Abstract

In late 2009, the EOG Resources Jake 2-01H horizontal well (Sec. 1, T11N, R63W, Weld County, CO) re-opened the Niobrara oil play in the DJ basin. The play for EOG was built on comprehensive geologic scrutiny across the entire DJ basin of Colorado and Wyoming. Niobrara tests in the original Hereford field, four miles east of the Jake discovery, had bypassed Niobrara pay. This data, along with a 1991-vintage horizontal well with a vertical core through the Niobrara B Chalk in the original Hereford field, set up the prospect around the Jake discovery. A proprietary 40 square-mile 3-D seismic survey acquired and processed between May and July 2009 provided data for well-location planning. Determination of current-day maximum horizontal stress of N55°E in the Lamotta 5-01M monitoring well led to the drilling of the Jake 2-01H, although the Jake well was not the original planned location for the first horizontal test in the prospect area. Since the Jake discovery, EOG has drilled 71 Niobrara horizontal wells in Hereford field, and industry has drilled more than 4400 horizontal wells in the entire DJ basin Niobrara play.