ABSTRACT: Advanced technology imaging of the Mudi Field, East Java improvements
utilizing pre-stack depth migration
Shields, Martin L., M. Fauzi , Pertamina/Santa Fe JOB Tuban, Jakarta, Indonesia
Pre-Stack Depth Migration
(PSDM) has significantly improved the seismic image of the
Mudi Field (a Lower Miocene carbonate bank reservoir) in a structurally complex area.
Original low quality seismic images of the Mudi Field created low confidence in the top
reservoir interpretation and mapping that were essential to accurate reserve calculations.
This reduced image quality was primarily due to complex faulting that affected seismic ray
paths yielding shadow zones on the north flank of the field.
The objective of the PSDM reprocessing was to produce as accurate as possible a depth
image of the Mudi field with the current 2-D seismic and then convert to time thus
avoiding the artifacts induced by time migration
processing. This goal was accomplished by
selecting and implementing a process that iterated a detailed geological depth
interpretation with dense
velocity
analysis, creating a new structural/
velocity
model for
the field. The model was then applied utilizing the non-hyperbolic move out correction
from PSDM processing in depth producing a significantly sharper seismic image of the
field.
Results show that the depth image is well focused, with the northern flank more visible
and the fault plane well defined. The new structural/velocity
models produced improved
migrated seismic time data and represent a more accurate geological picture of the Field
when tied to the existing wells. Tangible benefits of the PSDM processing are optimum
placement of future development wells and increased confidence in the interpretation,
mapping and reserve estimates for the Mudi Field.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia