Thief zone

{
  "id": "MLC-T-OAG-003814",
  "term": "Thief zone",
  "field": "Oil and gas",
  "definition": "A formation interval, such as a highly permeable sand, a vugular carbonate, or a natural fracture network, that takes drilling fluid from the wellbore and causes loss of circulation. Fluid enters it whenever the mud pressure in the hole exceeds the pressure in the zone, and fractures induced by excess pressure can create a thief zone where none existed. In waterflooding the same term names a layer that takes most of the injected water.",
  "subject": "Drilling",
  "url": "https://mlchart.com/terminology/oil-and-gas/thief-zone/"
}