For the second straight year, most crude produced in the Lower 48 in 2016 was light oil with API gravity of 40.1 or higher, the U.S. Energy Information Administration (EIA) said in a report April 19.

The trend of rapidly rising domestic crude production since 2010 derives from the success of E&Ps extracting oil from tight formations, which contain light oil, the EIA said. In 2016, 51% of the 8.4 million barrels per day (MMbbl/d) produced was light oil.

The major producing state of North Dakota produced less light oil in 2016—about 900 Mbbl/d compared to 2015’s 1.5 MMbbl/d, while California produced no light oil in either year, with 2016 seeing a decline in crude output of API gravity below 30— just above 400 Mbbl/d in 2016 vs. about 450 Mbbl/d in 2015.

Meanwhile, Texas produced more light oil in 2016—just above 1.6 MMbbl/d—compared with 2015’s average of just-below 1.6 MMbbl/d. Texas also produced less oil with an API grade higher than 50 last year—just above 400 Mbbl/d compared with 600 Mbbl/d of a 50, or heavier, API  grade in 2015.

Texas’ oil production is robust. Based on EIA data on API gravity of crude, Texas produced more oil in all categories of API grade than North Dakota and California.

Data from the agency’s March 31 “Monthly Crude Oil and Natural Gas Production Report” that was used to base the above graph showed that Texas outranked 30 states and two federal offshore areas in production for January 2017. Texas produced about 3.19 MMbbl/d in January 2017, which was 4.9% lower than January 2016’s roughly 3.36 MMbbl/d.

According to economist Karr Ingham in an April 19 report from the Texas Alliance of Energy Producers, “2017 is going to be a year of recovery and expansion in the Texas statewide oil and gas [E&P] economy.”

In first-quarter 2017, producers recovered an estimated 291.4 MMbbl of crude in Texas, the report said.

Reuters reported April 18 that, specifically in the Permian Basin in West Texas and New Mexico, production in May could rise to 2.36 MMbbl/d—an increase of nearly 76 Mbbl/d based on EIA data. May production in Texas’ Eagle Ford Shale could rise to 1.22 MMbbl/d, an increase of 39 Mbbl/d.

Related: Crude Oil Prices Slide As US Adds Output

Erin Pedigo can be reached at epedigo@hartenergy.com.