A 3C-4D surface seismic and VSP program for a coalbed methane and CO₂ sequestration pilot, Red Deer, Alberta

Donald C. Lawton, Gary F. Margrave, Sarah Elizabeth Richardson, Robert R. Stewart

CREWES is embarking on a three-year program to develop and conduct a repeated seismic monitoring experiment at a site in Alberta that is proposed for coalbed methane (CBM) production, stimulated by CO₂ injection. The main objective is a proof-of-concept test for seismic-imaging technology to successfully monitor the motion of the subsurface gas plumes and assess whether time-lapse seismology can verify that the injected gases are truly sequestered. Secondary objectives are to test seismic imaging technology to monitor water withdrawal from the coal zone prior to CO₂ injection and methane production. The site is near Red Deer, Alberta, where coals of the Ardley Zone of the Lower Tertiary-Upper Cretaceous Scollard Formation are up to 8 m thick at a depth of approximately 290 m below surface. Based on numerical modelling, a surface seismic has been designed with a 400 m x 400 m patch, orthogonal source and receiver lines 40 m apart, with shot and receiver intervals of 10 m. A vertical seismic profile survey has also been designed, with 50 m source offsets to a maximum offset of 250 m.