Introduction
In 2008, Trident Resources Corp. announced breakthrough milestones in drilling in the Corbett Creek / Ft. Assiniboine Mannville Coals. At the time, Trident lead the CBM industry in horizontal and multi-lateral drilling and completions.
From an environmental perspective, this was a signficant achievement because of the significantly reduced “footprint” - gas was produced from a single low profile wellhead which was approximately 1/17th the size of a conventional operational of similar output. Refer to Material Balance Diagnostics for another field example.
Wellbore Orientation
Using production bubbles plotted against the Canadian DLS, one can see that the horizontal wells completed perpendicular to the face cleats produced far superior than those drilled parallel to the butt cleats . According to Bustin (2015), the wells should be oriented NW-SE to N-S, and perhaps E-W.
The plot below shows the effect of anisotropy of production on a Mannville CBM horizontal well, as a function of azmuth. Highest production occurs in wells oriented perpendicular to the face cleat direction.
References:
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C. L. Jordan “Maximizing Production: CBM Well Testing & Data Management”, Pertamina CBM Visit & Workshop, 18 - 22, June 2013, QLD, AU