SPWLA
Monthly Luncheon Meeting
Thursday – September 20, 2018
PanAm Building- Suite 1600
601 Poydras St, New Orleans, LA 70130
11:30 – 1:00 pm
or email Elizabeth Tanis ([email protected]) with RSVP
Towards 3D Reservoir Mapping Using Deep Directional Resistivity
Presented By: Dzevat Omeragic
Scientific
Advisor, Schlumberger
ABSTRACT
Since its introduction more than a
decade ago, the deep directional resistivity technology for proactive geosteering
had revolutionized well placement efficiency, maximizing the reservoir contact,
with direct impact on cost and recovery. We will overview the status of the
measurement and related interpretation technology, including recent progress
towards the 3D reservoir mapping.
Currently the real-time interpretation
of deep directional resistivity measurements is based on continuous inversion
for a locally 1D layered resistivity profile, generating an approximate 2D
resistivity map along the well path. The novel model-driven inversion
methodology provides a high-definition reservoir map suited for narrow strata
delineation and early reservoir detection to be used in well placement
operation. By integrating the prior field geology knowledge and information from
offset wells as reference patterns, the algorithm is able to consistently and
accurately map finer features of the layered formations further away from the
wellbore, resulting in an enhanced and expedited real-time steering
decision-making process. A field example illustrate how interpretation helped
to better understand the well production behavior
All practical inversion approaches so
far were ignoring the information on lateral changes of the reservoir, only
providing a longitudinal 2D snapshot of the 3D reservoir structure around the
well. The newly developed deep pixel-based 2D azimuthal imaging inversion is
able to map lateral reservoir heterogeneities. It takes advantage of full 3D
sensitivities of deep directional resistivity measurements. When applied in
real-time while drilling, it has potential to significantly reduce drilling
hazards as it will enable true 3D steering towards or away from lateral
targets. Imaging was applied to consistent imaging of faults on a side of the
wellbore, when approaching, crossing and moving away from the fault.
We also present an innovative
integration methodology to build a realistic, high resolution geomodel
reconciling all the subsurface measurements made at different scales, including
real time LWD measurements, 1D and 2D resistivity inversions, interpreted dips
and time lapse seismic data. The measurement integration significantly improves
the understanding of the 3D reservoir structure and fluids distribution,
benefiting the planning and drilling of horizontal wells, especially to
optimize geosteering for productivity of infill wells in the complex settings
of mature fields.