TECHNOLOGY Kyrgyzstan starts up its first refinery

Kyrgyz Petroleum Co. started up Kyrgyzstan's first refinery, this 10,000 b/d topping plant, last October. The refinery produces gasoline, diesel, and heavy fuel oil for sale within Kyrgystan.

• Crude, product properties [21489 bytes]

The refinery is located in the western Kyrgyz city of Jalalabad.

Kyrgyzstan is a mountainous country between Kazakhstan and China in central Asia. Its area is approximately 76,000 square miles (smaller than South Dakota), and it has a population of about 4.5 million.

Before construction of the Jalalabad refinery, all finished petroleum products were imported from neighboring countries. Kyrgyzstan's demand for finished products is about 40,000 b/d.

The new refinery was designed and constructed by Petrofac of Tyler, Tex., on behalf of Kyrgoil Corp., Calgary. Kyrgoil is a partner with the Kyrgyz state oil company, Kyrgyzsneft, in a venture called Kyrgyz Petroleum Co. (KPC).

KPC has undertaken restoration and continued development of the oil fields in Kyrgyzstan's Fergana basin, in addition to the refinery project. The company also has marketing rights for finished products within Kyrgyzstan.

Seven potential hydrocarbon basins have been found in Kyrgyzstan. The Fergana basin is in the southwestern part of the country, and extends into neighboring Uzbekistan and Tajikistan. It is located in a large valley, surrounded on all sides by high mountains.

Crude oil has been extracted from Fergana since the days of Genghis Khan, when surface oil was used to grease cart wheels. The main oil fields in the basin were discovered during and shortly after World War II.

Currently, the Fergana basin is the only area in Kyrgyzstan producing oil and natural gas. There are oil pipelines in the Fergana Valley, but oil is not transported out of the valley. Before start-up of the refinery, products were imported into Kyrgyzstan primarily by rail from Uzbekistan, Kazakhstan, Russia, and Turkmenistan, and crude oil was trucked out.

The KPC refinery project was initiated in late January 1996 and completed on a turnkey basis in just 9 months. Local labor and equipment were utilized to the maximum extent possible to meet the schedule. Tanks were constructed by a subcontractor from neighboring Kazakhstan.

The refinery comprises: a hydroskimming (atmospheric distillation) section, diesel steam stripping, gasoline blending, and utilities and off-sites, including steam generation, power generation, tank farm, truck and rail tank-car loading and unloading facilities, crude inlet pipeline, high-voltage power line, substation, air compression, laboratory, and maintenance facilities (Fig. 1 [33212 bytes]).

The refinery is operated by Petrofac under contract to KPC.

Process description

The KPC refinery is designed to process 10,000 b/sd of 30.1° API Kyrgyz crude. Crude fractionation is accomplished in three towers: crude distillation, naphtha stabilization, and diesel stripping.

Because the crude is sweet (0.4 wt % sulfur), sulfur removal and sweetening facilities are not essential. The refinery yields and crude oil and product properties are shown in Table 1.

Crude oil is pumped to the refinery on flow control by crude charge pumps located near the crude oil storage tanks. About 2 vol % fresh water is added to the crude to prevent salt deposition in the exchangers. Desalting is performed in an electrostatic unit. Crude leaving the desalter is further preheated by exchange with hot diesel. Additional preheat is added by exchange with hot resid.

The crude charge is split into two parallel streams. The total crude charge and its division into the two streams is controlled by flow control to two crude feed heaters. The heaters raise the temperature of the oil before it enters the flash zone of the crude tower.

The heaters are equipped with burners fired by resid offgas. A small amount of steam is used to atomize the resid.

The crude heaters are equipped with steam superheating coils in the convection sections. The superheated steam is then fed to the crude tower and diesel stripper. Partially vaporized crude from the heaters is fed to Tray No. 4 of the crude tower.

The superheated steam is fed below Tray No. 1 of both the crude tower and diesel stripper to increase the volatility and to strip light material from the unvaporized portion of the crude and diesel as it flows through the bottom stripping trays of the towers. The overhead vapor from the tower is cooled in an overhead condenser.

The condensed overhead product is collected in an overhead accumulator. Any uncondensed vapors are discharged through pressure control to the offgas system during normal operation, or to the flare during a unit upset.

Naphtha flows through a packed section of the naphtha stabilizer, where light gases are separated and recycled back to the inlet of the crude tower overhead condenser. Heat to the naphtha stabilizer is provided by steam.

Stabilized naphtha flows through a cooler, then to storage tanks under level control. The stabilized naphtha is blended with tetraethyl lead to boost octane and produce A-76 gasoline.

Resid is withdrawn by level control and heat-exchanged with the crude. A part of the flow from the outlet of this exchanger is pumped by the fuel oil fire pumps and used as fuel for the burners of the heaters and boilers. The rest of the flow goes through a cold resid/crude exchanger, then to resid storage.

Diesel is drawn from the crude fractionator and fed to the diesel stripper. Superheated steam is fed below Tray No. 1 of the diesel stripper.

Diesel is drawn from the bottom of the stripper on level control and pumped to a hot diesel/crude exchanger, then to a cold diesel/crude exchanger. A substantial amount of diesel is sent back as reflux to Tray No. 14 of the crude fractionator to recover heat from the process.

Project execution

The challenging 9-month schedule for the Kyrgyzstan refinery project was met by maximizing use of modular design and construction techniques. Modular construction allows the control of quality and schedule by maximizing use of fabrication shops, which are a controlled environment. This is especially beneficial in the case of fast-track projects in remote areas such as Kyrgyzstan, where skilled labor and materials are scarce.

The modular refinery was designed, fabricated, assembled, and trial-fit by Petrofac in Tyler. Prefabrication and preassembly were used as much as possible. Items which did not easily lend themselves to modularization or preassembly-such as the crude tower and heaters-were prefinished as much as possible before shipment.

The modular facilities and other materials were shipped from the Port of Houston in three shipments. The first left the U.S. in early May 1996. Two other shipments followed in June and July.

The first shipment included some of the modules, the crude tower, and the heaters. The second shipment included the balance of the modules, while the third contained bulk materials and utilities systems.

The materials were shipped to St. Petersburg and Kotka, Finland. They were then shipped by rail to Jalalabad. The logistics were complicated by the many border crossings required by the rail route, which traversed Russia, Kazakhstan, Turkmenistan, Uzbekistan, and Kyrgyzstan.

Material began arriving at the site in early July. Site preparation work and tank farm construction began in late May. Field construction activities-including equipment installation, tank farm construction, road construction, and installation of loading facilities, buildings, utilities systems, and all other works-were completed in late September.

The Kyrgyzstan refinery has been operating successfully since October. Kyrgyz Petroleum plans to expand the refinery in the near future, once crude oil production increases to the point where crude supplies will sustain the additional capacity.

The Author

Gordon McLeod is vice-president of business development for Petrofac LLC. He has served Petrofac in various capacities over the last 14 years, including vice-president of engineering for Petrofac International and supervisor of instrumentation and electrical engineering. McLeod joined Petrofac in 1982. Previously he worked for Exxon Co. USA at its Baytown, Tex., refinery, and for Separex Corp. He is a registered professional engineer in Texas and Louisiana and has a BS in electrical engineering from New Mexico State University.

Copyright 1997 Oil & Gas Journal. All Rights Reserved.