Improve production decisions with accurate LWD data
Petroamazonas was developing the Coca-K field of eastern Ecuador and
sought to expand production by exploiting secondary reserves. It identified a
heterogeneous formation comprising limestone, dolomite, sand, silt, and clay in
an existing well's 12 1/4-in section. The operator ran a triple-combo logging
suite to characterize and evaluate the formation. However, because the
formation included carbonates mixed with shales, the triple-combo data for
porosity was inaccurate. Adding to the logging challenge was the condition of
the borehole, which was deteriorating along the 12 1/4-in section. The operator
sought a solution that would enable accurate characterization of the carbonate
sequences in the section, allowing all feasible pay zones to be exploited.
Evaluate formation producibility in real time using proVISION Plus
service
Schlumberger recommended running the proVISION Plus 825 service for the
first time in the country. The proVISION Plus service provides
lithology-independent porosity and continuous permeability for real-time
assessment of reservoir producibility. Using T2 distribution, irreducible and
producible fluid volumes can be derived for improved estimation of production
rates. These capabilities are particularly important for determining
permeability in heterogeneous carbonates and for identifying bypassed pay zones
in shaly sands.
To ensure full characterization of the carbonate section, Petroamazonas
ran the proVISION Plus service with a coring system so that the LWD data could
be compared with laboratory core measurements. Drilling fluid experts from M-I
SWACO, a Schlumberger company, helped optimize mud quality to ensure a smooth
run. Additionally, petrotechnical and geomechanics experts offered
Petroamazonas real-time drilling support. The team processed and QCed the data
in approximately 24 hours, allowing timely decisions to be made while
drilling.
Identified additional pay zone with core-quality measurements
Petroamazonas logged the interval in drilling mode with no interference
from the coring operation. Despite the size and deterioration of the well
section, the proVISION Plus service acquired logging data that accurately
reflected the rock properties as confirmed by core analysis. This precise data
provided insight that traditional triple-combo technologies could not in this
reservoir type.
The proVISION Plus service also identified an additional sand body that
was not expected for the geological sequence. The sand demonstrated good
quality, adding additional producible reserves for Petroamazonas in the
field.
