The Key Challenges for Pliocene Reservoirs Exploration in West El Manzala and West El Qantara Concessions, East Nile Delta Onshore, Egypt

Abstract

Exploration drilling in the Nile Delta has dramatically risen over the past 3 years, jumping from 5-10 wells/year up to 20-25 wells/year. Much of this recent drilling has been targeting the highly successful Pliocene play trend and the 2008 industry success ratio approached a phenomenal 90%.Thick sequences of Pliocene deep marine sediments have been successfully drilled and led to several offshore gas discoveries. No great exploration interest had been directed towards these good reservoirs in the onshore areas of the Nile Delta. Nevertheless, Dana Gas has been one of the most active and successful operators for this exploration target in its West El Manzala and West El Qantara Concessions.The gas sands of the Pliocene reservoirs are characterized by low velocities and densities compared with the surrounding shales and, subsequently, the top and base of the reservoirs have a "bright" seismic amplitude response. Additionally, the gas charged Pliocene reservoirs are often associated to acoustic impedance anomalies presence. The key challenge in the Pliocene reservoirs exploration is to understand the depositional environment with respect to the amplitude and acoustic impedance geometry from 3D seismic data through the cross-correlation between seismic facies character and the depositional pattern and environment. The main features and variations recognized in the reservoirs drilled to date in West El Manzala andWest El Qantara Concessions show a slow activity in the main basin evolution stage that seems to be not affected by high turbidity current flow or significant slope channeling. The early stage broad and straight channel system valley was cut and filled by younger channelized systems. Minor incisions of channel cuts are considered to be a key feature in defining channel fill development and sand distribution. SPE 127815A comprehensive study has been made recently on the Pliocene sequences in West Manzala and West Qantara concessions to assess the potentiality of El Wastani and Kafr El Sheikh Formations which represent the main reservoirs for the Pliocene sequence. The study has been focused on sequence stratigraphy analysis of the entire sequence to understand the depositional setting of the area through time as a fundamental support to the prospect generation and ranking of the area.The presence of shallow dry gas reservoirs with good productivity combined to a relatively cheap drilling cost makes the Pliocene exploration very attractive and economically profitable even for small accumulations. SPE 127815 3