Natural Gas Storage
Mam-Beigi said a plan for storing natural gas produced by Shourieh-D started in 2010 after primary feasibility studies were conducted.
“In this project, as a support for gas supply to northern provinces, gas storage is done during eight hot months of the year to be used during cold months. By operating Shourijeh UGS plan, Iran will become the first in the Middle East and the fifth in the world in terms of underground gas storage capacity,” he said.
Mam-Beigi also drew a parallel between natural gas injection into Shourijeh storage facility during the first five-months of the current year and that of last year, saying: “During last [calendar] year’s five months, 722 mcm of gas was injected into this storage facility. This amount has exceeded 1 bcm for the current year.”
Regarding the process of gas injection into Shourijeh-D, he said: “If we can inject 10 mcm/d of gas to this storage facility as planned during the first eight months of the year we will be most probably able to withdraw 20 mcm/d of this gas in cold seasons of the year.”
In the current calendar year, approximately 70% of gas injection into Shourijeh has materialized. In the peak shaving, 14 mcm/d of gas is expected to be recovered from Shourijeh storage facility.
Mozdouran reservoir was discovered in 1968. It started production in late 1983 after more wells were drilled and installations were designed and built for sour gas treatment at Shahid Hasheminejad refinery.
Mozdouran contains high-pressure sour gas. Due to its 3.5% sulfur and 6.5% carbonic gas contents, this sour gas is very corrosive in wells, installations and pipelines. Furthermore, since sulfured hydrogen is acutely poisonous its release into the environment is very dangerous to human being and the environment.
Safety and Anti-Corrosion Requirements
Maximum carefulness, discipline, vigilance and knowledge of recovery from this reservoir and similar ones are pretty essential. Over the past 22 years, this reservoir has experienced no specific problem or fatalities. The pipeline and installations are in ideal conditions in terms of interior and exterior corrosion although their lifecycle is approaching its end.
Mam-Beigi cited precision, observation of international standards in choosing and consuming commodities for the completion of sour gas wells and building installations and pipelines in contact with sour gas, observing welding standards, removal of stress, conducting pressure tests throughout installations, workover or replacement, carefulness in choosing anti-corrosion material and correct use of them in injection into wells and wellhead continuous injection into production system, registering the properties of all pipelines and installations during periodic thickness measurements, timely installation and replacement of corrosion monitoring coupons and conducting rectification measures in the shortest possible time, monitoring the amount of water produced from wells and controlling the salt content of gas production and transmission facilities and the continuous monitoring of cathodic protection systems as the effective factors in preventing the corrosion of installations and pipelines.
According to him, preservation of valves and the safety systems of wells and installations, continuous education of the staff and precise supervision over the safe performance of all operating and reparation staff at all levels and regular inspection and preventive reparation are among other factors that would prevent the corrosion of installations.
Gonbadli gas field, which is situated 25 kilometers southwest of the city of Sarakhs, near the border with Turkmenistan, became operational in 1986. Of a total of 9 wells dug in this reservoir, three wells are producing 1.1 mcm/d of gas at best. Nearly 91% of the gas contained in this field was recovered by March 2006. Since this gas filed is jointly owned, production from it is under way non-stop and by operating pigging. The gas contained in this field is sweet and contains less than one percent of carbonic gas.
13% Share in Gas Output
Mam-Beigi said EOGPC accounts for 13% of gas production in the country, adding: “This amount of gas is produced under the toughest operating conditions because the gas in this area contains a high amount of H2S, and there are few reservoirs in the world with such production conditions. In a bid to prevent corrosion, every year from May to September, all installations, wells and gathering centers are tested so that weaknesses would be identified and to ensure the necessary reparations are made.”He said the average annual production from Mozdouran, Shourijeh-B, Shourijeh-D and Gonbadli reservoirs stood between 1 and 1.1 bcm.
ICOFC has assigned EOGPC with the following missions: Implementation of contracts about steering production, processing and transfer of oil and gas and similar products, maintenance, optimization and overhaul of all major and related facilities (production units, pipelines, gas pressure booster stations, wellhead equipment, electricity, telecom and water installations, roads), conducting all necessary modifications to subsurface facilities (workover of wells, development of major and related facilities), drilling new wells in the operating fields in coordination with the main company and conducting field development projects and implementation of surface and subsurface facilities.