A Systematic Volcanic Intrusive Characterization Model for Exploration and Production of Vaca Muerta Formation
Authors
Silvana Utge (YPF S.A.) | Marta D’Angiola (Weatherford) | Fabián Dominguez (YPF S.A.) | Daniel García (YPF S.A.) | Ronyl Ruiz (Weatherford) | Jesús Rodríguez (Weatherford) | Gustavo Pérez (YPF S.A.)
Publisher
SPE - Society of Petroleum Engineers
Publication Date
July 27, 2020
Source
SPE Latin American and Caribbean Petroleum Engineering Conference, 27-31 July, Virtual
Paper ID
SPE-199109-MS
Abstract
This paper presents a new approach based on a systematic workflow that diminish the uncertainties regarding heterogeneities and other geological factors that dramatically impact the unconventional reservoir performance in Vaca Muerta. In addition to the natural heterogeneities caused by marine depositional sub-environments that formed rock configuration variability, both vertically and horizontally, some areas of Vaca Muerta are affected by subsequent volcanic activity that creates complex characteristics for drilling and completions.
A detailed geological, mineralogical and petrophysical characterization from the pilot well is performed to precisely determine landing points as well as the identification of traversed volcanic intrusive bodies. Pilot hole characterization added comprehensive knowledge to the horizontal drilling operations using Geosteering by decreasing geological uncertainty and allowing full control of drilling through the LWD azimuthal information in real time, and therefore making decisions to obtain optimal well placement. Critical information about elemental gamma ray spectroscopy (U / Th/ K, e.g.), that revealed specific reservoir characteristics of the depositional environment, supported the hypothesis of the heterogeneity of Vaca Muerta Formation and helped to identify the intrusive bodies.
The workflow is completed with a complete structural evaluation, identification of natural fractures and textures from electrical borehole images logged in Oil-based mud environment. This analysis defined precisely the intrusive (dikes and sills) configurations. Textural and mineralogical characteristics, as well as information about their location, spatial and relative geometric development are included in the evaluation. The analysis provided critical inputs for completion decisions as well. Operational and evaluation results are used as the platform for future developments of new exploratory non-conventional areas.