HOUSTON (Reuters) – Roughly 20 percent of the hydraulic fracturing fleets that were active in mid-2018 have now been idled or are being idled, as lower oil prices prompt producers to tighten their budgets, Liberty Oilfield Services estimated on Tuesday.

The company in its fourth quarter earnings release said a number of customers made last-minute decisions to defer well completions due to budgeting and cash flow management decisions, in part due to the drop in oil prices at the end of last year.