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Methods of Enhanced Oil Recovery Essay example

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Introduction With almost 200 billion barrels of technically recoverable oil reserves located in the United States alone, it is not surprising why so many companies are adopting enhanced oil recovery techniques in everyday operations (“Total energy”, 2012). Oil production can be broken down into three main components: primary, secondary, and tertiary recovery. Primary recovery is when the well is first drilled and the natural pore pressure of the rock squeezes hydrocarbons out of the pore space. During this time the hydrocarbons are put under immense pressure and the majority of the liquids and gases will flow to the top. Secondary recovery is when water and gas injection are used to transfer the oil from the reservoir to the surface.…show more content…
Cyclic Steam Stimulation An example of thermal recovery is cyclic steam stimulation which is a method of increasing oil production by going through multiple steam cycles. First a steam generator heats water to produce steam so that the injection wells can heat the surrounding formation. Then the well is shut in and the heat is given time to diffuse into the oil, which reduces the viscosity of oil. Soon afterwards, the well returns to production and the initial oil rate is higher due to the increase in reservoir pressure. Once the heat has dissipated far into the formation, the oil saturation may drop because the porosity no longer has an external force holding the space between the grains open. After the initial cycle has been completed the cycle can be three to four times before production gains become insignificant. Steam Assisted Gravity Drainage Steam assisted gravity drainage (SAGD) is also a type of thermal recovery which injects steam into horizontal wells for heavy oil reservoir production and tar sand production. (Steam assisted, 2013). SAGD begins by drilling two parallel horizontal wells about four to six meters apart. The upper well will have steam injected into it while the bottom well is used to collect the heavy oils, such as Bitumen. As the steam spreads throughout the formation in all directions, any gases, such as CH4, CO2 and H2S, will ascend to the top of the
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