WorldWide Drilling Resource

Adapted Aerospace Technology Helps Hydraulic Fracturing Process Adapted from Information by Ceramic Technologies Corp. During hydraulic fracturing, one of the biggest and most costly setbacks are screen outs. A self-destructing ball and large bore plug system promises to resolve screen outs without operator intervention. Dave Hornak is a gas and oil industry consultant and previous manager of reservoir stimulation for a firm which completed over 180 wells last year. According to him, the company had several crews working 24/7 installing an average of 30 plugs in each of the 180 wells. Given the volume, screen outs were “something to avoid, if at all possible.” Screen outs occur when proppant in fracturing fluid, such as sand or other solids, restricts flow within the wellbore or the perforations (perfs). The restriction causes a rapid rise in pump pressure. To resolve the screen out, the crew would have to rig down the wellhead and use large coiled tubing under pressure, to clear any obstruction, which could take a day or more. Dave began researching ways to improve the process and decided to test DetBall, a self-destructing ball for large bore plugs. DetBall is patented by Ceramic Technologies Corp., a Houston-based company providing advanced material solutions to a variety of industries, including gas and oil. The technology was developed with the assistance of Ensign-Bickford Aerospace & Defense Company, an aerospace defense contractor responsible for explosive applications such as those used for emergency ejections of pilots on jet planes. The self-destructing hollow ball (made of a magnesium-aluminum alloy with a small amount of internal explosive), is designed to detonate at a preset time (usually 3-4 hours) with precisely controlled, minimal force sufficient to break the ball apart and not damage the plug or surrounding casing. The remaining fragments are water soluble and will dissolve in 2-3 days. For safety and effectiveness in preventing screen out, the ball is designed to self-destruct after being exposed to a sustained pressure greater than 1500 psi (pounds per square inch). A timer counts down until the ball self-destructs. As an added safety feature, if the ball is ever brought to the surface after activation, the lack of pressure will ensure it does not detonate. Hornak and his crew tested the DetBalls in three wells, and no screen out condition occurred. He also tested the balls under simulated high-pressure conditions to ensure they performed as expected. “When we tested the balls, we put them in place, increased the pressure, and then waited for them to pop,” said Dave. “What is unique about the DetBall is the fact that you can time the detonation of the ball. All you have to do is wait a few hours for the ball to detonate. With the ball gone, the plug is open and you . . . can pump into open perfs, flush the wellbore, or put down another ball and plug, and go about your business.” 14 NOVEMBER 2020 WorldWide Drilling Resource ® A split view of the DetBall. G&O