Fracturing in petroleum engineering - Research Paper Example

Therefore, this research paper addresses hydraulic fracturing with respect to fracturing process, mechanics of fracturing, history of fracturing, types of fracturing fluids and additives and the types of fracturing processes. Hydraulic Fracturing Hydraulic fracturing involves the use of fluid, which is pumped at a determined high pressure into a given section of the wellbore, to enhance oil production. The high pressure liquid finds its way into the rock formation containing oil and creates fractures from the wellbore, which extends into the oil containing rock formation (Yew 1).

The established fractures provide flow paths of oil into the wellbore, which is then pumped out of the oil well. Figure 1 shows the hydraulic fracturing process. As shown in figure 1, the pressured fluid pumped through the well bore leads to fracture propagation in the fracturing stages of the process. Figure 1: Hydraulic fracturing process (EPA) History and Examples of Fracturing The use of fracturing in petroleum engineering to stimulate oil production started in the 1860s, long after oil production was invented.

Over time, considerable advancement has been experienced in the field of hydraulic fracturing particularly with respect to the development of hydraulic fluid combinations for maximum efficiency (EPA 1). Other developments include the development of enhanced equipments for injecting fluid and monitoring relevant data especially fluid pressure, fracture depth and fracture width (Yew 6). Hydraulic fracturing has been widely applied in the petroleum industry. For example, statistics show that fracturing is usually conducted to about 90 percent of oil wells in the United States to stimulate oil production (Earthworks).

Mechanics and the Process of Hydraulic Fracturing Hydraulic fracturing can be done on oil wells that have been drilled horizontally, vertically or directionally (slanting) (EPA 1). Fluids used in hydraulic fracturing are comprised of water (or methanol, oil or a combination of methanol and water in strategic proportions) and chemical additives. Water-based hydraulic fracturing fluids are the most common of the four types of hydraulic fluids. Water content in hydraulic fracturing fluids is highly dependent on the rock formation and the site of fracturing, and it can be up to 99 percent implying that additives can be as little as 1 percent of the fluid content (EPA 1).

The quantity of fluid for hydraulic fracturing also depends with site (depth of oil well) and rock formation. Generally, water quantity may vary between 50,000 gallons (189 m3) to about 350,000 gallons (1325 m3) (EPA 1). Silica sand or other small particles (technically known as proppant or propping agents) are added into the hydraulic fracturing fluid, which serves to maintain the open position of the established fractures (propping/supporting). The principle behind hydraulic fracturing is that the hydrostatic pressure of the injected fracturing fluid should exceed the parting pressure of the target rock formation thereby inducing a network of fractures through the rock (Spellman 11).

The fractures arising from the fracturing process are technically referred to as hydraulic induced fractures. Since fracturing operation is usually conducted at enormous depths (oil exploration occurs at large depths), hydraulic