The Jilliby-1A (JB 1A) is the first of two production wells planned for Wyong with both being fracture stimulated, completed and - when dewatered - be put through a production flow test program.

Sydney Gas is aiming for a target depth of around 480 metres for JB 1A and 610 metres for JB 2A. The former is being aimed at the Great Northern coal seam, while the latter is being aimed at the Great Northern as well as the Borehole (558 metres) and the Montrose/Wave Hill seams (541 metres).

In a press release Sydney Gas stated, "The JB 1A and JB 2A production wells are being drilled to gather as much production data as possible. This will not only assist Sydney Gas to test the geological model and ultimately delineate the high production fairway being developed for the Wyong area, but will also determine the gas potential of three major coal seams for the future development of the whole Wyong Gas Project."