Pore Pressure Prediction in Unconventional Carbonate Reservoir

Abstract

Abstract Prediction of the formation pore pressure is considered as a significant simulation process during the drilling and production phases of the carbonate reservoir. The deficiency in this prediction allows for the occurrence of many troubles like blowouts, kicks, hole washouts, wellbore breakout, and stuck pipe. The most common conventional methods for the pore pressure prediction are Eaton's and Bower's methods which depend mainly on the normal compaction trend and commonly applied on Shales. The objective of this work is the prediction of the formation pore pressure by the application of the modified Atashbari prediction model upon the wireline logging data. This method depend on the porosity and the compressibility attribute of the rocks for the estimation of the pore pressure without any need for the normal compaction trends. The method was applied on the carbonate reservoir of the Middle Eocene Apollonia Formation, Abu El-Gharadig basin, Egypt. It is a gas bearing reservoir which characterized by its high porosity and low permeability. The results were compared with the other commonly used methods and show an improvement in the pore pressure estimation. It can be used as an individual method or in complement with other available methods.