The Vaca Muerta Formation, located in the west-central part of Argentina, holds great potential as an unconventional shale gas and oil resource play. Like other unconventional resources, the most challenging aspect of developing Vaca Muerta was to optimize the drilling strategy to improve hydrocarbon production, through an efficient geological sequence description. an efficient geological sequence description. Thus, the aim of this study was to characterize the Vaca Muerta system and improve understanding of the reservoir’s characteristics.
The geoscientists at YPF adopted the Paradigm SeisEarth® interpretation system to perform detailed, multi-scale, structural and stratigraphic interpretation from a very large dataset. All automated and semi-automated processes for interpreting seismic data were easily applied, delivering high quality results within a short period of time.
This multi-disciplinary interpretation workflow resulted in the description of four second order sequences; each was described in terms of its own architecture, depositional pattern style, internal litho-stratigraphic configuration and seismic signature.
This result was enabled by simultaneously interpreting different types of seismic attributes using interpretation techniques enabled by SeisEarth. Based on this approach, acoustic impedance was a determining attribute in individualizing the different sequences: Sequence #1 was associated with predominantly low values, while there was a graduation from high to low in Sequences #2 and #3. Sequence #4 was mainly defined by high values of acoustic impedance.
After defining the stratigraphic sequence correlated with the seismic attributes, it was possible to create a model that matched the geological, well core and production data.
These sequences are now being used by the exploration team to improve the location of future appraisal wells and to prepare development plans. The next step will be to perform correlation of a vertical succession of lithofacies with seismic facies. This will allow the team to define sweet spots in a predictable volumetric distribution, helping them to improve their development strategy.
This study shed light on the high heterogeneity of the Vaca Muerta Formation, which was previously thought to be simple and homogeneous source rock. A better understanding of the rock variations enabled more efficient well stimulations. The visualization and interpretation functionalities in SeisEarth were essential tools for discerning the subtle changes in the rock properties.
“For over five years, I have used SeisEarth to perform a wide variety of interpretation tasks, including attribute calculation, opacity visualization, multi-3D seismic merge, well path design, flattening, horizon slices, multi-survey visualization, and color palette manipulation. Use of SeisEarth has led to important advances in the exploration of unconventional plays in Argentina.”
David Guerberoff, YPF Geophysicist