The objective of hydraulic fracturing is to increase the conductivity of an oil or natural gas zone within a reservoir to the wellbore by creating a conductive pathway to the wellbore. This increases the flow of hydrocarbons and allows a greater proportion of the in-place hydrocarbons to be extracted or produced from that zone.
Hydraulic fracturing is achieved by pumping a viscous fluid with suspended proppant (grains of quartz sand or ceramic material) through the wellbore and into the reservoir zone being stimulated. Fluids used include crude oil and other hydrocarbons, gelled hydrocarbons, slick water, emulsion (water/carbon dioxide) and pure carbon dioxide. The pumping pressure causes fractures in the surrounding reservoir rock, which accepts the fluid and proppant. The fluid is designed to subsequently “break”, or lose viscosity. This enables it to be driven out of the reservoir zone by its pressure. The proppant is left suspended in the fractures, holding them open permanently.
For more than a decade Calfrac has performed continual research, development and testing to keep improving its fracturing fluid design. We combine numerous proprietary chemistries with the base fluid. The final fluid can be friction-reduced, gelled, emulsified or foamed. Some fluids are energized by the introduction of liquid carbon dioxide or nitrogen.
In addition to the sophisticated chemistry technology that goes into the fracturing fluid, fracturing demands considerable engineering knowledge and experience so the fracturing process achieves an optimal design that maximizes well performance. Calfrac designs each fracture individually, taking account of the specific temperatures, pressures, formation permeability and reservoir fluids expected in the producing zone that we will fracture. Calfrac’s engineering personnel provide technical evaluation and job design recommendations as an integral element of the company’s fracturing service to the customer. For more on this, please click here.