Comprehensive Comparison Between Using the Main Big Separator in the Power Plant Site and Two Small Separator in the Near of Wells in Each Sites for 25 MWe Power Plant in Sabalan, Iran

Abstract

The Sabalan geothermal field is a high-temperature area under development. Geothermal exploration was started in 1975 by the Ministry of Energy of Iran. After revolution in 1979 in Iran, it was stopped, and it was started again in 1998 by SUNA – the Renewable Energy Organization of Iran. Three deep exploration wells and two shallow reinjection wells were drilled in 2002-2004 in three sites A, B and C, by SUNA beside the preparation of two sites D and E for new drilling. This area is about 16 km southeast of the town of Meshkinshahr. There is an overall potential for the generation of about 200 MWe over the greater prospect area. SKM (main consultants 1998-2006) assesses that commercial geothermal power generation can be achieved at Sabalan at a levelised cost of electricity of less than 5 USc/kWh. SUNA is planning to drill thirteen new wells, and build a 50 MWe power plant, when these wells will be drilled. As the first part of project, SUNA will build a pilot power plant in order to confirm, that a geothermal power plant can be operated in Iran. Moshanir was the consultant for civil work 1998-2006 and since 2006 the consortium of Moshanir, EDC and Lahmeyer was selected as main consultant for geothermal field and in this part, the new drilling was started since of 2008 till 2011. In this phase one of the pervious well in the sites B was be deeper and 6 deep wells were drilled in three sites D, E and C. Now a 5 MWe power plant is under building near to site D. In this paper, a power plant with capacity of 25 MWe in site A is assumed, with steam from production wells on pads D and E, and with brine water reinjection at wells on pads B and C. Then pipelines will be designed for transmission two-phase flow from site D and E to site A in one line and separate in Site A with a big separator then assume one separator in each site, D and E, than transmission steam and water from Site D and Site E in two separate lines to site A, then a comprehensive compare will do done between two methods for transmission and separation system, then discussed about the best method based on the minimum cost and minimum drop pressure.