Published on October 11th, 2009 | by Susan Kraemer0
Ormat Supplies Recovered Energy Generation To DOE Oilfield Geothermal Test
Recovered energy generation produces electricity from heat that would otherwise be thrown away. This “geothermal” energy technology would lower carbon emissions on oil fields and from cement makers, two of the three major carbon emitters to be covered by CEJAPA energy legislation. The potential is for 5,000 MW of electricity to be harvested, and CO2 reduced; just from oil drilling operations in this country.
I contacted Jim Nations at the Rocky Mountain Oilfield Testing Center, who was kind enough to give me some additional details on the tests that I wrote about last week. The DOE testing is being carried out on a 10,000 acre oil field with over 1,000 well bores to extract geothermal energy from the byproduct of oil drilling (hot water), using a 250 KW Ormat recovered energy generator unit (pictured above).
The power system comprises a commercial standard design Ormat Organic Rankine Cycle power plant. The binary power unit uses produced hot water as the heating fluid for a heat exchanger in the Ormat Energy Converter, where a secondary working fluid, an organic fluid with a low boiling point, is vaporized. That vapor is then used to spin a turbine coupled to a generator to produce electricity.
Jim’s answers, over the jump:
(I was wrong about some things, for example, their test applies to regular oil drilling, not shale oil extraction. I had no idea that so much water was used in regular oil drilling. And the full results will be available this December, not next October.)
Is this shale oil or a regular oil well? This hot water is produced from a battery of four regular oil wells, at peak production creating about 20,000 barrels of water daily.
Do you normally reuse or discard the hot fluids? Prior to this test, the hot water produced with the oil was discarded as a waste stream after separation from the oil.
What is their composition? Hot water; about 190° Fahrenheit. Once the oil is separated from the water, the water flows through the Ormat unit, some of the heat is extracted and then the water is further cooled in three ponds. The discharge temperature is around 80 degrees F and goes into an existing watercourse. The water isn’t potable by humans, but it is eventually consumable by local flora, fauna and also livestock present in farming and ranching operations downstream.
It seems that there was a similar test begun last year September 2008, or is this the same test? That’s right, this is the same test that will now be on-going as a result of the purchase of the Ormat unit. It has been off-line from time to time due to hardware and well quality issues. We have data, just not a complete year’s worth, which is the goal of the test.
Any initial lessons learned so far? Yes, it successfully demonstrated the economic co-generation of electricity using low-temperature geothermal produced oil field water. There have been issues with equipment and hardware upgrades that required temporary shut-downs to address. These shutdowns interrupted the continuous operation of the test, so the test period has been extended in order to collect a full 12 months of operational data and to establish long-term durability.
How much energy have you harvested so far and how did you use it? Total energy produced over the first six months was 586,574 kilowatthours. The Ormat system is rated at a 250kW peak power production. Average net power production has been 180 kW. The power was incorporated to the field grid system and therefore reduced the electricity we had to buy from the power utility during those times of operation.
And so was Ormat a good choice by the DOE? I’d say so. The company is considered one of the top five geothermal innovators to watch and just won another environmental award in California for their Mammoth Pacific geothermal plant. If you’re in the oil business, there’s a conference next month to apply this kind of technology, and tax incentives to do so, in Texas.
Image: Jim Nations; Rocky Mountain Oilfield Testing Center