A New Frontier Unconventional Play in Northwest Peru: Lancones Basin

Abstract

Abstract

The preceding exploratory screening for unconventional plays in the forearc and sub-Andean basins of Peru has established a promising exploratory frontier, which nowadays has remained under-explored.

The favorable geological and geochemical characteristics of the Cretaceous source rocks of Talara and Sechura forearc basins in the Northwest Peru motivates the exploration of the adjacent Lancones Basin where the Albian Muerto Formation represents a potential world-class source rock. This work provides an initial insight into the geological features and unconventional play screening based on previous studies and available data.

Dark gray and black limestones, shales and marls compose the Muerto Formation of Lancones Basin. Furthermore, strong fetid odor and the abundance of fractures are key characteristics. Muerto formation outcrops on the northwestern margin of the basin forming a narrow belt of 55 Km in length with thickness between 100 and 389 m. On the other hand, only one exploratory well (Abejas-1X) reached the Muerto formation at the top of an anticline that only preserved a thickness of 89 m; however, seismic interpretation confirms its thickening and continuity throughout the basin.

The geochemical screening for the Muerto Formation indicates a high average TOC of 4 wt.% (n = 116), kerogen type II/III, marine organic matter and Ro values within the oil window (0.6% < Ro < 1.1%). Furthermore, the thermal maturity reaches the oil window in present-day outcrops, which suggests that Muerto Formation would reach the gas window in the subsurface at depths between 1,600 and 2,000 m according to the seismic interpretation.

This initial exploratory screening, together with favorable terrain conditions and accessibility to existing facilities and water sources, characterizes the potential Muerto formation as an attractive unconventional target that needs further exploratory efforts.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016