Some of the surge in U.S. oil production this past spring might have been “a mirage.”

On July 31, the EIA released monthly data on U.S. oil production, which revealed a decline in U.S. output of 30,000 bpd in May, compared to a month earlier. The dip is a surprise, given the widespread assumption that U.S. shale production was continuing to grow at a blistering pace.

To be sure, a big reason for the decline in overall output was the 75,000-bpd decline in production from offshore Gulf of Mexico. But Texas production only rose by 20,000 bpd, a disappointing figure that likely came in far below what most analysts had expected.

Moreover, the monthly total of 10.442 million barrels per day (mb/d) for May is sharply lower than what EIA itself thought at the time. Here are the weekly estimates for U.S. oil production that the EIA put out back then:

April 6: 10.525 mb/d

April 13: 10.540 mb/d

April 20: 10.586 mb/d

April 27: 10.619 mb/d

May 4: 10.703 mb/d

May 11: 10.723 mb/d

May 18: 10.725 mb/d

May 25: 10.769 mb/d



The weekly estimates tend to be less accurate than the retrospective monthly numbers. That is not a new dynamic, and estimating on a weekly basis inherently involves a lot of guesswork, so this is not a knock on the EIA.

Yet the discrepancy is rather striking. Not only did the EIA estimate that production in April and May was much higher than it actually was, but the agency also thought production was rising quickly.

If the weekly estimates were to be believed at the time, production would have climbed from 10.525 mb/d in early April to 10.769 mb/d by the end of May, an increase of 244,000 bpd over a roughly eight-week period.

Not only was production lower than that, but it didn’t actually increase at all. The EIA’s more accurate monthly figures show a slight decline in output, falling from 10.472 mb/d in April to just 10.442 mb/d in May.

“Weekly data had shown a strong 324kb/d output rise from March to May. The revised data shows that this rise was a mirage: output actually fell 19kb/d over the period,” Paul Horsnell, head of commodities research at Standard Chartered, wrote in a note. Related: U.S. Oil Production Isn’t Growing As Fast As Expected

This is a rather significant development, and it has implications for more recent data releases. “It is time to deal with the statistical gorilla on the oil trading floor,” Horsnell of Standard Chartered wrote, along with analyst Emily Ashford. “We think US crude oil production has not reached the 11 million barrels per day (mb/d) shown in recent weeks in the Energy Information Administration (EIA) weekly data, and that it is significantly below 11mb/d, with growth slowing.”

That is a reasonable conclusion, given the roughly 300,000-bpd difference between the two surveys for May. The EIA has since switched its reporting for the weekly surveys by rounding off to the nearest 100,000 bpd, but data points from the last few weeks look like this:

July 6: 10.900 mb/d

July 13: 11.000 mb/d

July 20: 11.000 mb/d

July 27: 10.900 mb/d Related: Exxon’s Shocking Supply And Demand Predictions

It’s a little tricky trying to discern patterns from that data given the rounding off, but a few things jump out. First, production dipped at the end of July, a rather surprising move. Output from Alaska fell 150,000 bpd over the last two weeks, which likely explains much of the move. However, production from the Lower 48 has only increased 100,000 bpd since the week of June 22, which suggests that the Permian basin is starting to run into production constraints because of pipeline bottlenecks.

It is a little early to really get a sense of how much the Permian is slowing down. Most analysts have been assuming an overall slowdown over the next 12 months because of pipeline constraints. However, the EIA figures might suggest that the problem has already started to bite. In April, the EIA predicted in its Drilling Productivity Report that Permian production would jump by 73,000 bpd in May. But the monthly data just released finds only modest gains in Texas (+20,000 bpd) and New Mexico (+3,000 bpd).

Second, the EIA thinks output broke 11 mb/d in July, an all-time high. But judging by the overly-optimistic monthly data from April and May, perhaps the agency is also overstating July figures, which raises the possibility that production is not nearly as high as we currently think.

In the coming months, if monthly U.S. production figures continue to show output undershooting expectations, that would have global ramifications. Most analysts still are baking in strong U.S. shale growth figures into their forecasts. If that additional output fails to materialize, the oil market could end up being a lot tighter than we all expected it to be.

By Nick Cunningham of Oilprice.com

More Top Reads From Oilprice.com: