Published: October 30, 2013 08:43
Using a multi-strand approach to shale pressure prediction, shallow offshore Niger Delta
Understanding Aikulola*, Jerome Asedegbega**, Steve O’Connor**, Richard Swarbrick**, Bitrus Pindar**, Lucas Oladipo**, Olusola Scott-Ogunkoya**, Folake Adesanya**, Adebayo Adedayo***, Kingsley Nwankwoagu***, Alexander Edwards**, Jakob Heller**, Patricia Kelly**, Ed Hoskin**, Austin Anaevune* and Samuel Olotu
Pressure prediction is challenging in the Niger Delta, as evidenced by the number of kicks taken, which is a sign of under-balanced drilling. Incorrect pore pressure prediction can lead to wrong choice of well design and hazards during drilling operations. From a current study of 42 wells from the Shallow Offshore Shelf of the Niger Delta we present the techniques used to interpret pressures in the Koronama-3 well.
The techniques presented included using velocity vs. density plots to determine overpressure mechanisms, using high quality seismic velocity data to interpret shale pressures and a model based on rates of sedimentation to establish theoretical limits with which to constrain the seismic-based interpretation.
What emerges is a multi-strand approach to pressure prediction, using independent data types to provide a more realistic pressure model.
*Shell Petroleum Development Company **Ikon Geopressure *** Sonar/Tusk, Lagos