Latest Iran Gas Storage Projects
Nasrabad salt structure in Kashan, Shourijeh field, Bankul, Baba Qir and Qezel Tappeh are among the most important underground natural gas storage projects in Iran. The following is a review of the latest status of the above projects.
Nasrabad Salt Structure
Ali Teimouri, director of underground natural gas storage projects, said: “Given the exploration activities conducted in Kashan’s Nasrabad salt dome, our analyses brought us to a structure which could be worked upon.”
“Following implementation of geological studies, we went step by step until we were assured about the potential for developing this structure. As the project had been defined in five phases and there was no previous experience of salt reservoir development in the country, we hired an internationally recognized company with good experience in salt structure development,” he said.
Teimouri said that in the next phase, the drilling of a 2,000-meter-deep well was started in Kashan’s Nasrabad salt structure. Coring is currently under way at the depth of 1,400 meters.
“By analyzing the chemical and geo-mechanical properties and the purity of salt we can assess whether or not the structure is suitable for natural gas storage. Having finished three phases of this project, we are following up on phases 4 and 5,” he said.
Teimouri said the findings of the studies currently under way would be announced in coming months, adding they would be decisive for the project.
He expressed hope that the Nasrabad structure would have a significant share in the future of gas storage in Iran.
28 Wells Drilled for Shourijeh Development
Mohammad Zaman Jokar, director of natural gas storage development project at Shourijeh site, said: “One of the plans envisaged to make up for gas shortages in the northeast is to develop gas storage in the Shourijeh field.”
He said that following the positive feedback from the first phase of the Shourijeh gas storage project, the second phase is under way, which would require the drilling of 28 wells and construction of gas gathering, as well as injection and treatment facilities.
Jokar said unlike the first phase, which was done through EPC and was handled in upstream by National Iranian Oil Company (NIOC) and in downstream by National Iranian Gas Company (NIGC), in the second phase, full authority has been delegated to NIGC, and the project will be a BOT one.
After the technical assessment of contractors and the conclusion of tender bid, the successful bidder would be named.
The successful bidder (investor) will agree to supply treatment facilities and gas injection compressors, drill 28 wells, lay out gas gathering and transmission lines and build necessary utilities over three years and bring the project into operation. Based on the tender documents, the investor will have control over the facilities for 20 years, during which the contractor will recover costs. After the startup of the project, during the first eight months of the year, 4.5 bcm of gas would be injected to the Shourijeh storage facility to be recovered and consumed during peak shaving in cold months.
Bankul, Baba Qir Project Due in 2023
Mehdi Yousefi, head of construction and installation for underground storage projects and manager of the Bankul and Baba Qir project, said: “Initial assessment of exploration drilling operations on the Bankul and Baba Qir fields was done in 1973 in order to estimate volume of oil reserves. After one well was spudded in Bankul and two wells in Baba Qir, the wells were declared mothballed due to the gas deposits of the reservoirs.”
Yousefi said that Natural Gas Storage Company conducted pre-feasibility studies in 2017 and it was decided that an appraisal well be drilled to study the possibility of gas storage in the Bankul field.
He added: “Also, an appraisal well should be drilled to assess the possibility of gas and condensate recovery in the Baba Qir field. NIGC approved budget allocation for this operation in March 2019 after follow-up by the Iran Gas Engineering and Development Company.”
Yousefi said gas storage feasibility studies had begun in the Bankul field, which would be concluded by 2023. And for the Baba Qir field, seismic testing data is being provided and the feasibility study would be over by early 2024.
Qezel Tappeh Storage
Hossein Sheikhzadeh, director of feasibility study for natural gas storage in the Qezel Tappeh field, said: “The concentration of Iranian hydrocarbon reservoirs in the tropic zones of the southern half and the lack of gas storage facilities to support populated and cold areas in the north and northeast of Iran, GSC was prompted to carry out technical and economic assessment and screen structures for natural gas storage with a view to finding a suitable place for gas storage, mainly in the northeast and Gorgan Plain.”
He said the outcome of these comprehensive studies was identifying and choosing several fields, including Qezel Tappeh and Gonbad Kavous, for underground natural gas storage.
According to Sheikhzadeh, the next step would require acquisition of necessary permits and delegating authority to NIGC over this reservoir. He said a plan was adopted to study the feasibility of storage in this field.
The upstream data from the fields was received from the Directorate of Exploration of NIOC and Khazar Exploration and Production Company (KEPCO), and the prefeasibility study was carried out by the University of Tehran. Finally, this field was proposed as the option for underground natural gas storage.
Sheikhzadeh said in the first step, one appraisal well was being drilled and completed so that analyzing the output data including geological data, petrophysical logs, cores and well tests would be used for the development of the field.
He said that the output from these studies would provide two scenarios to decision-makers.
“In the first stage and in case of production potential in the reservoir, planning would be made for production and recovery from Qezel Tappeh. In the event of negative production, the feasibility of storage would be put on the agenda,” he said. “What matters in the stage of well drilling and reservoir assessment is the very special conditions of the appraisal well. We are faced with complicated conditions in this project, including depth, high temperature and pressure. Drilling here is totally different from drilling in other wells, and input data shortages and insufficient knowledge add to the drilling and prospective development problems.”
In terms of logistics and operation, displacing drilling rigs and equipment from north to south and the difficulty of services, as well as concerns over the supply of commodities and equipment would add to complications, he said.
He added: “We will try to overcome these obstacles by using facilities available and requesting commodities from other oil companies. Special technological complexities and the depth of engineering, knowhow and commodity supply issues in this project become more serious in light of uncertainties and the changing behavior of the reservoir. In order to resolve this problem, we have forced contractors to hire foreign consultants so that the project would come online at high quality, optimal cost and on schedule.”
Sheikhzadeh said: “We are hiring a qualified consulting company with experience in oil exploration and extraction.”
He said: “We should not forget that Gorgan Plain where the Qezel Tappeh field is located is an exploration-extraction objective for NIOC. Project data could be of great help for both the NIOC Directorate of Exploration and KEPCO that are looking for hydrocarbon exploration potential in the north.”