Overview

Solar Thermal Enhanced Oil Recovery (abbreviated Solar EOR) is a form of Thermal Enhanced Oil Recovery

Enhanced oil recovery

Enhanced Oil Recovery is a generic term for techniques for increasing the amount of crude oil that can be extracted from an oil field...

 (EOR), a technique applied by oil producers to extract more oil from maturing oil fields. Solar EOR uses solar arrays to concentrate the sun’s energy to heat water and generate steam. The steam is injected into an oil reservoir to reduce the viscosity, or thin, heavy crude thus facilitating its flow to the surface. Thermal recovery processes, also known as steam injection

Steam injection (oil industry)

Steam injection is an increasingly common method of extracting heavy oil. It is considered an enhanced oil recovery method and is the main type of thermal stimulation of oil reservoirs. There are several different forms of the technology, with the two main ones being Cyclic Steam Stimulation and...

, have traditionally burned natural gas to produce steam. Solar EOR is proving to be a viable alternative to gas-fired steam production for the oil industry. Solar EOR can generate the same quality steam as natural gas, reaching temperatures up to 750˚F (400˚C) and 1,500 PSI.

While standard EOR injects steam into the ground at a constant rate, research conducted by leading oil producers show that variable rate steam injection has no negative impact on production levels. In effect, Solar EOR could supply up to 80 percent of a field’s annual steam requirements, by injecting solar-generated steam during the sunny hours, and a reduced amount of gas-fired steam at night or in less sunny weather or climates. This method of integrating solar EOR will displace larger amounts of gas consumption without affecting oil output.

Technology

While there are many types of solar-to-steam technologies – often referred to solar thermal

Solar thermal energy

Solar thermal energy is a technology for harnessing solar energy for thermal energy . Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors. Low-temperature collectors are flat plates generally used to heat...

 or concentrated solar power (CSP) – there are only two technologies currently deployed for Solar EOR.

Single Transit Trough (STT)

Engineered by GlassPoint Solar for rugged industrial environments, the STT architecture encapsulates the solar thermal system within a greenhouse-like glasshouse. The glasshouse creates a protected environment to withstand the elements that negatively impact reliability and efficiency of the solar thermal system.

Lightweight curved solar-reflecting mirrors are suspended from the ceiling of the glasshouse by wires. A single-axis tracking system

Solar tracker

A solar tracker is a generic term used to describe devices that orient various payloads toward the sun. Payloads can be photovoltaic panels, reflectors, lenses or other optical devices....

 positions the mirrors to retrieve the optimal amount of sunlight. The mirrors concentrate the sunlight and focus it on a network of stationary steel pipes, also suspended from the glasshouse structure. Regular, oil field quality water is carried throughout the length of the pipe, which is boiled to generate steam when intense sun radiation is applied.

The steam produced is then fed directly to the field’s existing steam distribution network whereas the steam is continuously injected deep into the oil reservoir. Sheltering the mirrors from the wind allows them to achieve higher temperature rates and prevents dust from building up as a result from exposure to humidity. The company states its STT technology can produce heat for EOR for about $3 per million British thermal units, compared with about $4 for a comparable natural gas plant in the U.S. and between $10 and $12 for other conventional solar thermal technologies.

Central Tower

Originally designed for generating electricity, central tower or power tower technology

Solar power tower

The solar power tower is a type of solar furnace using a tower to receive the focused sunlight. It uses an array of flat, movable mirrors to focus the sun's rays upon a collector tower...

, uses a field of large tracking mirrors, called heliostats, to concentrate the sunlight on a boiler filled with water that rests on a central tower. The sun’s light is reflected on the boiler to produce steam, which is used to turn a traditional turbine to create electricity. For EOR, the process ends at steam production, and the steam is pumped down an oil reservoir similar to the process deployed using Single Transit Trough. BrightSource is currently the only solar thermal provider to apply the central tower design to EOR using its Lux Power Tower (LPT) solar thermal technology.

21Z in McKittrick, California: Berry Petroleum and GlassPoint Solar

GlassPoint Solar partnered with Berry Petroleum, California’s largest independent oil producer, to deploy the world’s first commercial Solar EOR project. Commissioned in February 2011, the project is located on a 100-year old oilfield in McKittrick, California

McKittrick, California

McKittrick is a census-designated place in Kern County, California, United States. McKittrick is located northwest of Taft, at an elevation of 1056 feet . The population was 115 at the 2010 census, down from 160 at the 2000 census.-Geography:...

. Coined the Kern County 21Z Solar Project, the system spans roughly one acre and will produce approximately one million Btus per hour of solar heat, replacing natural gas used for steam generation. The Solar EOR project was constructed in less than six weeks and is this is the first installation of GlassPoint’s Single Transit Trough technology in an oil field.

Coalinga in Coalinga, California: Chevron and BrightSource Energy

In October 2011, Chevron Corp.

Chevron Corporation

Chevron Corporation is an American multinational energy corporation headquartered in San Ramon, California, United States and active in more than 180 countries. It is engaged in every aspect of the oil, gas, and geothermal energy industries, including exploration and production; refining,...

 and BrightSource Energy

BrightSource Energy

BrightSource Energy is an Oakland, California, corporation that designs, builds, finances and operates utility-scale solar power plants that deliver clean, low-cost solar energy to utility and industrial customers worldwide at prices that compete with fossil fuels.Greentech Media ranked...

 revealed a 29-megawatt solar- to-steam facility at a southern California field near Colinga. The Coalinga solar EOR project spans 100-acres and consists of 3,822 mirror systems, or heliostats, each with two 10-foot (3-meter) by 7-foot mirrors mounted on a 6-foot steel pole focusing light on a 327-foot solar tower.

BrightSource was contracted to provide the technology, engineering and production and construction services; and Chevorn Technology Ventures will manage operations of the project. The facility began construction in 2009. It was reported that Chevron spent more than its $28 million on the contract, and BrightSource has lost at least $40 million on the project and disclosed it will lose much more.

Petroleum Development Oman

GlassPoint Solar announced a deal with Petroleum Development Oman

Petroleum Development Oman

Petroleum Development of Oman is the foremost exploration and production company in the Sultanate. It accounts for more than 90% of the country's crude-oil production and nearly all of its natural-gas supply...

 (PDO) in August 2011 to build a 7MW Solar EOR system. PDO is a joint venture between the Sultanate of Oman

Oman

Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...

, Shell

Royal Dutch Shell

Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...

 and Total

Total S.A.

Total S.A. is a French multinational oil company and one of the six "Supermajor" oil companies in the world.Its businesses cover the entire oil and gas chain, from crude oil and natural gas exploration and production to power generation, transportation, refining, petroleum product marketing, and...

. The project is currently in the construction phase and will be completed by the end of 2012. Once complete, the Solar EOR facility will cover more than four acres and produce 11 tons of high temperature (312 ˚C), high pressure (1,450 psi) steam per hour. The completed project will be 27 times larger than the system deployed at Berry Petroleum’s 21Z oil field.

Market

The global market for EOR technologies was $4.7 billion in 2009 and is expected to grow at a 5-year compound annual rate of 28 percent, reaching $16.3 billion in 2014. While quickly gaining traction, it’s predicated solar EOR will have minimal impact on the market till 2015. As Solar EOR scales, oil producers will consume less gas for oil production

According to research analysts at Raymond James, Solar EOR can be done more cost effectively than using gas, even as current depressed prices. Steam represents as much as 60 percent of the production cost for heavily oil extraction. In addition to being cost competitive with gas, Solar EOR provides a hedge against long-term gas price escalation. Long-term price projections put natural gas at $5.00/Mcf, considerable higher than the 2011 forecast of $3.75/Mcf. When an oil producer invests in a solar EOR system, all costs are upfront and the standard life of the equipment is 30 years. While quickly gaining traction, it’s predicated solar EOR will have minimal impact on the market till 2015.

United States

California is a promising geography for Solar EOR with its high level of sunshine and vast heavy oil reserves. Currently, 40 percent of California’s oil production deploys steam injection for EOR and in a few years will grow to 60 percent. Together five heavy oil producers – Chevron, Aera Energy, Berry Petroleum, Plains and Occidental – consume about 283 Bcf of gas annually. This equals 1.3 percent of total demand in the United States. However, analysts say that solar EOR could replace 20 percent of the natural gas used for EOR in California. While quickly gaining traction, it’s predicated solar EOR will have minimal impact on the market till 2015.

Middle East

The Persian Gulf has exceptionally favorable insolation, which in some locations exceeds levels in the Mojave Desert, which is a factor in making Solar EOR very promising there. The other factor is less obvious but even more important: with the exception of Qatar, Persian Gulf countries are short of natural gas and actually have to import gas. The limited natural gas supplies is made worse by growing local economies that require natural gas for desalination, electricity and other industrial uses.

By using solar, instead of gas, to generate steam for EOR, Middle Eastern companies can extend their domestic natural gas supplies to higher value uses. This is especially relevant for Oman, which is aggressively pursuing EOR – for example at the Mukhaizna field, which is operated by Occidental Petroleum. Oman built a natural gas export terminal, but since its oil production peaked in 2000, the country redirected the gas for used in its EOR operations. [7] The scarcity of gas in Oman means the price there is around $10 an mcf.

History

In 1983, ARCO Solar constructed a solar steam generation pilot using central tower technology in Taft, California

Taft, California

Taft is a city in the foothills at the extreme southwestern edge of the San Joaquin Valley, in Kern County, California. Taft is located west-southwest of Bakersfield, at an elevation of 955 feet . The population was 9,327 at the 2010 census...

. The system generated one megawatt of thermal energy during peak operating conditions. Though technically feasible, the system was not cost-effective and was not replicated. [4] The ARCO pilot was the first time solar steam was applied to facilitate heavy oil recovery.