+441518081136A discussion on seismic reservoir characterization of tight reservoir: Scope to further research combining fiber optics
2nd International Conference and Expo on Oil & Gas
December 02-03, 2019 | Dubai, UAE
Arijit Chattopadhyay, Misfera Al-Qahtani and Rachid Sablit
Kuwait Oil Company, Kuwait
Scientific Tracks Abstracts : J Ind Environ Chem
DOI: 10.35841/2591-7331-C3-014
Abstract:
In North Kuwait, Najmah Formation hosts fractured tight
carbonates and organic-rich kerogen layer, with average
thickness of about 50 feet at average depth of 14000 feet
below surface, characterized by low porosity and ultra-low
permeability. This unit is overlain by alternating Gotnia salts
and anhydrite layers. Destructive interference of coherent
noise in 3D seismic affects the consistency of seismic reservoir
characterization within Najmah interval, requires attenuation
to exploit seismic data. Application of model-based interbed
multiple attenuation reduces coherent noise interference,
improves imaging and characterization of the Najmah
formation.
Integration of rock physics modeling, full-azimuth P-wave
seismic analysis and pre-stack simultaneous seismic inversion
reveals that pore geometry can affect seismic anisotropy. In
fractured tight carbonates, low Vp/Vs ratio correlates with
relatively porous intervals, low pore aspect ratio and high
brittleness index / higher fracture density. Higher organic
richness of Najmah kerogen correlates with lower acoustic
impedance. Azimuthal seismic analysis highlights existence
of multi-azimuth fracture sets within Najmah interval and
fast interval velocity coincides with direction of maximum
horizontal stress. Combination of brittleness index and fast
velocity azimuth can help identifying “sweet spots”within
Najmah formation.
Distributed Acoustic Sensing (DAS) fiber optics cable can
acquire 1D and 3D borehole seismic. S/N ratio of raw DAS
data is lower than geophone data and DAS is sensitive
only to the axial deformation of fiber optic cable. This
has downgraded DAS to a 1C geophone. DAS data can be
acquired continuously throughout length and life of well,
in contrast to geophones. Smart downhole deployment of
helically wound DAS can enhance permanent monitoring and
reservoir characterization by cross-well tomographic imaging
and recording of microseismic events in tight reservoirs like
Najmah Formation. Pragmatic use of fiber optics has potential
to illuminate fracture systems, identifying the coherent noises
of subsurface in evaluation unconventional reservoirs around
the world.
Biography:
Arijit Chattopadhyay has completed his M.Sc. at the age of 25 years from Indian Institute of Technology, Bombay, India. He is working in R&D Programmes Team of KOC, Kuwait. He has several publications and US Patent in recent years. He is a fellow of Geological Society of London and has over 14 years of global experience in E&P industry collaborative research in reputed academic institutions in India and USA.
E-mail: achattopadhyay@kockw.com
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