SPEAKER: Nicholas Bennett - Schlumberger-Doll Research Center
Speaker Bio:
Nicholas
Bennett is currently a Principal Research Scientist at Schlumberger-Doll
Research Center,
Cambridge, Massachusetts where he has been working since completing his Ph.D.
in Mathematics
from Yale University in 1997 with Professor Ronald Coifman. Nick’s main activities
have involved acoustics, particularly sonic imaging, LWD conveyance of nuclear magnetic
resonance measurements, and imaging using LWD electromagnetic measurements.
.
Abstract: Paper JJJJ
A new sonic imaging technique uses azimuthal receivers
to determine individual reflector locations and attributes such as the dip and
azimuth of formation layer boundaries, fractures, and faults. From the filtered
waveform measurements, an automatic time pick and event localization procedure
is used to collect possible reflected arrival events. An automatic ray tracing
and 3D slowness time coherence (STC) procedure is used to determine the ray
path type of the arrival event and the reflector azimuth. The angle of
incidence of the reflected arrival is related to the relative dip, and the
moveout in 3D across the individual sensors is related to the azimuthal
orientation of the reflector. This information is then used to produce a 3D
structural map of the reflector which can be readily used for further
geomodeling.
This new technique addresses several shortcomings in
the current state-of-the-art sonic imaging services within the industry.
Similar to seismic processing, the current sonic imaging workflow consists of
iteratively testing migration parameters to obtain a 2D image representing a
plane in line with the desired receiver array. The image is then interpreted
for features, which is often subjective in nature and does not directly provide
quantitative results for the discrete reflections. The technique presented
here, besides providing appropriate parameter values for the migration
workflow, further complements the migration image by providing dip and azimuth
for each event that can be used in further downstream boundary or discontinuity
characterization.
A field example is presented from the Middle East in
which a carbonate reservoir was examined using this technique and subsequently
integrated with wellbore images to provide insight to the structural geological
setting, which was lacking seismic data due to surface constraints. Structural
dips were picked in the lower zone of the main hole and used to update the
orientation of stratigraphic well tops along the well trajectory. 3D surfaces
were then created and projected from the main hole to the sidetrack to check
for structural conformity. One of the projected surfaces from the main hole
matched the expected depth of the well top in the sidetrack but two were offset
due to the possible presence of a fault. This was confirmed by parallel
evaluation of the azimuthal sonic imaging data acquired in the main hole that
showed an abrupt change in the relative dip of reflectors above and below the
possible fault plane using the 3D STC and ray tracing. Dip patterns from both
wells showed a drag effect around the offset well tops, further confirming the
presence of a fault. A comparison of the acquired borehole images pinpointed
the depth and orientation of the fault cutting both wells to explain the depth
offset of the projected 3D well top surfaces.
Please Register THRU LINK IN EMAIL FROM [email protected] for only ONE session which fits your schedule.
There are two identical sessions:
Morning - Tuesday, May 7th, 8am – 9am US Central Time;
Evening - Wednesday, May 8th, 8pm – 9pm US Central Time.
**IMPORTANT Required Action to COMPLETE Webinar Registration:**
1. Complete checkout with SPWLA registration page (Fees: FREE to current members and Non-Members are $25.00)
2. RESPOND to second email from [email protected] with the LINK to complete the webinar registration. This step is required to view the webinar.