AAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
Impact of Accurate Velocities from Signal Fidelity Enhancement for Reliable Seismic Interpretation - Example from Kuwait
(1) Exploration, Kuwait Oil Company, Kuwait, Kuwait.
In September 2008 Kuwait Oil Company (K.S.C.) acquired a 3D seismic survey across Arifjan area, S-E Kuwait. The primary objective of this survey is to image the Mid-Marrat Jurassic reservoir through maximizing the signal fidelity and the vertical resolution.
Following the processing of the seismic data, it was clearly recognized that the velocity
analysis/picking, interpretation and
velocity
field modeling are the most crucial steps for enhancing the temporal resolution, needless, to say very challenging to achieve.
Accurate velocities have a great impact on flatting the gathers and consequently enhancing the frequency contents; the subtle changes in both RMS and interval velocities have shown a significant effect on some of the main processing stages such as residual statics calculation, de-multiple techniques, imaging and stacking
, a special care of handling the
velocity
analysis and picking was considered.
In addition to the effective data preconditioning prior to the velocity
analysis, different powerful
velocity
analysis tools were tested to identify the most suitable ones to use. Important processing steps were applied prior to
velocity
analysis to precondition the data for such as noise attenuation, multiple removal and inner trace mute.
Several rounds of interactive velocity
picking have been run to fine tune the
stacking
velocities in order to achieve the best
stacking
response. Continuity and resolution of seismic horizons apparent anisotropic and high order
moveout
were tested. Finally the Spatial Continuous
Velocity
Analysis (SCVA) has been applied to achieve a much higher accuracy in the picking of
stacking
velocities. These refined velocities were then passed through a
velocity
model builder (VMB) to stack the final product ready for interpretation.
This case study will present the different velocity
analysis techniques applied and will focus on the results achieved using these techniques and its impact on improving the seismic interpretation.