EOGPC supplies gas to Khorasan Razavi, North Khorasan and South Khorasan, Golestan, Mazandaran and partly Semnan provinces. By providing gas to these provinces, the company is playing a prominent role in the economic blossoming of the country in the energy sector.
“The top priority of this company is production, particularly in cold seasons of the year, because the EOGPC operating area is among cold areas in the country and therefore planning must be such that before cold seasons of the year start all maintenance, overhaul, and preventive activities must have been finished so that we can benefit from its production advantages and continuousness during sensitive periods of time,” Mohammad Mam-Beigi, CEO of EOGPC, told “Iran Petroleum”.
“For years EOGPC has made sophisticated plans for the technical management of the workover of wells and related services in a bid to fulfill its obligations and no problem has been created so far in this regard,” he added.
Mam-Beigi said the reservoirs operating under EOGPC administration are in the second half of their lifecycle, noting that the company’s management has made efforts to help sustainable energy supply in this area through appropriate planning.
The company has plans to ensure sustained production which is still in the exploration and appraisal phase. New fields are expected to start production in the coming years.
Holding 8% of Iran Gas Deposits
Mam-Beigi said the EOGPC’s recoverable gas reserves stood at more than 647 bcm, which make up nearly 8% of the country’s gas reserves and 17% of ICOFC gas reserves. So far 332 bcm of gas has been recovered from EOGPC fields and there still remains 315 bcm for future decades.
Meanwhile, due to development projects like increased sour gas production from Khangiran field and Shourijeh gas storage facility, as well as discovery of new fields like Tous and Attar, EOGPC is heading towards a bright future.
“In the current year development of new fields has been planned. One of these new fields is Tous which we hope will become operational soon. This field has sour gas production potential,” he said.
Referring to the development of Tous field, Mam-Beigi said: “Astan Quds Razavi has signed a memorandum of understanding with ICOFC. It has so far conducted detailed and development plans for this field and the case has been referred to the Reservoirs Committee for further examination. In my view, in case the ICOFC manages to provide the required finance, it would be able to develop this field on its own.”
He announced the existence of Kashfroud gas layer beneath Mozdouran layer in Khangiran field, saying: “In the past, two wells were used in this layer temporarily. The results of tests indicated that this layer holds very high-pressure gas. Production from this layer is expected to be realized thanks to plans devised by the Exploration Directorate of National Iranian Oil Company (NIOC). Based on these conditions, we will be able to have one operating gas field in this part of the country for years.”
Khangiran Gas Supply
Khangiran gas field is located in Khangiran area and 25 kilometers northwest of the border city of Sarakhs. It has three separate gas reservoirs (Mozdouran, Shourijeh B and Shourijeh D) which lay one another. The one on the top is Shourijeh which is divided into layers A, B, C, D and E. At present, only the layers B and D contain sweet gas.
Mam-Beigi said the most dangerous sour gas in the petroleum industry currently exists in Khangiran operating area.
“The sour gas in Khangiran area with H2S content of more than 36,000 ppm is among the most dangerous sour gases in the petroleum industry of Iran and the world. With a primary wellhead pressure of 5,400 pam, it has special design in terms of safety and operation,” he added.
Regarding tough weather conditions in Khangiran operating area, he said: “The geographical conditions of this area are such that the temperature varies between 50 degrees Centigrade in summer and minus 25 degrees Centigrade in winter.”
“Furthermore, the absence of desirable fauna, recent drought and quick sands moved by strong monsoon winds are among other environmental problems in this area,” he added.
Shourijeh-B reservoir, which was discovered in 1967, started production in 1974 by supplying gas to the city of Mashhad. Currently, 50 wells of the reservoir are producing up to 1.5 mcm/d of gas. After condensates are separated by wellhead separators, the remaining gas is delivered to an old dehydration plant. The recoverable gas reserves of this reservoir are estimated at 16.141 bcm, nearly 72% of which was recovered by March 2006.
Shourijeh-D reservoir was discovered in 1987 and started production the same year. Like Shourijeh-B, Shourijeh-D’s gas lacks sulfured hydrogen and is known as sweet gas. But due to carbonic gas impurities, it corrodes pipelines and installations. Therefore, in a bid to contain corrosion, special substances are injected into the wells.
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.
By Forough Gashtasbi
Courtesy of Iran Petroleum Monthly