DNA Sequencing For Shale Wells

DNA sequencing technology can help maximize production in horizontal shale wells by directing operators where to place the wells, and how they should be completed.

“Think of the DNA as a tracking device, It is a high resolution data source that provides 4D analysis across the production life cycle, which doesn’t introduce environmental risk or require downhole tools.”

microbial DNA sequencing is about as accurate as chemical tracers
For the application of production profiling, same-well comparisons have shown that microbial DNA sequencing is about as accurate as chemical tracers, and it provides usable data over the life of the well, not just the life of the tracer. Graphic courtesy of Biota.

During a drilling operation, as many as 600 samples may be taken from a single well. These samples come from drilling mud and cuttings and provide baseline data needed to characterize the well as production begins and comingles all of the microbial DNA.

More samples are taken during completion operations and then from produced oil and water during production. To screen for contamination, Biota samples several sources of DNA, including the humans working on the job and any dirt at the drillsite that may be swept into the well during operations.

All this information is compiled and sifted through by the data scientists and its machine learning software to find the most simportant correlations.

As it continues to build a track record and demonstrate its value proposition.

But the company notes that it was founded on the idea that the new and
dramatically lower price point meant shale producers could now afford to
use DNA sequencing as a diagnostic technology in each and every well—an
aspect that the company hopes will distinguish it from the established technologies it is competing against.

Production logs are generally viewed as expensive and they require wells to
be shut in for a period of time until the tool run is completed. Biota’s sampling process is done at the surface, from a shale shaker or a flowline for instance, and requires no shut-ins or anything to be sent downhole.

“Tracers and microseismic are also great tools, But you can’t get that 4D snapshot along the life cycle of the well—you get an initial point in time and that’s their real limitation.”

Biota is also putting its technology next to downhole fiber-optic systems
which have gained wide acceptance in the industry for their ability to
deliver high-resolution data. Like DNA sequencing, fiber-optic systems provide data for months after installation, if the fiber remains intact, but their biggest downside is cost. At around USD 1 million per installation, fiber-optic systems are generally used only on pilot projects and science wells.

Perhaps the most similar technology to DNA sequencing in terms of data output is geochemistry testing. DNA sequencing and geochemistry tests can be run at any point in time to analyze the makeup of a well’s production stream and depend on the presence of organic materials to generate usable insights.

Biota says its DNA data line up with geochemistry tests, per independent
studies. But the company points out that DNA sequencing provides 1,000 times more data than a geochemistry test, which allows it to detect much smaller variations in production behavior.

The company has also explored DNA sequencing applications for conventional wells and offshore production facilities. In the short term, Biota has goals to integrate DNA data with other subsurface data sets that companies routinely use. Farther down the road, it hopes to develop new ways to analyze the DNA data in real time. Current lead time from field to laboratory results is about 2–3 weeks.

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