A Fracking rig

Half of the 41 fracking companies operating in the U.S. will be dead or sold by year-end because of slashed spending by oil companies, an executive with Weatherford International Plc said.

There could be about 20 companies left that provide hydraulic fracturing services, Rob Fulks, pressure pumping marketing director at Weatherford, said in an interview Wednesday at the IHS CERAWeek conference in Houston. Demand for fracking, a production method that along with horizontal drilling spurred a boom in U.S. oil and natural gas output, has declined as customers leave wells uncompleted because of low prices.

There were 61 fracking service providers in the U.S., the world’s largest market, at the start of last year. Consolidation among bigger players began with Halliburton Co. announcing plans to buy Baker Hughes Inc. in November for $34.6 billion and C&J Energy Services Ltd. buying the pressure-pumping business of Nabors Industries Ltd.