Print this pageApplication of Sequence Stratigraphy in an Integrated Reservoir Characterization of the Jurassic Springhill Formation, Daniel Field, Chile
GOMEZ, ERNEST, STEPHEN D. STURM, and GUILLERMO OTZEN
Sequence stratigraphic principles have been applied in the characterization of the Jurassic Springhill Formation in the Daniel Field of southern Chile. The Daniel Field was discovered by ENAP in 1960 and total production has exceeded 40 MMBO and 75 BCF. Initial field development took place onshore and moved offshore into the Straits of Magellan in the late-1970s.
Production at Daniel Field is from fluvial and marine Springhill sandstones that rang in thickness from 15 to 100 meters. A sequence stratigraphic framework was established from the integration of cores and well logs from 220 wells. The Springhill is a third-order sequence consisting of nine stratigraphic units. The basal contact between the fluvial Springhill and underlying volcanoclastic and lacustrine deposits of the Tobifera Formation is a Type 1 unconformity. The fluvial lower Springhill includes valley-fill sandstones (SC1-SC6) that are interbedded with generally discontinuous overbank and lagoonal shales (SC2S and SC3S). This interval is a composite transgressive system tract (TST) comprised of several fourth-order sequences. A widespread marine shale (SMFS) separates the basal fluvial deposits from upper marine sediments and represents the maximum flooding surface (MFS) of the sequence. A glauconitic shoreface sandstone (SM1) deposited immediately above the shale is the uppermost reservoir unit. This sandstone and the overlying thick shale section represent the highstand system tract (HST) for the Springhill third-order sequence. Although limited reserves exist within the Daniel Field, this sequence stratigraphic mode can be used in the exploration and exploitation of Springhill reservoirs in surrounding areas.