The FMI fullbore formation microimager gives you microresistivity formation images and dip data in water-base mud, differentiating the structures and. UltraTRAC all-terrain wireline tractor conveys FMI microimager ft in carbonate reservoir lateral in only 7 h, New Mexico. The FMI-HD high-definition formation micro-imager employs the well-proven microresistivity imaging approach of the industry-standard FMI fullbore formation .
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Brochure: FMI Fullbore Formation MicroImager
Moreover, the schlumbegger signal is degraded in elliptical and oval wellbores because of non-normal incidence. The borehole televiewer operates with pulsed acoustic energy so that it can image the borehole wall in the presence of opaque drilling muds.
This requirement has limited the application of downhole cameras. The first has been to develop a new synthetic mud that retains all the stabilizing characteristics of conventional synthetic muds but is sufficiently conductive to permit microresistivity imaging measurements.
The tool can also be used for investigating the geometry of the inner surface of casing where it is not desired to measure resonant ringing as an indicator of cement integrity.
FMI-HD High-Definition Formation Microimager | Schlumberger
The FMI tool is able to detect laminations as thin as 0. The resolution of electrical microimaging tools is governed by the size of the buttons, usually a fraction of an inch. This problem is more serious in heavily weighted muds, which are the most opaque acoustically, and it gives rise to a loss of image resolution. Borehole imaging has been one of the most rapidly advancing technologies in wireline well logging.
Short bursts of acoustic energy are emitted by a rotating transducer in pulse-echo mode.
The first borehole televiewer, operating at a relatively high ultrasonic frequency of 1. The third factor is the scattering or absorption of acoustic energy by particles in the drilling mud. Specific applications are fracture identification, analysis of small-scale sedimentological features, evaluation of net pay in thinly bedded formations, and the identification of breakouts irregularities in the borehole wall that are aligned with the minimum horizontal stress and appear where stresses around the wellbore exceed the compressive strength of the rock.
Optical imaging Acoustic imaging Electrical imaging Methods that draw on both acoustic and electrical imaging techniques using the same logging tool Prensky  has provided an excellent review of this important subject.
Electrical microimaging tools have proved superior to the ultrasonic televiewers in the identification of sedimentary characteristics schlujberger some structural features such as natural fractures in sedimentary rocks. Microresistivity imaging devices were developed as an advancement on dipmeter technology, which they have mostly superseded.
Acoustic impedance provides an acoustic measure of the relative firmness of the formations penetrated by the wellbore material and, thus, it has the capability of discriminating between different lithologies, with high acoustic impedance giving rise to high reflected amplitudes. Today they furnish a true high-resolution color image of the wellbore.
The applications range from detailed reservoir description through reservoir performance to enhanced hydrocarbon recovery. The other major historic limitation, the need to fni until the camera is recovered before the images can be seen, has fallen away with the introduction of digital systems.
Thus, the borehole televiewer also operates as an acoustic caliper log. However, in this downhole case, the aperture of the sensor gives an intrinsic spatial resolution of 0.
Borehole imaging –
The high-resolution image is normalized with respect to the low-resolution part of the signal or to another resistivity sschlumberger tool. The conventional microresistivity imaging devices require a conductive mud in which to function. The arrangement is reminiscent of the Schlumberger schlumberver array that is still used for surface resistivity sounding in geoelectrical prospecting.
Each pad contains two current electrodes and a set of five pairs of closely spaced potential electrodes positioned centrally between the current electrodes Fig.
There are two positional modes:. An applied voltage causes an alternating current to flow from each electrode into the formation and then to be received at a return electrode on the upper part of the tool. The first is the shape of the borehole wall itself: Use this section for citation of items referenced in the text to show your sources. Ultrasonic measurements can be made using the same tool in all types of drilling mud, and this can facilitate interwell comparisons.
These differences can be accommodated through the combined use of electrical and acoustic imaging. Although the caliper can reveal the orientation of breakouts, the tool provides little information about their size and, more generally, about the overall shape of the borehole wall.
These travel through the drilling mud and undergo partial reflection at the borehole wall. The tool does not provide an absolute measurement of formation resistivity but rather a record of changes in resistivity.
FMI-HD High-Definition Formation Microimager
Data are usually presented as depth plots of enhanced images of amplitude and borehole radius. This problem was dmi by the so-called oil-based mud dipmeters. The buttons have a diameter of 0. Traditionally, they have required a conductive borehole fluid, but it will be seen later that this requirement has been obviated by oil-based-mud imaging tools.
The combination of FMI images and dip data clearly differentiates the eolian and interdune sands in this 8. The pads and flaps contain an array of button electrodes at constant potential Fig.