LOS RESERVORIOS DE LA SERIE TOBÍFERA EN LA ESTRUCTURA DICKY/ JAUKE, BLOQUE FELL, CUENCA AUSTRAL/MAGALLANES, CHILE
Destéfani, Ernesto Zolezzi Mir, Dalmiro Musso, Juan E.
LOS RESERVORIOS DE LA SERIE TOBÍFERA EN LA ESTRUCTURA DICKY/ JAUKE, BLOQUE FELL, CUENCA AUSTRAL/MAGALLANES, CHILE - 20 p. ; 1-19
The Serie Tobífera is composed by volcanic and volcaniclastic rocks and is made up of several filing events controlled by the development of half-grabens at the syn-rift stage of the basin during Mid to Late Jurassic. The reservoirs, associated mostly with ignimbrites and rhyolitic lavas, are frequently found in the first 50 m at the top of the sequence and can be classified based on the origin of their porosity in "primary", related with the emplacement and cooling of these rocks, and "secondary", which are generally associated with processes of dissolution and/or fracturing. In the case of the Dicky/Jauke structure, two exploratory wells have been drilled recently obtaining gas flow rates over 160.000 m3/day. In addition, another productive level located 150 m below the Serie Tobífera top has been documented, setting an interesting precedent for the history of the basin. As a result of this work, we can draw the following conclusions for the reservoirs in Dicky/ Jauke structure: 1) they correspond to vitric tuffs characterized as weakly welded ignimbrites, 2) main described porosity is intraparticular (primary), with variable participation of dissolution and microfractures, 3) they show an intense degree of silicification, 4) their seismic response corresponds to relative high acoustic impedance anomalies, and 5) the high productivity evidenced at the wells do not correspond with the poor petrophysical conditions observed in sidewall cores and electric logs, probably due to the presence of naturally fractured reservoirs = Simposio de Magmatismo y Sistemas Petroleros "Dr. Eduardo Llambías"
068.82 553.28 C62 15730
LOS RESERVORIOS DE LA SERIE TOBÍFERA EN LA ESTRUCTURA DICKY/ JAUKE, BLOQUE FELL, CUENCA AUSTRAL/MAGALLANES, CHILE - 20 p. ; 1-19
The Serie Tobífera is composed by volcanic and volcaniclastic rocks and is made up of several filing events controlled by the development of half-grabens at the syn-rift stage of the basin during Mid to Late Jurassic. The reservoirs, associated mostly with ignimbrites and rhyolitic lavas, are frequently found in the first 50 m at the top of the sequence and can be classified based on the origin of their porosity in "primary", related with the emplacement and cooling of these rocks, and "secondary", which are generally associated with processes of dissolution and/or fracturing. In the case of the Dicky/Jauke structure, two exploratory wells have been drilled recently obtaining gas flow rates over 160.000 m3/day. In addition, another productive level located 150 m below the Serie Tobífera top has been documented, setting an interesting precedent for the history of the basin. As a result of this work, we can draw the following conclusions for the reservoirs in Dicky/ Jauke structure: 1) they correspond to vitric tuffs characterized as weakly welded ignimbrites, 2) main described porosity is intraparticular (primary), with variable participation of dissolution and microfractures, 3) they show an intense degree of silicification, 4) their seismic response corresponds to relative high acoustic impedance anomalies, and 5) the high productivity evidenced at the wells do not correspond with the poor petrophysical conditions observed in sidewall cores and electric logs, probably due to the presence of naturally fractured reservoirs = Simposio de Magmatismo y Sistemas Petroleros "Dr. Eduardo Llambías"
068.82 553.28 C62 15730
