Geophysical reservoir monitoring feasibility study in a Central Saudi Arabian oil field

The Central Arabian field of this study is part of a trend of oil fields primarily producing from Permian sandstone reservoirs. The most productive zone, in the upper part of the reservoir, is characterized with good porosity and permeability, an aeolian depositional environment, and producing zones that tend to be laterally and vertically heterogeneous. The reservoir sandstone lenses are interspersed with low porosity/permeability siltstones. We examined the feasibility of watersaturation surveillance by geophysical means that could help to better produce the field and unravel certain production challenges; hence, time-lapse seismic (4-D) was considered. Using modeling, we argue that time-lapse seismic is a low probability candidate for successful reservoir monitoring of water saturation in this field. We also discuss other techniques that are potential alternatives, such as micro-seismicity, magnetotellurics and borehole gravity, comparing the relative merits and limitations of these methods as applicable to this field. Finally, we conclude with the potential impact of improved reservoir characterization, via integration of more seismic information into the reservoir model.