Annulus

{
  "id": "MLC-T-OAG-000136",
  "term": "Annulus",
  "field": "Oil and gas",
  "definition": "The space between two concentric objects, such as between a pipe and the wellbore wall or between two strings of pipe. In drilling, the most common reference is to the space between the drill string and the casing or open hole, through which drilling fluid returns to the surface. The fluid velocity in the annulus is a key parameter for effective hole cleaning.",
  "subject": "Drilling",
  "url": "https://mlchart.com/terminology/oil-and-gas/annulus/"
}