Oklahoma City-based Continental Resources Inc., the Bakken’s largest leaseholder, said Monday it has raised its reserves estimates for parts of the Bakken Three Forks area by 57% to 903 billion bbl following completion of an initial test well.

One of the nation’s leading petroleum liquids producers, Continental said it successfully completed its first horizontal well (Charlotte 3-22H) testing the third bench of the Three Forks zone in the Bakken in parts of both North Dakota and Montana.

The test well flowed 953 boe/d at 1,700 psi in its initial one-day test period, Continental said. Located in McKenzie County, ND, the well was drilled to a depth of 21,324 feet, including 9,701 feet of lateral section. It was completed with Continental’s standard 30-stage fracture stimulation design, the company said.

According to company reports, Continental is the leading acreage holder in the Bakken with 984,000 net acres. Rounding out the top five are Hess Corp. (900,000), Whiting Petroleum (714,567), ConocoPhillips (626,000) and EOG Resources (600,000).

Continental considers itself a pioneer in discovery and development of the Three Forks reservoir in the Bakken, claiming to be the first to “demonstrate increased reserves” there in 2008 and the first to establish commercial production in what is designated as TF2 in 2011. Now it has verified production at a separate location (TF3), said a Continental spokesperson, calling it “a significant milestone.”

“The well has been producing for 15 days, and its performance compares favorably with other first bench [TF1] and second bench [TF2] producing Three Forks wells,” said Continental CEO Harold Hamm. “This could be a real game-changer.”

Hamm said the test well is the first in a proposed 14-well program that Continental plans to complete by the end of next year to test productivity of the second, third and fourth benches of the Three Forks over a broad area of the play.

“The 1,280-acre Charlotte unit is the first in the Bakken field to have wells producing from three separate horizons: the Middle Bakken, TF2 and TF3 zones,” said the spokesperson.

Two years ago, Continental said it estimated the Bakken would eventually yield 24 billion boe. That estimate included 20 billion bbl of oil and 4 billion boe of natural gas, assuming 577 billion bbl of original oil in place.

Noting that the results so far are encouraging, Continental’s Jack Stark, senior vice president for exploration, said the company’s goal for 2013 is to assess the “productivity and reserve potential of the lower benches of Three Forks. There may be upside to our estimate of 24 billion boe of recoverable reserves for the Bakken.”