Thermal capture

{
  "id": "MLC-T-OAG-003803",
  "term": "Thermal capture",
  "field": "Oil and gas",
  "definition": "A nuclear interaction where a low-energy (thermal) neutron is absorbed by an atomic nucleus, which then becomes excited and emits a gamma ray. Pulsed neutron logging tools use this principle to measure the formation's thermal neutron capture cross-section (Sigma), a property that indicates the probability of this reaction occurring. Because chlorine has a very high capture cross-section compared to hydrogen and carbon, Sigma logs are effective for distinguishing between saline water and hydrocarbons in cased-hole wells where resistivity measurements are not possible.",
  "subject": "Formation Evaluation",
  "url": "https://mlchart.com/terminology/oil-and-gas/thermal-capture/"
}