API Gamma Ray Unit
Definition - What does API Gamma Ray Unit mean?
This is a measurement unit that is used to calculate the radioactivity of the natural gamma ray logs. Since rocks are naturally radioactive, they have NORM (naturally occurring radioactive materials) such as radium, potassium, and uranium in them. All rocks have different gamma ray concentration and this intensity is measured by API Gamma Ray Unit. When an oil well is drilled, readings from the rocks are taken to inspect their gamma ray logs down hole. These readings can get slightly affected by the source of radioactivity and the drilling region.
Petropedia explains API Gamma Ray Unit
Rocks usually contain naturally occurring radioactive materials (NORM). These materials can be present in small or large quantities within the rocks. API Gamma Ray Unit is a radioactivity unit that is used to determine the intensity of radioactive materials such as uranium, potassium, radium, etc. These are commonly found in the rock formations and can be found in large concentrations underneath the earth’s surface. When an oil well is drilled and well-analysis is conducted using LWD tools (logging while drilling), the readings from these rocks can be used to determine how safe the well is.