Processing Iran moves to beef up downstream operations

Feb. 26, 1996
Bob Tippee Managing Editor- Economics and Exploration Laval Refinery LPG Recovery and Treating System [41522 bytes] The two gas processing plants NIOC plans would add to a network that handles associated production from southwestern Iran's onshore oil fields. Iran's campaign to restore its petroleum industry includes addition of gas processing and refining capacity. Two project proposals by National Iranian Oil Co. (NIOC) call for construction of gas processing plants designated NGL
Bob Tippee
Managing Editor-
Economics and Exploration
The two gas processing plants NIOC plans would add to a network that handles associated production from southwestern Iran's onshore oil fields.

Iran's campaign to restore its petroleum industry includes addition of gas processing and refining capacity.

Two project proposals by National Iranian Oil Co. (NIOC) call for construction of gas processing plants designated NGL 1200 and NGL 1300 (see map, OGJ, Feb. 19, p. 19).

The NGL 1200 plant would treat and recover liquids from associated rich and sour gas from onshore Gachsaran oil field in the southern part of Southwest Iran's main oil producing region.

Processing and treatment facilities would be located near Gachsaran's high pressure compressor station.

NIOC estimates liquids output at 28,000 b/d from 292 MMscfd of sweetened rich gas feed at 525 psia of pressure with a temperature of 125F.

A 300 m, 20 in. pipeline would be needed to transfer rich sour gas from the Gachsaran slug catcher to the NGL 1200 sweetening unit. The project also would require a 700 m, 20 in. pipeline to carry lean gas from the processing unit to the high pressure compressor station.

Other pipelines would be needed to carry sweet NGL from the new plant to the existing NGL pipeline network, including 40 km of 10 in. line between the new plant and existing plant NGL 900 and 44 km of 12 in. line between existing plant NGL 1000 and the main transmission pipeline.

The liquids eventually would flow to the Bandar Imam Petrochemical Co. complex at Bandar Imam Khomeini (formerly Bandar Shahpur) on the northern end of the Persian Gulf. The company recently commissioned a 290,000 metric ton/year ethylene dichloride plant and associated vinyl chloride monomer and polyvinyl chloride plants at the complex (OGJ, Jan. 1, p. 51).

The NGL 1300 plant would provide feedstock to a processing unit at Bandar Mashar, 17 km northeast of Bandar Imam Khomeini. It would process associated gas from Rag Sefid, Binak, and Bibi-Hakimeh oil fields in the southern part of Iran's oil producing region.

Located near the Bibi-Hakimeh high pressure compressor station, south of the Gachsaran unit, the single train plant would process 175 MMscfd of rich gas and 2,500 b/d of NGL leaving the station's slug catcher at a pressure of 564 psia and temperature of 120 F.

Lean gas from the plant would be cycled back through the high pressure compressor station for injection into the Bibi-Hakimeh reservoir. Output liquids, estimated at 19,000 b/d, would move through a new 28 km, 8 in. pipeline to the NGL 900 plant.

Another pipeline to be laid in this project would be 43 km of 8 in. line from NGL 900 to NGL 1000. This segment apparently would handle liquids flowing through NGL 900 from the proposed NGL 1200 plant as well.

From the slug catcher to the new plant, rich sour gas would move through 400 m of new 18 in. line and liquids through 400 m of new 3 in. line. Lean outlet gas would return via another 18 in. line.

Condensate refinery

NIOC plans to build a 70,000 b/sd condensate refinery integrated with a 230,000 b/d crude oil refinery under construction at Bandar Abbas on the Strait of Hormuz.

The condensate refinery originally was planned for the Taheri-Assaluyeh area on the coast about 400 km west of Bandar Abbas. NIOC says integration with the Bandar Abbas refinery improves the plant's economics.

About 77% of the feedstock will come from a processing plant that handles production from Nar and Kangan natural gas fields and 23% from a plant in Aghar and Dalan gas fields, all onshore southeast of the oil producing region.

The condensate refinery will have seven main units, including a single stage, 70,000 b/sd distillation unit and a 3,600 b/sd LPG recovery unit.

Basic design of the other five units was conducted under license from UOP Inc. Those units are a 14,000 b/sd kerosine hydrotreater, a 36,000 b/sd heavy naphtha hydrotreater, 36,000 b/sd continuous catalytic reformer (CCR), an 8,000 b/sd light straight run naphtha unit, and a 3,300 b/sd LPG Merox unit.

The project also will involve addition of two flare stacks and 10 storage tanks with total capacity of 700,000 bbl to those already planned for the Bandar Abbas refinery.

The 57.244 gravity feedstock condensate has 0.75 sp gr at 15.5 C. and 7.7 psia Rvp. It has negligible hydrogen sulfide, mercaptan sulfur of 94.7 ppm, and sulfur content of 0.7 wt %. Its molecular weight is 121.36, viscosity 0.58 cp at 37.8 C. and 0.32 cp at 98.9 C.

NIOC wants a lump sum contract for basic design of the distillation unit, detailed design of the whole project, procurement services, equipment supply, and construction. It seeks joint participation of Iranian and expatriate companies and wants the project to be completed within 36 months of the signing of a contract.

Lavan refinery LPG project

NIOC seeks international participation in a project to extract LPG on Lavan Island from flare gases produced offshore and from LPG base gases to become available from an expansion project under way at the 23,000 b/d Lavan refinery.

Distillation capacity at the refinery is being increased to 40,000 b/sd. In addition, NIOC is adding naphtha hydrotreating and catalytic reforming units at the refinery.

Major facilities for the proposed project include an 8.3 MMscfd compression and liquefaction system to handle the two feed streams.

Flare gases from NIOC Offshore Co. fields have maximum temperature of 50C., pressure of 0.35 kg/sq cm (g), and molecular weight of 39.2, flowing at 413.37 kg mol/hr.

The flare gases contain 3.75 mol % hydrogen sulfide, 0.14 mol % nitrogen, 2.08 mol % carbon dioxide, 20.08 mol % methane, 21.06 mol % ethane, 31 mol % propane, 6.83 mol % isobutane, 8.89 mol % normal butane, 1.79 mol % isopentane, 3.21 mol % normal pentane, and 1.17 mol % hexanes and heavier.

Treated LPG base liquids from the refinery have temperature of 40C., pressure of 14 kg/sq cm (g), and molecular weight of 53.7, flowing at 134.29 kg mol/hr.

The liquid feeds contain 0.02 mol % ethane, 31.34 mol % propane, 19.19 mol % isobutane, 49.36 mol % normal butane, and 0.9 mol % isopentane.

Other major facilities in NIOC's plan include a 265 ton/day deethanizing system, 212 ton/day debutanizing system, 170 ton/day LPG sweetening unit, 140 ton/day propane drying system, 210 ton/day butane drying system, and 350 ton/day propane and butane refrigeration system.

The company also plans to install a 115,000 bbl propane product refrigerated storage tank, a 180,000 bbl butane product refrigerated storage tank, two 5,000 bbl propane production refrigerated storage tanks, and two 7,500 bbl butane production refrigerated storage tanks.

Also planned are two 800 ton/hr propane loading pumps, two 800 ton/hr butane loading pumps, 800 ton/hr refrigerated liquid propane and butane loading facilities, and a 3,000 kw power generation and transmission system. Loading facilities can be modifications of an existing jetty or new buoy moorings.

NIOC is turning to outside sources for help in its planned expansion of the complex refinery at Shiraz from 40,000 b/sd of distillation capacity to at least 60,000 b/sd.

NIOC says growing demand for petroleum products around Shiraz makes the expansion necessary.

The project would include installation of an atmospheric distillation unit with capacity of at least 20,000 b/sd and a vacuum distillation unit with capacity of 15,000 b/sd.

Other units to be added are a 10,000 b/sd heavy and light straight run gasoline hydrotreating unit, 6,500 b/sd CCR, 10,000 b/sd hydrocracker, 15 MMscfd hydrogen production unit, 6,000 b/sd LSRG isomerization unit, 6,000 b/sd kerosine and gas oil hydrotreating unit, 2,000 b/sd LPG recovery and treating unit, 5 MMscfd fuel gas amine treating unit, 15 cu m/hr sour water unit, 20 ton/day sulfur recovery plant, and 2,500 b/sd lube oil production unit.

At present, the Shiraz refinery produces as much as 1,600 b/sd of LPG, 6,400 b/sd of regular gasoline, 400 b/sd of super gasoline, 810 b/sd of JP4 jet fuel, a total of 2,025 b/sd of other aviation fuels, 3,500 b/sd of kerosine, 9,000 b/sd of gas oil, 7,000 b/sd of fuel oil, 7,000 b/sd of bitumen, 12 tons/day of sulfur, and 2,800 b/sd of fuel and wastes.

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