Synthetic focusing and simulation of dual laterolog tool in axisymmetric subsurface models

Compensation effect analysis in DIE method for through-casing measuring formation resistivity

“…Simulation of TCR measurements via numerical methods is rather challenging due to the high electrical conductivity contrast and small thickness of casing (Chen et al, 2010;Chen et al, 2011;Cozzolino and da Silva, 2007;Han et al, 2009;Kozhevnikov and Antonov, 2008;Martinez et al, 2010;Nam, 2010;Yegireddi and Bhaskar, 2009). Here, we utilize a 2D axially symmetric numerical method based on a selfadaptive goal oriented hp-finite-element method (FEM) that accurately simulates such logging measurements.…”

Assessment of Delaware and Groningen effects on dual-laterolog measurements with a self-adaptive hp finite-element method

“…In LLd mode, all bucking current electrodes inject current and all of the injected currents return to the current-return electrode ͑B͒ at the earth's surface, which can be easily 2 to 3 km apart from the logging point. The two focusing systems of DLL instruments provide different current paths ͑Figure 1͒ and radial lengths of investigation ͑Anderson, 2001; Cozzolino and Silva, 2007;Nam et al, 2009͒. Service companies have been manufacturing DLL tools to work in slightly different ways, possibly with different focusing ͑or monitoring͒ conditions and different dimensions ͑e.g., Anderson, 2001;Cozzolino and Silva, 2007;Yang et al, 2007;Nam et al, 2009͒. In this study, we implement a specific commercial DLL tool configuration ͑Figure 1͒ whereby we place each simulated electrode at the same location and with the same vertical dimension as that of the commercial DLL tool. We assume that the resistivity of all of the electrodes is 10 ‫5מ‬ ohm-m, whereas the resistivity of the tool's mandrel is 10 5 ohm-m, resulting in a resistivity contrast at the interfaces between electrodes and insulator equal to 10 10 .…”

“…Most DC simulations of DLL measurements reported to date ͑e.g., Liu et al, 1999;Cozzolino and Silva, 2007;Nam et al, 2009͒ assumed the following two operating conditions: ͑1͒ electrode B is at infinity, and ͑2͒ electrode N is at zero potential ͑Anderson, 2001͒. Under extreme logging conditions, these simulation assumptions become inadequate and, hence, fail to simulate Delaware effects accurately.…”

Two dimensional combined inversion of short- and long-normal dc resistivity well log data

“…If the thicknesses are finite then, either the finite element method (FEM, e.g. Cozzolino and da Conceição da Silva, 2007), the finite differences method (FDM, e.g. Roy and Dutta, 1997;Towle et al, 1988), the integral equation method (IEM, e.g.…”