Advanced techniques to excavate unconventional petroleum resources
The drilling and excavation of petroleum, oil and gas where such reservoirs are located has been an essential part of energy production over generations. The price of these resources due to resulting supply and demand forces have the potential to impact financial markets on a daily basis, thus energy and utilities is a major influencer on the economy. However, like any other natural resource, conventional sources of oil are declining which has led to increased interest in alternative (or unconventional) oil and gas. But how can this be obtained and is it profitable in the long run? This blog will discuss some advanced methods which can be game-changers in the process of unconventional oil exploration and extraction.
Surface Mining
Oil recovery in the oil sands uses two main methods: mining or in situ, depending on how deep the oil sands deposits are. Surface mining is used when oil sands deposits lie within 70 meters (200 feet) of the earth’s surface. Twenty per cent of oil sands reserves are close enough to the surface to be mined. Large shovels scoop oil sand into haul trucks that transport it to crushers and pressure vessels where large clumps are broken down. This oil sand is then mixed with hot water and pumped by pipeline to a plant called an upgrader, where the bitumen (oil) is separated from the other components such as sand, clay and water.
In Situ Recovery
Deeper bitumen must be recovered using in situ technology. “In situ” means “in place,” because bitumen is separated from the sand below ground, right in the deposit itself. This is accomplished by heating the bitumen so it becomes fluid enough that it can be pumped to the surface. There are several ways to heat bitumen below ground. Both of the commonly used methods – SAGD and CSS – use large volumes of water and burn natural gas to create steam that is injected into the oil sands deposit. New research is leading to technologies that reduce or eliminate the need for water and natural gas.
Steam-Assisted Gravity Drainage
Currently, most in situ operations use steam-assisted gravity drainage (SAGD), which uses well pairs (two wells, an injection well and a production well, drilled one above the other) to recover bitumen. The injection well is drilled vertically into the deposit, then turned 90 degrees and drilled horizontally. A second well, known as the production well, is drilled deeper than the first, paralleling the horizontal portion of the first well. Steam is injected into the deposit through the upper well. Heated bitumen begins to move by gravity down toward the second well. Pumps in the second well draw the bitumen into the well and up to the surface. Multiple wells (sometimes more than 20) can be drilled from a single surface location, further reducing surface disturbance.
Conclusion
Obtaining unconventional petroleum products can be a cumbersome process at times, however it is a necessary part of exploring alternative resources. Since unconventional petroleum is more difficult to bring to the surface, it requires precision and patience to extract the raw product so as not to damage the oil source or cause any other environmental disturbance. As a result, oil and gas giants are investing majorly into advanced equipment and training the necessary personnel in this regard; after all, the machine is only as good as the individual who wields it!