Condensate Gas Blockage Simulation in A Gas Reservoir: A Case Study of A Gas Field in the Mahakam Delta, East Kalimantan, Indonesia

Abstract

The effects of condensate gas blockage in the gas reservoir in the Mahakam Delta, East Kalimantan, Indonesia, are successfully simulated. Condensate blockage arises during gas production due to decreasing reservoir pressure. Gas production causes the isothermal pressure of the reservoir to fall, producing condensate accumulation in front of the wellbore and causing a decrease in the permeability and productivity of the well. The key parameters that control condensate gas blockage are pressure, permeability, and the relationship between pressure, volume, and temperature (PVT). This paper presents a simulation of condensate gas blockage in the Mahakam Delta gas field, East Kalimantan, Indonesia. Condensate gas blockage was simulated for two production wells that are controlled by the physical properties of the rock, such as its acoustic, elastic impedance, and permeability. The simulation results showed that the reservoir pressure decreases gradually, starting with decreasing pressure in the well. Condensate gas was formed when the pressure reached 3100 psig and was observed throughout the reservoir depending on the pressure and permeability distribution; condensate gas blockage readily occurs in a reservoir with low permeability. This paper proposes two drilling program scenarios that involve well stimulation and horizontal well drilling to overcome the condensate gas blockage. Well stimulation was applied in order to increase the permeability around the wellbore using fracturing, while horizontal well drilling aimed to increase the permeability and to enhance the coverage of the reservoir layer. Simulation of these two scenarios showed that horizontal well drilling provides a higher gas recovery factor than well stimulation.