcake and electrical parameters in shallow formations. To finely measure the resistivity of shallow formations, resistivity logging instruments achieve a reduced detection depth by reducing the electrode distance.…”

Preparation and investigation of self-healing gel for mitigating circulation loss

“…It not only consumes a large amount of working fluid loss but also directly causes major economic losses. Lost circulation also increases nonproduction time, prolongs drilling cycle, affects the exploration and development process, and even induces accidents, such as sticking, well collapse and blowout (Mansour et al, 2019;Zhao et al, 2019;Tang et al, 2022). Due to the complex problem of lost circulation, a commonly used method is bridging plugging method; in the method, a certain amount of bridging plugging material is added to the drilling fluid according to the construction situation, and as the drilling fluid enters the lost circulation formation, the plugging layer is formed by filling and stacking to reduce the leakage rate and achieve plugging (Alhaidari et al, 2022).…”