Modeling of subsidence in south Pars as field using analytical and semi analytical methods

Exploitation of hydrocarbon reservoir would cause decrease in pore pressure and increase of effective stress applied to reservoir rock, which result in compaction of reservoir. If the reservoir compaction exceeds certain limit, the overburden rocks of reservoir due to their weights begin to subside. With respect to the importance of South Pars gas field which belongs to Iran and Qatar, calculation and modeling of field surface subsidence is very important. In this paper for determination of South Pars Gas field subsidence, at first, the reservoir compaction with use uniaxial compaction theory was calculated and then the effect of this compaction on the field surface with use analytical and semi analytical method was modeled. The amount of South Pars reservoir compaction at the end of production period reached up to 0.5 meter and according to the results of two subsidence modeling methods, maximum subsidence value will reach to over 0.6 meter.