Formation characteristics from two of its first five wells indicate that the Cretaceous Eagle Ford shale in LaSalle and McMullen counties of South Texas “is one of the highest quality shale reservoirs discovered in the US,” said Petrohawk Energy Corp., Houston.
Petrohawk raised its internally estimated ultimate recovery assumption for wells in the play to a midpoint of 5.5 bcfe/well, with a range of 4-7 bcfe/well, based on gas in place data derived from the core analysis from the two wells and performance of wells completed to date.
Petrohawk cited encouraging parameters from the two wells 30 miles apart: the Dora Martin-1H in LaSalle County and the Donnell-1H in McMullen County.
Core analysis from the two wells indicates 180-210 bcf/sq mile of free gas in place, 83-85% gas saturation, 9.4-10.7% porosity, 1,110-1,280 nanodarcies of permeability, and 4.4-4.7% total organic carbon.
Petrohawk recognizes a trend across the field from southwest to northeast of increasing condensate yield, from no condensate production from the Dora Martin-1H to a yield of 110 bbl/MMcf of gas from the Donnell-1H.
The Eagle Ford shale has been encountered in all five wells from 11,000 ft to 11,700 ft true vertical depth. Petrohawk has leased 160,000 contiguous net acres prospective for the formation in LaSalle and McMullen counties. The Texas Railroad Commission has named the area Hawkville field.
Petrohawk operated one horizontal rig in the play in the quarter ended Mar. 31 and has added a second rig.
Three wells were drilled and two were completed in the quarter. The Donnell-1H was completed on Feb. 20 at 3.6 MMcfd and 395 b/d of condensate on a 19/64-in. choke with 3,585 psi flowing casing pressure. The Brown Trust-1H was completed on Mar. 26 at a rate of 8.1 MMcfd and 200 b/d of condensate on a 24/64 in. choke with 4,210 psi flowing casing pressure.
“Production data from the four wells completed to date indicates lower initial annual decline rates, and a flatter hyperbolic decline, than those observed in other shale plays,” Petrohawk said.
The company’s first three wells, which had pilot holes, averaged 53 days from spud to rig release. The fourth had intermediate casing but no pilot hole and took 32 days. The fifth well was drilled in 22 days without intermediate pipe or a pilot hole.
Drilling and completion costs range from $4.5 million to $5.5 million/well.