Reducing prospect uncertainty in a frontier exploration play using forward AVO modeling: A case study offshore Mauritania

Konings, Stijn Pieter Marie (Kosmos Energy LLC) | Hyde, Emma (Kosmos Energy LLC) | Noah, Jesse (Kosmos Energy LLC) | Schneider, Rhys (Kosmos Energy LLC) | Groves, Lee (Kosmos Energy LLC) | Deina, Chemsdine Sow (SMHPM)


In April 2015 Kosmos Energy discovered the Ahmeyim (formerly Tortue) gas field, followed by the discovery of the Bir Allah (formerly Marsouin) gas field, opening a new hydrocarbon province offshore Mauritania outboard of the proven upper slope salt play. Ahmeyim and Bir Allah encountered Cenomanian and Albian sands in a middle to lower slope setting. The hydrocarbon bearing sands exhibit strong anomalous class 2 AVO (Amplitude Versus Offset) response relative to the background while the water sands do not. Interrogation of the well data reveals well constrained rock physics models for both reservoir sands, as well as the background shales. Narrow uncertainty ranges in the relationships between the elastic parameters constituting the rock physics models allow for the construction of accurate forward synthetic AVO models. Comparison of these models to seismic AVO and migration velocity observations has successfully helped to reduce the pre-drill risk on reservoir presence, reservoir quality and reservoir fluid content. Confirmation of the models by consecutive wells has increased confidence in this exploration tool, but one should always remain cautious for unforeseen scenarios.

Presentation Date: Tuesday, September 26, 2017

Start Time: 2:40 PM

Location: 370D

Presentation Type: ORAL