MLchartDataset catalogue

Echo spacing

Term · Oil and gas · MLC-T-OAG-001242

The time between successive spin echoes in the CPMG pulse sequence used by an NMR logging tool, set by the interval between the 180-degree refocusing pulses and written TE. A short spacing lets the tool detect fast-decaying signals from small pores and clay-bound water, while a longer spacing increases diffusion-induced decay, which is exploited to distinguish gas and light oil from water. Typical values run from about 0.2 to 1 millisecond.

Table 1. Record
IdentifierMLC-T-OAG-001242
FieldOil and gas
SubjectFormation Evaluation
Record as JSON 
{
  "id": "MLC-T-OAG-001242",
  "term": "Echo spacing",
  "field": "Oil and gas",
  "definition": "The time between successive spin echoes in the CPMG pulse sequence used by an NMR logging tool, set by the interval between the 180-degree refocusing pulses and written TE. A short spacing lets the tool detect fast-decaying signals from small pores and clay-bound water, while a longer spacing increases diffusion-induced decay, which is exploited to distinguish gas and light oil from water. Typical values run from about 0.2 to 1 millisecond.",
  "subject": "Formation Evaluation",
  "url": "https://mlchart.com/terminology/oil-and-gas/echo-spacing/"
}

Record 1,335 of 4,469 in Oil and gas terminology (MLC-0103). Request the full dataset.