Fracking - Oil and Gas Hydraulic Fracturing Supplies
Exploiting tight gas reservoirs requires the ability to fracture wells according to production requirements. Most require multiple transverse fractures at specific locations within the horizontal well. In order to maximize productivity, the creation of multiple fractures is of critical importance. One popular method for creating fractures is the use of frac ports & sliding sleeves. Openhole packers isolate different sections of the horizontal well. A sliding sleeve is placed between each packer pair and is opened by injecting a ball inside the borehole. Typically, a compleiton string is placed inside the well. The string include frac ports and open hole packers spaced to specifications. The spacing between packaers may be up to several hundred feet. The packers are actuated by mechanical, hydraulic or chemical mechanisms. In order to activate each sleeve, a properly sized ball is pumped along with a fracturing fluid inside the well. Each ball is smaller than the opening of all of the previous sleeves, but larger than the sleeve it is intended to open. Seating of the ball exerts pressure at the end of the sliding sleeve assembly, causing it to slide and open the frac ports. Once the port is opened, the fluid is diverted into the openhole space outside of the completion assembly, casuing the formation to fracture.
At the completion of each fracturing stage, the next larger ball is injected into the well, which open the next sleeve, and so on, until all of the sleeves are opened and multiple fractures are created in the well. The main advantage of this completion technique is the speed of operation which also reduces costs.