MLchartDataset catalogue

Diffusion relaxation

Term · Oil and gas · MLC-T-OAG-001083

The shortening of the transverse relaxation time T2 of a fluid caused by molecules diffusing through a gradient in the magnetic field during the CPMG echo train. The added decay rate equals the diffusion coefficient times the square of the product of the gyromagnetic ratio, the gradient and the echo spacing, divided by 12, so it grows with all three. It is largest for gas and light oil, whose diffusion coefficients are high, which makes it the basis of diffusion-based fluid typing.

Table 1. Record
IdentifierMLC-T-OAG-001083
FieldOil and gas
SubjectFormation Evaluation
Record as JSON 
{
  "id": "MLC-T-OAG-001083",
  "term": "Diffusion relaxation",
  "field": "Oil and gas",
  "definition": "The shortening of the transverse relaxation time T2 of a fluid caused by molecules diffusing through a gradient in the magnetic field during the CPMG echo train. The added decay rate equals the diffusion coefficient times the square of the product of the gyromagnetic ratio, the gradient and the echo spacing, divided by 12, so it grows with all three. It is largest for gas and light oil, whose diffusion coefficients are high, which makes it the basis of diffusion-based fluid typing.",
  "subject": "Formation Evaluation",
  "url": "https://mlchart.com/terminology/oil-and-gas/diffusion-relaxation/"
}

Record 1,157 of 4,469 in Oil and gas terminology (MLC-0103). Request the full dataset.