U.S. natural gas inventories likely increased by less than usual last week, narrowing the storage surplus over the five-year average and widening the deficit against the year-earlier level, according to a survey by The Wall Street Journal.

Natural gas in underground storage is seen rising by 29 billion cubic feet to 3,213 Bcf for the week ended Aug. 28, according to the average estimate of 10 analysts, brokers and traders. Estimates range from a storage build of 21 Bcf to an increase of 39 Bcf.

The expected injection is smaller than the five-year average for the week of 37 Bcf, and would lower the inventory surplus to 159 Bcf from 167 Bcf the previous week. It would leave stocks 51 Bcf below their year-earlier level, compared with a 30 Bcf deficit the week before.

The U.S. Energy Information Administration is scheduled to report natural gas inventories on Thursday at 10:30 a.m. EDT.