Fault seal analysis for VS area, block 16 -1/15, Cuu Long Basin, Viet Nam

Abstract

Fault-bound traps represent an important class of hydrocarbon-bearing
structure. Whether a fault can seal hydrocarbons on a geological
timescale may be controlled by one or more of three conditions: (1)
sealing due to lithological juxtaposition, where reservoir rock is
juxtaposed against sealing rock across the fault; (2) sealing by the fault
damage zone, which forms a barrier composed of low-permeability clay
within the fault zone and (3) the tectonic activity of the fault, as during
faulting, hydrocarbon accumulations can be destroyed and leakage
along the fault zone. This research employs an indirect method to
establish a correlation between pressure and the sealing properties on
fault surfaces, such as the SGR (Shale Gouge Ratio), across various
formations under the same geological conditions from all fields within
the region and around the world. This aids in assessing the sealing
potential of the faults. Evaluate the fault seal capacity according to 3D
model for the structures in Oligocene D, Oligocene C and Lower Miocene
sediments to serve the assessment hydrocarbon potential in VS area and
reduce the risk for further exploration - appraisal work in block 16-1/15,
Cuu Long basin. Geology, seismic and petrophysical data were used to
construct 3D structural frameworks, lithology model and Vclay model.
Parameters such as fault throw, Vshale, lithology, bed thickness, burial
depth history, fluid density and pressures, ect. are incorporated into fault
seal analysis and also estimate the maximum hydrocarbon column
height can be held by each fault in study area, therefore helping to assess
the hydrocarbon potential in undrilled structures in VS area