Description [caption id="attachment_849" align="alignright" width="256"] Figure 1. Schematic of the GLT tool[/caption] Geochemical Logging Tool (GLT) used three separate modes of gamma-ray spectroscopy to obtain measurements of most of the major oxides that make up sedimentary and igneous rocks. Initial measurements provided estimates of Si, Al, Fe, Ca, K, U and...
Description The Dipole Sonic Imager Tool (DSI-2) combines high-speed telemetry with simultaneous, 12-bit dynamic range digitization of an eight-receiver array. The sonde incorporates both monopole and crossed-dipole transmitters with an eight-station array of electronically configurable hydrophones for monopole and dipole reception. Combining new dipole-based technology with...
Description The Dual Laterolog (DLL) provided two resistivity measurements with different depths of investigation into the formation: deep (LLd) and shallow (LLs). In both devices, a current beam 2 ft-thick (A0) was forced horizontally into the formation by using focusing (also called bucking) currents (A1- A2,...
Description The Enhanced Digital Telemetry Cartridge (EDTC-B*) is a downhole tool that combines two commonly run sensors with a high-speed telemetry downhole modem that can be used in high-pressure and high-temperature environments. The primary function is to provide high-speed (over 1 Mbps) communications between the wireline...
Description The GPIT* General-Purpose Inclinometry Tool provides inclinometer measurements. Tool orientation is defined by three parameters: tool deviation, tool azimuth, and relative bearing. The GPIT tool uses both a three-axis inclinometer and a three-axis magnetometer to make measurements for determining these parameters. The basic principle of downhole...
Description The LWD-CDR was an electromagnetic propagation and spectral gamma ray tool built into a drill collar. It had many similarities to dual induction tools: it responded to conductivity rather than to resistivity, operated in water- or oil-base muds, and provided two depths of investigation. It had better vertical resolution,...
Description [caption id="attachment_473" align="alignright" width="180"] Sixteen-electrode arrangement for the four-pad tool.[/caption] The Formation MicroScanner sonde (FMS) consists of four orthogonal imaging pads each containing 16 microelectrodes which are in direct contact with the borehole wall during the recording. The button current intensity is sampled every 0.1 in...
Description The Azimuthal Resistivity Imager (ARI) was a laterolog tool that made deep measurements and azimuthal resistivity images around the borehole. At the time it helped analyze features and details that escaped conventional resistivity measurements: thin beds (down to 8 in, 20 cm), borehole formation heterogeneity,...
Explanation of Acoustic Wave Propagation Monopole compressional and shear Compressional and shear waves (sometimes referred to as p- and s-waves) are excited in the formation, along with various modes in the borehole, by a monopole source operating at high frequencies (typically 10-20 kHz). They propagate as body...
Depth correlations and core-log integration Total gamma-ray log curves, which are acquired with every toolstring combination, are normally used to depth match all of the logsobtained in any one hole. The HSGR log from the Triple Combo is used as the base curve, and the SGR...