Print this pageLeading the Way to Detailed Geologic Description While Drilling
Pavlovic, Mitch D., Baker Atlas,
The use of borehole image data is an increasingly critical
component in evaluating the full potential of a field prior to initiation of
the development phase. Over the years, a number of technological advances have
significantly improved quality of the wireline
electrical and acoustic borehole imaging technology. Recent advances in logging
while drilling (LWD) technology allow for high-resolution formation imaging to
be successful in wells drilled with both conductive and non-conductive
(oil-based) muds. Advancements in LWD measurement
quality broaden uses from initial while-drilling steering applications
(reservoir navigation), into structural interpretation, 3-D fracture system
characterization, stratigraphic analysis,
conventional core description and petrophysics
integration, leading the way to detailed geologic description while-drilling.
High-resolution visualization of near wellbore
geology while-drilling has many advantages including the better shaped
borehole at the time of drilling, significantly reduced invasion profile
effects and 100% circumferential borehole coverage (unlike the pad coverage of
micro-resistivity wireline
imagers). Above all, real-time imaging capabilities (i.e. images sent to the
surface in real-time), optimized in definition given telemetry restrictions,
allow for early indication of formation characteristics and may be effectively
used for making important operational decisions.
This paper will
review currently available LWD borehole imaging technologies and resulting
geologic applications, including azimuthal density, azimuthal gamma ray and recently introduced micro-resistivity device. Comparison with wireline
imaging technologies and conventional core data will be also presented. Field
data presented here include data acquired in a range of geological environments
and borehole conditions, including horizontal wells.