Extracting Optimal Path of Extraction from South Pars Offshore (With Environmental Restrictions) and Emphasis on Financing

South Pars offshore resource is the biggest gas resource of world. This offshore resource is cooperating with Ghatar and extraction from this resource is the main mean for Iran economic growth. In this paper we want to model optimal extraction path of this resource in competitive and monopoly conditions and estimate these paths. But because extraction of this resource is from the bottom of see and all of extraction and drilling process are in owner resource country which causes to environmental damages. Therefore we should improve some environmental restrictions on Investor Company، which these extractions induce Investor Company to use from some new technology in drilling and extraction process. We model environmental extraction as two scenarios and estimate optimal path of extraction and price with data 2002-2012. We do not apply environmental restrictions in estimation and apply them only in modeling. Finally we conclude that these environmental restrictions cause to improvement of optimal extraction indirectly.