Thermal Systems: Economically extracting significantly more oil from current oil reservoirs
One of the fascinating things about my job is contemplating questions like: What will the future energy mix look like? This is difficult to predict but it is fair to argue that oil will still be in the mix for many years to come and this will be extended by Enhanced Oil Recovery (EOR) technologies. GE is likely to be providing key equipment in the EOR application area to enable these operations. Enhanced Oil Recovery (EOR) will enable old oil reserves to continue to provide the future oil demand in balance with coal, natural gas and renewable sources, as long as the economics of the methods are better than the world oil price.
Power production and energy security play a pivotal role in international politics and world economics. The earth has limited natural energy resources that take longer to be produced than the current rate of consumption. These resources are therefore considered non-renewable, for example fossil fuel hydrocarbon reserves. Many nations are aggressively growing energy from renewable sources such as wind and solar.
Early in the 20th century coal was the dominant energy source but late in the 20th century oil took over this position. Natural gas, biomass and hydrogen are expected to grow significantly in the 21st century. Oil is expected to remain an important portion of the future energy supply. However, conventional oil production from known deposits is declining due to the increasing age of the wells. Technology improvements such as deep water drilling, fracturing and horizontal drilling enable oil recovery that was previously not viable. Extraction from tar sands and tight oil is increasingly economically viable. However, other energy sources, such as shale gas and coal bed methane, also compete more vigorously with oil.
Oil production generally has three phases and in each phase more of the original oil in place (OOIP) is able to be extracted. Initially the oil generally gushes to the surface under its own pressure. With time, usually many years, this flow slows due to a declining driving force. The secondary phase is when the oil needs to be assisted out of the ground using artificial lift systems or injecting gases or fluids that maintain the pressure in the well. Eventually a stage is reached where pressure alone is unable to extract further oil. Then the oil properties or interaction between the oil and the rocks need to be changed – this is the tertiary phase also called enhanced oil recovery (EOR). Gas injection, thermal, chemical and microbial methods change the viscosity of the oil, the driving fluid viscosity or surface tension. The dominant technologies in EOR are CO2 flooding and steam injection. Hydrocarbon flooding, low salinity water, nitrogen and in-situ combustion are smaller and some are emerging. Low salinity water is considered a part of chemical flooding and in-situ combustion is a part of thermal.
GE is interested in EOR because it produces equipment that process gases and fluids. This equipment is required for injection into a well. Electricity is required at the well and this can be provided by GE gas turbines or gas engines. Mechanical drive is also available via GE products. There are also opportunities for GE products on the produced side of the oil extraction process. The extracted mixture from the well needs separation, further processing and possibly re-injection. The primary gases and fluids of interest are: natural gas (hydro carbon), water (steam), CO2, and Nitrogen. GE has researched CO2 Capture as part of the Carbon Capture and Sequestration (CCS) initiatives. Also GE has researched alternative power cycles with the aim of CO2 capture, for example GE is collaborating with Sargas on such an advanced cycle. GE Water has processing and purification products, including desalination. Low salinity water EOR is a new technology in which reverse osmosis can play a role is the size and reliability can meet offshore requirements. GE has pumps and electrical submerged pumps in its product line-up for the artificial lift operations. All this GE technology may be applied to EOR operations via customers. Therefore GE is assessing their economic viability and technical feasibility.
GE is interested in EOR because GE produces lots of equipment that process gases and fluids. EOR requires pumps for injection of stimulation fluids into a well. EOR processes also require more electricity at the wellpad. The extracted mixture from the well needs separation and cleanup. GE makes equipment in all of these areas – pumps, power production, gas separation, water cleanup. But its not as simple as dropping in standard equipment. There is a lot to be gained by examining the entire system of hardware at an EOR wellpad, and investigating even better technologies for stimulating oil production. GE Global Research has active research in this space, including alternative power production technologies for the wellpad, new pumping technologies for this challenging environment, new water cleanup technologies, and even new stimulation fluids. The outcome will be incredibly impactful, as we figure out new ways to enable the clean production of important energy fuels for a growing world.