Laird Thompson, President NWEA
Microseismic Technology - the Promise of Mapping Crustal Fluid Movement: How Reliable Is It?
Hydraulic fracing has been instrumental in establishing the commerciality of shale-based reserves. Over the past 50 years more than a million wells have been fraced – with a huge increase in recent years as the Bakken, Eagleford and Marcellus Formations have been extensively drilled for “unconventional reservoirs”. Despite all this activity, the understanding of the mechanics involved in hydraulic fracing (and subsequently delivery of fluids to the wellbore) are still poorly documented. One recent technology – microseismic monitoring during fracing – held the promise of being able to image the size and extent of the hydraulic fractures created during the fracing process. Industry experience over the past 5 years or so have shown that the simple hypothesis of a single, bi-wing extensional fracture being created has not been an appropriate model despite thousands of wells monitored for hypocenter activity during hydrofracing. An alternative microseismic technology, termed Tomographic Fracture Imaging uses a radical method of full-trace processing instead of hypocenter mapping. This fundamental difference has been shown to create images not only of hydraulic fracture mapping but also imaging the permeability structure in producing oil and gas fields – that is, not only the fractures created during a frac job, but the producing permeability structure as wells are brought on production.
Laird B. Thompson, PhD, is an industry recognized expert in borehole imaging interpretation and in the characterization of fractured reservoirs. During an almost 30 year career with Mobil Oil Corp, Laird managed the R&D program in fractured reservoirs from 1995 until Mobil was sold in 2000. A respected teacher in Mobil’s training system, Laird has continued teaching classes for AAPG since 2000. In his post-Mobil career, he has been a managing partner for UF3, Utah Faults, Fractures and Fluids, and has been teaching and consulting on fractured reservoirs, borehole imaging and microseismic analysis of permeability fields. Laird is currently involved in microseismic R&D and application for fracing effectiveness and reservoir optimization and serves as the president of the NWEA.
Northwest Energy Association