Integration of New Technologies to Map Structural Features and Improve Stimulation Treatments in Shale Gas Plays: Coupling Surface Seismic, Microseismic Mapping, and Wireline Logs in the Fayetteville Shale Formation
Donald N. Burch1 and Joël H. Le Calvez2
1Aspect Abundant Shale, LP, Denver, CO
2Schlumberger, Houston, TX
Considerable volumes of gas are currently being produced from unconventional shale reservoirs such as the Barnett and Fayetteville Shales in the US. These plays are partly technology driven and partly economics-driven. Modern well log evaluation techniques and completion methods are required to yield economic wells. Among many, two principal geologic factors govern gas production from these formations: ultra-low matrix porosity and permeability as well as fracture-induced permeability. These shales are extremely low porosity reservoirs that must be effectively hydraulically fracture stimulated. Additionally, analysis of these shales illustrates how structural geology (by the means of basement structure influence, differential shortening effects, etc.) as well as sequence stratigraphy and depositional history yield stress field variations both laterally and with depth.
To avoid making too many assumptions about the fracture stimulation geometry, monitoring of the induced microseismic activity may be employed. Advanced processing algorithms and transmission techniques allow an on-site geophysicist to process large amount of data and to deliver microseismic hypocentral locations in a matter of seconds. Integration of induced microseismic event locations in 3D, surface 3D seismic and sonic logs can add additional valuable information to help understand the nature of the reservoir and the hydraulic treatment behavior.
Using an example from the Fayetteville Shale play, this paper highlights the integration of real-time microseismic monitoring of hydraulic fracture treatments with surface seismic data (i) to detect potential sub-seismic scale structural geo-hazards, verify interpreted fault geometries and (ii) to allow on-the-fly changes in fracture stimulation design to maximize the reservoir volume effectively contacted by the stimulation treatment.
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery