The term or results when drilling for oil ';OIL BASED MUD'; what does that mean?

The ';mud'; used while drilling keeps the hole under pressure so it doesn't blow out. In the early days, they blew out often because Mud wasn't used then. The Mud is heavier than salt water, so it exerts more pressure at the bottom of the hole, and it suspends the cuttings better than water, for removal.





When drilling several thousand feet deep, several different types of rock are encountered: shale, sandstone, limestone, etc.





Some of these rock type swell when flushed with water, and causes problems with the drilling. So oil or deisel is substituted in place of water to mix the mud in.The term or results when drilling for oil ';OIL BASED MUD'; what does that mean?
I never drilled for crude oil, but I was an environmental driller for some years. I never heard that term. The term ';mud'; was used for drilling fluid or grout. When we mixed mud, we were mixing a combination of sodium bentonite and water, or portland cement and water. There may be an oil based drilling fluid used in oil, gas or mineral exploratory drilling. Being on the environmrntal side of things, we only used water based fluids. Hope that helps!The term or results when drilling for oil ';OIL BASED MUD'; what does that mean?
ordinary drilling mud is water based. some special drilling applications require oil-based which uses diesel fuel etc.
There are various types of Drilling Fluids (MUD). The most common are: Water Based Mud (WBM), Sythetic Based Mud (SBM), and Oil Based Mud (OBM). WBM's base fluid is Water, OBM's base fluid is Diesel, SBM's base fluid is synthetic fluid rather than an oil.


Some people refer to OMB %26amp; SBM as ';Oil Based Mud';. Technically this is incorrect.