He was born in 1914 in San Miguel de Tucumán, Argentina. In 1925 he moved to Rosario, Santa Fe, where he died in 1992.
Since 1939 he participated in many solo and group exhibitions and in several art salons across Argentina. He carried out an intensive educational work in his home workshop, attended by many generations of artists.
He received numerous awards, such as the Rosario Prize and the Emilio Pettoruti Prize for Painting from the Argentine National Arts Fund.
He was a member of Mutualidad Popular de Estudiantes y Artistas Plásticos de Rosario. He was cofounder of Grupo Litoral. His referents were Antonio Berni, creator of Mutualidad, and Joaquín Torres García, who taught him the aesthetic and philosophical premises of Constructive Universalism, which guided his production during the 50s and 60s.
Among his awards are: First Prize, National Salon of Rosario (1941, 1942 and 1945); Acquisition Prize, Council for Culture, I Litoral Salon (1942); Acquisition Prize, Annual Salon of Artists from Rosario (1944); Acquisition Prize, Chamber of Deputies of the Province, XXIV Annual Santa Fe Salon (1948); Cecilia Grierson Prize, XXXVIII National Salon of Buenos Aires (1948); Acquisition Prize, Ministry of Justice, XLI National Salon of Buenos Aires (1951); Frans Van Riel Prize, XXXIX Salon of Watercolorists and Engravers (1957).
In August 2016, to inaugurate the new space, Diego Obligado Art Gallery presented a series of selected drawings by Grela.
Untitled, 1988 Oil on canvas 108 x 160 cm
Pkmy, 1987 Oil 45 x 45 cm
KANYYAY KJA XI, 1985 Oil on hardboard 75 x 55 cm
Untitled, 1976 Oil on canvas 100 x 80 cm
El rancho del gato, 1959 Pencil on paper 24.5 x 32 cm
El barco, 1957 Ink on paper 50 x 65 cm
El galpón, 1957 Ink on paper 50 x 65 cm
La esquina, 1957 Pencil and watercolor 30 x 43 cm