Abstract
This paper investigates the performance of a pilot linear Fresnel steam generator, for Enhanced Oil Recovery (EOR), under the climatic conditions of Kuwait. Simulation results are compared to previously published results from a similar pilot installation in Miraah of Oman which delivers 50 tonnes of steam per day.
A desired 7 MWth peak power pilot plant is assumed in this work which will produce 80% quality steam at 110 bar and 300 ° C, matching typical EOR specifications. Simulation performed using System Advisor Model (SAM), developed by NRL, based on historical data of Direct Normal Irradiance (DNI) of Kuwait. Given that the heating and pressurization of the subterranean reservoir typically transpires over a period of many months, EOR process is not sensitive to the timing of steam injection, and thus we can assume no steam injection during the periods with no sun. Linear Fresnel collectors have been assumed, which are like parabolic mirrors. Two more assumptions are worthy of comment. First, the SAM model baseline assumptions included 5% soiling on mirrors and 2% average soiling on the receiver envelope.
In a typical EOR application, to maintain steam injection around the clock, solar steam is injected during the day and steam produced by natural gas is injected at night. If the rate of steam injection is held constant, gas consumption is reduced by up to 25%. By injecting more steam during the day and less at night, gas consumption can be reduced up to 80% without the need for costly thermal storage; the reservoir itself acts as a primary thermal storage medium. The simulation shows that a peak power of 7 MWth can be achieved with an average output of more than 50 tons of steam per month from May to August and 10 tons/month for the rest of the year; a total of 517 ton/year. The simulated system requires a total land area of 5.2 acres and can eliminate 44,698 ton of CO2 emission per year.
To the best of our knowledge, a few studies have been published for Kuwait, which is pursuing a national objective to produce 4 million b/d of oil by the year 2020. This target may be achieved sustainably with heavy oil development using various techniques like unheated-water flooding, hot water flooding, steam flooding, and cyclic steam stimulation. The objective of this study is to investigate the later technique under the local climatic conditions.
