Smart water injection

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Client: national iranian south oil co.

Oil recovery by waterflooding from Iranian carbonates reservoirs is repeatedly reported to be a challenge because of low permeability of matrix blocks, natural fracture networks, and low water-wetness of the rock (or negative capillary pressure and consequently low rate of spontaneous imbibition of water from fracture networks into the matrix blocks). This has been the reason for waterflooding to not be implemented widely in Iran.

With the new understanding about the EOR potential of seawater/modified seawater to improve the water-wetness of carbonate rocks at high temperatures, NAED has suggested the client to have a new look at the water flooding (and now as a wettability modifier).

The project is divided into two parts:

1. Evaluation of smart water and it’s EOR prize in the field

2. Monitoring of a waterflooding project.

In the first part, the focus is on the introduction of a general methodology on how to screen the candidate Iranian carbonate oil reservoirs for a ‘smart-water’ flooding for maximizing tail production with emphasis on no chemical additives. The second part of the project is about monitoring of reservoir production and injection that has been recently considered as one the main legs of IOR/EOR programs. This is being considered as a necessary step to increase the chance of success. A variety of monitoring programs have been employed, however, NAED has suggested use of 4D seismic due to its full and 3D coverage of reservoir. Our scope of work is as follows:

Part One: Evaluation of smart water

Oil and rock characterization (fast screening of potential)

Preliminary EOR potential of smart water

EOR potential of smart water in sector and full field model

Optimization of the process by adjusting the drainage strategy of the reservoir

Part Two: Monitoring

Rock and puid physics

AVO modelling and seismic inversion on the carbonate reservoirs

4D seismic feasibility study on the carbonate reservoirs

Elemental sulfur deposition study (a sour gas field in persian gulf)

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Client: petropars / iranian oil offshore company (iooc)

Production from an offshore field located in Persian Gulf is expected to be challenging, not only due to its HPHT nature, but also because of high H₂S content and presence of dissolved elemental sulfur in the reservoir gas. Once the pressure, composition and specially temperature changes over production life time, sulfur gets separated from the gas and become deposited and reduce productivity of the field (I.e. high temperature and pressure favors the formation of polysulfide, whereas a decrease in temperature and pressure favors the reverse reaction of polysulfide to elemental sulfur and H₂S). In the case of sulfur deposits on the tubing or pipeline wall, and its direct contact with the steel surface, aggressive corrosion will occur. It creates a serious threat to the ability to produce gas in a safe and environmentally-friendly manner.

Solvent treatment during production, start-up and shut-in is a known mitigation action to prevent sulfur to precipitate. The following services have been delivered to the project:

The following services have been delivered to Petropars and Iranian Oil Offshore Co. in this project:

PVT analysis and determine content of dissolved elemental sulfur in reservoir gas

Elemental Sulfur deposition at various operational conditions

Preliminary solvent screening and selection

Compatibility study of elemental sulfur solver with the other chemicals which may be used in the operation

South pars gas field development projects

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Client: pars oil and gas company

Nargan has been active in different phases of South Pars Gas field to deliver engineering, procurement and construction services. Engineering design of phases 13, 15,16, 19, 22, 23 and 24 have been done by Nargan and in phase 12, we have been one the key member of the EPC3 consortium. South Pars

South Pars Gas Field is the world's largest gas field which is a shared reservoir between Iran and Qatar in the Persian Gulf. The gas reserves of this huge gas field comprise about 8% of the total gas reserves of the world while the Iranian part of the field comprises almost one half of the domestic gas reserves of Iran. The Iranian portion is estimated to contain some 14 TCM of gas reserves and some 18 billion barrels of gas condensates.

Phases 12 development produces 2.5 billion cubic feet (71 million cubic meters) per day of rich natural gas, 75 million cubic feet (2.1 million cubic meters) of ethane, 80,000 barrels per day (13,000 m3/d) of natural gas condensate, 3000 tons of LPG per day plus 400 tons of sulfur per day.

Phase 13 development shall also produce 2 billion cubic feet per day of rich natural gas. Gas and input liquids are processed in this processing unit, producing the 50 MSCMPD of refined gas, 1.1 MT/year of liquefied gas for export, 80 thousand barrels/day of gas condensates for export, 1 MT/year of Ethane gas to feed the petrochemical plants.

Phases 15 and 16 development produces 2 billion cubic feet (57 million cubic meters) per day of natural gas, 75 million cubic feet (2.1 million cubic meters) of ethane, 80,000 barrels per day (13,000 m3/d) of natural gas condensate, 3,000 tons of LPG per day plus 400 tons of sulfur per day.

Phase 19 development is planned to produce 2 billion cubic feet (57 million cubic meters) per day of natural gas, 75 million cubic feet (2.1 million cubic meters) of ethane, 80,000 barrels per day (13,000 m3/d) of natural gas condensate, 3,000 tons of LPG per day plus 400 tons of sulfur per day.

Phases 22, 23 and 24 are in the north-eastern frontier of the field. The aim of phases 22, 23 and 24 development is to produce 42.5 million cubic meters (1.50 billion cubic feet) per day of natural gas, 57,000 barrels per day (9,100 m3/d) of natural gas condensate, and 300 tons of sulfur per day. The three phases also are designed to produce 800,000 tons of LNG and 750,000 tons of ethane per year.

Our services in these projects include:

Front End Engineering Design (FEED)

Detailed Engineering

Procurement Services