Dependence On Oil To ContinuePublished: April 1, 2014
Mechanical and Aerospace Engineering interim chair Jalal Torabzadeh’s expertise in enhanced oil and gas recovery processes is supported by solid fact.
“There will be dependence on petroleum for the foreseeable future,” said the member of the university since 1986. “That is true whether we are talking about solar, wind, biomass or any kind of alternative energy source. This is especially true for transportation. Currently, about 60 percent of our energy consumption still comes from oil and gas and this trend will probably continue for the next couple of decades and it will stay that way until a meaningful substitute is found.”
Torabzadeh’s conclusions are backed by professional experience as a reservoir engineer with the National Iranian Oil Co. and as a research engineer for the Chevron Oilfield Research Co. The winner of many awards from engineering professional societies including the Society of Petroleum Engineers’ Distinguished member and the CSULB Nicholas Perkins Hardeman Academic Leadership Award, he earned his B.S. degree in chemical engineering from Abadan Institute of Technology in Iran and his M.S. and Ph.D. in petroleum engineering from USC.
“When we talk about oil and gas reservoirs, we are not talking about pools of oil and gas,” he said. “The oil and gas are in porous spaces in sedimentary rocks. When there is pressure from one side or the other, the oil moves. An oil reservoir resembles a tray of marbles. Put oil in that tray and the liquid occupies the porous spaces between the marbles. What oil and gas recovery processes do is to push it from one side to another.”
That push can become a shove when the oil is deep enough. “When an oil or gas reservoir is discovered, the surface of the Earth is often several thousand feet above, and, in some cases, even 30,000 feet above,” he explained. “That depth represents tens of thousands of pounds per square inch pressure. The term “primary recovery” refers to the production of oil/gas due to the force by the natural energy stored in the reservoir (high pressure) which is released when a conduit is established between the reservoir and the surface.”
But after years of production and the natural energy of reservoir are depleted, the pressure drops and there will be no movement of the fluids. “When the natural energy of the reservoir is depleted, it is time for secondary recovery methods,” he explained. “The reservoir will be subjected to the injection of gas, which can be introduced into one well to help produce oil from another well. The same effect can be created using water but the mechanism is not very efficient due to big difference in mobility of oil and water. Additionally, due to the nature of sedimentary rocks and wetting characteristics, the oil sticks to the porous surfaces or is trapped in tiny pore channels. It acts like grease that sticks to dishes and needs to be washed by a detergent solution.”
The next step in oil recovery known as “enhanced oil recovery or tertiary method” is the use of chemicals. “Combined with water, these Surface Active Agents (Surfactants) clean out the residual oil by acting like detergent,” he said. “The primary process of using the reservoir’s natural energy recovers only 25-30 percent of the stored oil. The primary recovery must be supplemented by secondary and tertiary methods referred to as `improved oil recovery methods.’”
Long Beach, Wilmington and Signal Hill demonstrate oil recovery in action.
“In the Wilmington fields, one of the largest reservoirs in the U.S. has been producing close to century. It has gone through the primary and secondary recovery process and still producing through use of chemical-floods, hot water injection and-steam floods to this day,” he said. “Look at Signal Hill which still uses pumps because the natural energy of the field is depleted. Even a field that has produced as long as 100 years still has more than 50 percent of its original oil in place.”
The pressure for more and more energy isn’t going away any time soon. Being the primary energy sources for a century, oil and natural gas will still be the main players in fulfilling the energy demand of the world for a foreseeable future.
“For instance, after decades of research and development, change in auto design and manufacturing and investment of billions of dollars, less than 5 percent of the cars in California (the largest user of alternative energy fueled-cars in the U.S.) use alternative fuels,” said Torabzadeh. “That leaves over 96 percent of trucks and cars still using gasoline, diesel fuel or natural gas. Electric cars are limited by their mileage and power. How can heavy vehicles like trucks operate on electricity? The batteries of electric cars should be charged daily/nightly. Where that energy (power) is coming from? Still, mostly from power generated by power plants burning oil, gas or other fossil fuels.
“Petroleum resources are scarce and limited,” he added. “We should use this energy resource wisely and efficiently and not waste it. Unfortunately, till now a major percent of oil produced is burnt. Oil is used in production of literally thousands if not millions of other products from medicine to household items, cloths, construction materials, space-related materials; computers, you name it. We should not burn it.”