Equivalent circulating density

{
  "id": "MLC-T-OAG-001318",
  "term": "Equivalent circulating density",
  "field": "Oil and gas",
  "definition": "The effective density exerted by a drilling fluid column when it is circulating, accounting for the frictional pressure losses in the annulus. This density is higher than the static mud density and is calculated by adding the annular pressure loss to the hydrostatic pressure, then dividing by the true vertical depth. Maintaining ECD within a narrow window prevents wellbore instability and lost circulation.",
  "subject": "Drilling Fluids",
  "url": "https://mlchart.com/terminology/oil-and-gas/equivalent-circulating-density/"
}