Optimize drilling and completion strategy with cost-efficient solution

The Vaca Muerta Formation in Neuquén, Argentina, contains complex Mesozoic shales and is rich in tight oil and gas but requires multiple data sets to understand production potential. Tecpetrol needed to evaluate production potential in a vertical well in the formation to optimize drilling and completion design; however, well conditions precluded running wireline. Tecpetrol sought a cost-efficient solution that would provide an accurate evaluation of rock heterogeneity to assess production potential, support hydraulic fracturing operations, and help place the lateral.

Evaluate rock heterogeneity from cuttings

Schlumberger recommended using the LithoFlex service to provide a cost-efficient near-real-time formation evaluation using the HRDM, XRF, and DRIFTS components. Together, these components provide accurate and comprehensive measurements of lithology, mineralogy, and elemental composition from cuttings, enabling a well-informed comparison of rock heterogeneity. By accurately capturing the geochemical fingerprint in the vertical well, fracturing operations can be optimized, and the best productive intervals can be used to guide lateral placement.

Accurately characterized formation to identify productive zones

The LithoFlex evaluation-while-drilling service quantified both organic and inorganic matter and identified shale lithofacies to help optimize the number and location of fracturing stages in the vertical section. The well was fractured in four stages, and the production results from each stage correlated with the formation evaluation provided by the LithoFlex service. For example, the first stage provided initially good production flow with a fast decline.The LithoFlex service identified a high concentration of clays, particularly smectite, and trace elements such as nickel and molybdenum, which correspond with a highly reductive environment. Highly reductive environments induce a better preservation of organic matter however lead to potential instability in geomechanical and production efficiency.

The LithoFlex service identified the best productive intervals by obtaining measurements of preserved organic matter and total organic carbon (TOC). These key measurements correlated with good production rates in the second and fourth fracturing stages and enabled Tecpetrol to determine the optimal depth to place the lateral.