Explainers
How the subsurface works, one question at a time
Short pages on the mechanisms and methods behind legacy well, produced water disposal, and induced seismicity matters, each explaining one thing without dated statistics. More are added as the questions come in.
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01
A glossary of legacy well terms
The words that decide who pays, which agency has jurisdiction, and what a record can be asked to prove: well status, construction and failure, disposal and injection, seismicity, money and liability, and records, defined as the article series and the practice use them.
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02
How to read a legacy well file
What a state well file contains, what the permit, completion report, logs, production history, plugging report, and scout tickets can and can't establish, and where the record usually runs out.
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03
How pressure moves out from a disposal well
Why the pressure from a saltwater disposal well doesn't stop at the permit radius, what decides how far it reaches, and what that means for the old wellbores in its path. The mechanism behind area of review analysis, written for counsel, landowners, and regulators.
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04
How an induced seismicity assessment is built
What it means for an earthquake to be induced, what goes into deciding whether seismicity near a site is consistent with injection (catalogs, injection records, faults and slip potential, regulator protocols, surface deformation), and what the finding does and doesn't say.
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05
Testing whether production changed because of a neighbor
How a claim that a well's production or water cut changed because of nearby injection or completion is tested statistically: interrupted time series with controls, autocorrelation-robust errors, changepoint detection, placebo dates, and the moving-block bootstrap, and what the result can and can't say.
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A question that isn't here yet
Start with the question
Send it, with a sentence on what records exist. A short call follows.