Diagenesis of the sandstones of a tight-gas reservoir: The Lajas Formation in the Huincul High, Neuquén Basin

• Autores: Rainoldi, Ana L.; Beaufort, Daniel; Franchini, Marta B.; Minisini, Daniel; Patrier, Patricia; Giusiano, Adolfo; Pons, María Josefina; Cesaretti, Nora N.
• Año de publicación: 2022
• Idioma: inglés
• Tipo de recurso: documento de conferencia
• Materia: Ciencias Exactas y Naturales; Tight-gas Reservoir; Lajas Formation; Neuquén Basin; Huincul High; Ciencias Exactas y Naturales
• Institución: Universidad Nacional de Río Negro

Fil: Rainoldi, Ana. Centro Patagónico de Estudios Metalogenéticos-CONICET. Depto de Geología, Universidad Nacional del Sur (UNS). Argentina.
Fil: Beaufort, Daniel. Université de Poitiers, IC2MP, CNRS-UMR 7285. Francia.
Fil: Franchini, Marta. Patagónico de Estudios Metalogenéticos-CONICET. Depto de Geología y Petróleo, Facultad de Ingeniería, Universidad Nacional del Comahue. Argentina.
Fil: Minisini, Daniel. Shell Technology Center. Estados Unidos.
Fil: Patrier, Patricia. Université de Poitiers, IC2MP, CNRS-UMR 7285. Francia.
Fil: Giusiano, Adolfo. Private consultant. Neuquén, Argentina.
Fil: Pons, Josefina. Universidad Nacional de Río Negro. Instituto de Paleobiología y Geología. Argentina.
Fil: Cesaretti, Nora. Depto de Geología, Universidad Nacional del Sur (UNS). Centro de Geología Aplicada y Medio Ambiente (CGAMA, CIC-UNS). Argentina.
The sandstones of the Lajas Formation represent the main tight-gas reservoir of the Neuquén Basin. Diagenesis plays a fundamental role in this type of reservoir because diagenetic minerals have a high impact on porosity and permeability. This study presents the diagenetic characterization of the Lajas sandstones located in the productive area of Sierra Barrosa, central part of the Huincul High in the Neuquén Basin. The objective is to evaluate diagenetic processes and their impact on reservoir quality. The facies analyzed belong to deltaic and uvial depositional systems with a variety of sub-settings including delta front (proximal and distal mouth bar), prodelta, delta plain (distributary channels and interdistributary bays), uvial channel inll and uvial plain deposits. The analyzed samples consist of very coarse-grained to ne-grained, medium- to poorly-sorted and texturally immature feldspathic litharenites and lithic feldarenites (sensu Folk et al. 1970) along with siltstones and subordinate ne-grained clast- and matrix-supported polimictic conglomerates. Detrital minerals include lithic fragments, mono- and polycrystalline quartz, and feldspar with K-feldspar>plagioclase. Lithic fragments are volcanic and volcanoclastic detritus and subordinate plutonic, sedimentary and metamorphic grains. The amount of cement varies considerably and includes pyrite, clays, quartz, feldspar, carbonates, barite and subordinated Zn-Pb suldes. Porosity depends on facies and their amount of cements.