Based in Mahone Bay, nova scotia, agile libre is an independent publisher of technical books about the subsurface.  

Where did the data come from?

We calibrate geophysical models with physical measurements of the earth’s properties. It is therefore important that we understand how the data are ac­quired and processed before landing on our desks for interpretation. Conversely, understanding how the data will be interpreted helps the acquisition and pro­cessing teams produce the best product.

To improve the interpretability of geophysical data, whether it’s surface seis­mic, VSPs, well logs, gravity, magnetic, or some new technology, we should know the theory, help plan acquisition and processing, get out into the field as often as practical, quality check data processing, and help spread knowledge between teams.

Know the theory so that you can push the limits of interpretation without over-interpreting the data or falling into pitfalls. This is especially important when evaluating or applying new technologies. Ask questions, consult experts, and improve your understanding as the technology progresses.

Help plan acquisition and processing so that it is fit for purpose. Survey de­signs and processing parameters depend on a number of factors including regional versus focused targets, depth of investigation, structural or strati­graphic interpretation, and required resolution.

Get into the field as often as practical to understand both the general acquisi­tion process and the specific conditions under which the data are being ac­quired. Each survey is slightly different and the crew rotates regularly, so seeing the field conditions and talking to people often helps you identify when things are going wrong. On a specific seismic survey, the hole in the survey may be avoiding a swamp, the geophones may be poorly planted due to freezing con­ditions, and the line deviation in a marine survey may be due to icebergs or existing infrastructure.

Quality check data processing so that you understand how the final measure­ments were derived from the field data. More importantly, add input where needed (for example, ensuring that velocities are geologically reasonable), build a rapport with the processing team, and ensure that the data are fit for purpose.

Spread knowledge between teams so that everyone is aligned in acquiring good geotechnical measurements. This might be needed in unexpected places. Recently, I visited a frontier exploration rig that had failed to find hydrocarbons at the target. Morale was low and the crew was mentally ready to pack it in. They didn’t see much use in spending time recording final logs or a VSP. Most had no geoscience background and didn’t understand why we would drill in that loca­tion in the first place. I heard things like ‘what on earth are we doing out here?’ So, to give the project context, I gave an impromptu presentation on frontier exploration covering the identification of a basin, understanding the petroleum system, putting the geotechnical story together, and, most importantly, the value of acquiring data. I told them that if we rush the data acquisition we may walk away with nothing, but if we ensure that we at least take away good data then we have something to build the story upon and are more likely to be successful in the future. By hearing how we used the data, the crew had more ownership of the process and became part of the exploration team.

Trust your observation skills

Time and motion

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