U.S. natural gas inventories likely posted their smallest weekly increase of the current injection season as hot August weather supported electricity-sector demand, according to a Wall Street Journal survey of analysts.

Natural gas in underground storage facilities is expected to have risen by 18 billion cubic feet to 3,171 Bcf, according to the average estimate of 12 analysts, brokers and traders. Estimates range from an injection of 7 Bcf to an injection of 40 Bcf.

The expected increase is smaller than the 29 Bcf average for the week during the 2021-2025 period, and would trim the surplus over the average to 187 Bcf from 198 Bcf the week before.

The U.S. Energy Information Administration is scheduled to report the storage data on Thursday at 10:30 a.m. EDT.