... and defines an electric vector potential function to describe the transient electromagnetic field excited by the electrode. The radial eddy currents and circular magnetic fields in the conductive ring of the Doll formation are analyzed by the retardation potential. According to the reciprocal symmetry...

... tubing. The DEC tool generates a unique compressed-and-focused magnetic field which INTRODUCTION provides increased Signal-to-Noise Ratio (SNR) and employs an array of magnetic sensors to measure the The critical importance of a well implemented well magnetic flux density distributions azimuthally around...

... viscosity within heavy oil or tar formations. Porosity measured by NMR is subject to environmental influences, such as temperature, local magnetic field, mud type, and, in particular, tool motion. Motion causes a plethora of distortions to the data and affects all low-gradient nuclear magnetic resonance...

..., for instance. well logging Thickness forward modeling spwla 60 Artificial Intelligence SSF porosity Hürlimann formation porosity perturbation log analysis approximation sensitivity magnetic field sensitivity function resonance equation Upstream Oil & Gas NMR measurement...

... and high tolerance to tool orientation error result from focusing the static magnetic field within a 90 degree sector. Extremely low coupling between the RF antenna and the borehole allows power consumption to be kept small. This eliminates the need for fluid excluders, even in very saline muds, as well...

.... Modeling & Simulation pulse sequence diffusion coefficient Artificial Intelligence shale geometry Symposium algorithm log analysis Upstream Oil & Gas coefficient magnetic gradient magnetization well logging bulk decay constant magnetic field decay constant rock sample University...

..., along with a new technique for data processing to achieve reliable data while drilling or pulling. This technique accounts for the effects of motion and imperfect RF magnetic field B 1 using simulation of the tool's static magnetic field B 0 and B 1 . The technique is demonstrated using T1 data...

.... log analysis enhanced recovery new borehole transient electromagnetic system mapping transient signal Upstream Oil & Gas Baker Hughes receiver well logging crossover time eddy current magnetic field Modeling & Simulation floodwater front transient electromagnetic system...

... sensitivity spwla 51 well logging accuracy application pixel size Drilling borehole Symposium standoff imaging tool measurement electrode resistivity electrode magnetic field sensor fracture SPWLA51st Annual Logging Symposium, June 19-23, 2010 1 HIGH RESOLUTION ELECTRICAL IMAGING WHILE...

... Intelligence NMR response magnetic field natural language Upstream Oil & Gas Simulation diffusion well logging approximation relaxation pore space mono-mineralic carbonate rock pore size distribution internal gradient gradient log analysis resolution porosity Symposium spwla 50...

... magnetic field Symposium correction Abstract Triaxial accelerometers and magnetometers are used in wireline logging to determine tool orientation and/or well direction. The sensors often require correction for bias. For magnetometers, the biases are thought to come from magnetization...

... was seen as an improvement over the wireline tool run for comparison, resulting in better characterisation of the laminated sand-shale sequences. log analysis resolution well logging total porosity magnetic field hydrocarbon Upstream Oil & Gas porosity spwla 46 Drilling investigation...

.... At every logging depth, 3DEX can acquire nine components of the magnetic field (three main: Hxx, Hyy, Hzz ; and six cross-components: Hxy, Hxz, Hyx, Hyz, Hzx, Hzy, where the first and the second indexes indicate the orientation of transmitter and receiver, correspondingly) , at ten frequencies in the range...

... limitations associated with battery-powered logging tools. The tool's static magnetic field geometry was optimized to provide reliable measurements in the hostile LWD environment and to have negligible interference on well-survey instrumentation. The tool can be placed anywhere in the bottom-hole assembly...

... 3DEX TM by Shell and Baker Atlas is such an example (Beard et al., 1998, Kriegsh~iuser tal., 2000). The first generation of the tool measures 5 magnetic field components: Hxx, Hyy, Hzz, Hxy, and Hxz (Figure 1). Induction logging data are nonlinear functions of the resistivity structure, the relative...

... real time system log analysis undersaturated oil sand total porosity Upstream Oil & Gas spwla 42 porosity application interpretation magnetic field Acquisition Parameter Halliburton Energy Service objective Symposium well logging Prammer Engineer Development Team...

... Symposium well logging synthetic response induction data magnetic field Rabinovich resistivity Upstream Oil & Gas apparent conductivity vertical resistivity conductivity correction log analysis isotropic model anisotropy spwla 42 coefficient vertical resolution horizontal resistivity...

... for dipping angles within a range of 90 + 15 degrees. modeling induction tool cheryauka resistivity well logging borehole geophysics compensation wellbore invasion log analysis approximation magnetic field Symposium coordinate system Upstream Oil & Gas invasion resistivity...

...) and for a typical grain size (0.1–1.0 mm), all appreciable effects are linear with respect to the frequencies used in HDIL (10–150 kHz). The effects of pyrite can be divided into inductive and galvanic contributions. Inductive effect is due to eddy currents excited in the pyrite grains by the direct magnetic field...

.... Evaluation of the effect of internal field gradients on nuclear magnetic resonance (NMR) spin-spin (Ts) relaxation is essential to formation evaluation. In this paper, systematic methods are developed to calculate magnetic fields and gradient distributions for three types of porous media. Magnetic fields...