For the last several years, there have been numerous technical workshops on injection-induced seismicity which, looking back, serve as snapshots documenting the rapid evolution in our understanding of this important topic. With time, the tone of these workshops has changed in step with advancement by industry, regulators and academics managing this critical issue. Early discussions focused on education and awareness of the causes and cases of induced seismicity. This was followed by reactive implementation of regulated traffic light systems, and now development of more proactive operational strategies to mitigate induced seismicity.
A magnitude-based, traffic light protocol is the most common mitigation approach to injection-induced seismicity, adopted by both regulators and operators throughout North America. Despite challenges associated with a protocol based on an estimate of seismic source strength, magnitude-based protocols still prevail over alternatives such as using measured ground motions.
“Induced seismicity” refers to a seismic event that is caused by pore pressure and stress change associated with human activity (Boroumand and Maghsoudi, 2016). The maximum magnitude of induced earthquakes is smaller than what is seen with natural earthquakes (Metz et al., 2017); they tend to occur in swarms (Metz et al., 2017); and occur at shallower depths than natural earthquakes (Gomberg and Wolf, 1999; McNamara et al., 2015; Metz et al., 2017), which may explain why they have been reported to be felt at surface (Boroumand and Maghsoudi, 2016) though they are small in magnitude.
In the Gulf of Mexico (GoM), with complex salt geometry, it is not unusual to see coherent noise in subsalt imaging. Such noise is detrimental to subsalt exploration and appraisal as they often lead to incorrect interpretations.
We focus on extracting new value to previously acquired orthogonal WAZ surveys in the Mississippi Canyon area where some of the largest and still active deep water discoveries reside. Some analyses estimate that many large subsalt/presalt fields can still be discovered.
In Mississippi Canyon a unique characteristic of salt geometries are their stacking hourglass shapes – autochthonous Louann salt forms the lower part, allochthonous Mesozoic salt forms the middle part, and Cenozoic salt canopy forms the shallow part.
In September 1985, the first edition of the RECORDER was launched. Having evolved from our humble CSEG member newsletter, the RECORDER has grown into a well-received and respected publication within both the energy and geophysics fields. Like the industry around us, the RECODER continues to evolve to meet the needs of our readers.