Gas Recycling in Sarkhun Gas Condensate Reservoir Comparison of methane-nitrogen injection

The major specification of gas condensate reservoirs is the location of reservoir temperature between critical temperature and cricondentherm. In gas condensate reservoirs when the pressure falls below the dew point pressure condensate drops out in the reservoir. This heavy part of the gas has found many applications in industry and also in daily life, and by remaining in the reservoir not only this valuable liquid is lost, but also its accumulation will result in forming a condensate bank near the wellbore region which makes a considerable reduction in well productivity. This highlights the need to find an economical way to increase the condensate recovery from these reservoirs.To prevent this phenomenon to occur, the reservoir pressure should be maintained above the upper dew point pressure. One of the solutions is gas cycling/injection into the reservoir.The main objective of this work is to study Sarkhun reservoir, which is a gas-condensate reservoir and is located in southern Zagros. In this study gas injection has been investigated in a gas condensate reservoir to increase the condensate recovery factor and capability of different injection gases (N2 and CH4), has been compared through different injection schemes. The injection schemes considered was different injection rates. The results show that gas cycling cause increment of liquid condensate recovery. In 15MMSCF methane flow rate, reservoir goes to one phase region but for N2 injection reservoir never goes to one phase region. Also results show that methane injection give better result because of its immiscibility in reservoir fluid.

Keywords:

Gas condensate , reservoir , gas recycling , injection