Authors :
Jhonny Edgar Casas; Elimar Gudiño
Volume/Issue :
Volume 6 - 2021, Issue 12 - December
Google Scholar :
http://bitly.ws/gu88
Scribd :
https://bit.ly/3z6EyQb
Abstract :
t:- The Orinoco Heavy Oil Belt (Venezuela) has
460 km long and between 40 and 80 km wide, with a total
area of 55,300 km2, containing the biggest extra-heavy oil
reserves in the world. Within this belt, the Miocene
Oficina Formation in the Petrocedeño field, Junín area,
has been producing extra-heavy oil (8.5° API) for more
than 20 years. The field development has generated a
detailed picture of its structural, sedimentological and
stratigraphic setting, along with an excellent
understanding of its static/dynamic properties. Reservoir
zonation was successfully applied based on a 3rd-order
sequence stratigraphic framework for which a detailed
sedimentological understanding was crucial. In the study
area, Lower Oficina Formation (Morichal Member) is
characterized by a fluvial dominated system at the base,
to a tide-dominated lower delta plain and subsequently a
tide-dominated, subtidal, upper deltaic-platform to the
top. The current sequence stratigraphic model cannot
explain the presence of anomalous thick channelized
sandstones with an apparent erratic distribution in the
upper part of the interpreted transgressive system tract.
The detailed study of the C1 parasequence set, allowed the
identification of a sequence boundary not recognized in
previous models. This sequence boundary was the result
of a relative sea level fall, creating an incised valley
system. These incised valleys show great complexity and
sinuosity, creating a very narrow and localized network
in the study area. 3D seismic, a dense network of wells
(vertical, inclined and horizontal) and a number of cores,
allowed the construction of high-resolution model to
enable the optimization of cold production in this area
Keywords :
Orinoco Heavy Oil Belt; Oficina Formation; Sequence Stratigraphy; Venezuela
t:- The Orinoco Heavy Oil Belt (Venezuela) has
460 km long and between 40 and 80 km wide, with a total
area of 55,300 km2, containing the biggest extra-heavy oil
reserves in the world. Within this belt, the Miocene
Oficina Formation in the Petrocedeño field, Junín area,
has been producing extra-heavy oil (8.5° API) for more
than 20 years. The field development has generated a
detailed picture of its structural, sedimentological and
stratigraphic setting, along with an excellent
understanding of its static/dynamic properties. Reservoir
zonation was successfully applied based on a 3rd-order
sequence stratigraphic framework for which a detailed
sedimentological understanding was crucial. In the study
area, Lower Oficina Formation (Morichal Member) is
characterized by a fluvial dominated system at the base,
to a tide-dominated lower delta plain and subsequently a
tide-dominated, subtidal, upper deltaic-platform to the
top. The current sequence stratigraphic model cannot
explain the presence of anomalous thick channelized
sandstones with an apparent erratic distribution in the
upper part of the interpreted transgressive system tract.
The detailed study of the C1 parasequence set, allowed the
identification of a sequence boundary not recognized in
previous models. This sequence boundary was the result
of a relative sea level fall, creating an incised valley
system. These incised valleys show great complexity and
sinuosity, creating a very narrow and localized network
in the study area. 3D seismic, a dense network of wells
(vertical, inclined and horizontal) and a number of cores,
allowed the construction of high-resolution model to
enable the optimization of cold production in this area
Keywords :
Orinoco Heavy Oil Belt; Oficina Formation; Sequence Stratigraphy; Venezuela
