Muscle Replaced Guile
Problem solving approaches evolve and solutions usually get simpler and easier. For years, geologists saw petroleum shows on mudlogs and samples from low permeability intervals. But these zones would not flow in the way common saturated porous and permeable would easily produce, so those were the easier objectives. But, looking at the in-place potential reserves was always floating out there in imaginations, and intrigued those with the time and background to think about them.
Modern computer processing has speeded up many tasks, allowing us to do things that were always proposed to be improvements, such as prestack reflection surface seismic processing and neural network analysis of often-disparate and irregular data types. Over my career, the amazing reduction of electronic data storage costs has flipped the approaches to information storage. Well log data files from several types of downhole surveys could be put on a single eight inch spool of tape in the early 1980s, while the dipmeter log surveys took a tape reel over a foot across. Since the disk storage space back at the office was precious, the underlying microlog surveys for the diplogs were often deleted, once the dips (“tadpoles”) were calculated, and the original tapes uses as scratch tapes. Modern software techniques can now produce amazingly improved dip results from these field log data, but many tapes are long gone. So the opportunity to use more muscle here is gone.
The past two decades have shown that the combined technologies of hydraulic fracturing and horizontal drilling can be used to recover in-place petroleum from low-permeability rocks. As time has progressed, we have not just used a bigger hammer, but have used more hammers on our subsurface nails in our efforts to create more extensive and homogeneous damage halos around boreholes to allow the tight country rock to drain into the boreholes. However, the reported recoveries of in-place reserves are generally less than five percent. And we know from the 1967 Gasbuggy experiment that a bigger hammer does not always give the desired results.
It’s time for us to think harder on this recovery problem, now that muscle has been applied about as far as possible. Get to it.
So, what is this page’s title about? I heard the phrase on an afternoon’s play of the Engines of Our Ingenuity show on KUHF. The topic of the day was nomograms, which used to be widely used for log analysis calculations to visually determine values from often-nonlinear relationships or observed values. The author, John Lienhard, was reflecting on how we now have machines to do involved calculations that we used to work around by graphical techniques. Now you may go look for your “tornado charts”. n
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