Micelles - A molecular aggregate that constitutes a colloidal particle. 



Motte - An isolated group of trees or shrubs of variable areal extent, usually 

 occurring in grassy savannahs or prairies. 



Mouse hole - A hole drilled under the derrick floor and temporarily cased in 

 which a length of drill pipe is temporarily suspended for later 

 connection to the drill string. 



Mud - The liquid that is circulated through the wellbore during rotary 

 drilling and workover operations. 



Pad - That portion of a well-drilling site that supports the drilling derrick 

 and associated facilities. 



Perched - Groundwater is said to be perched if it is separated from an under- 

 lying body of groundwater by unsaturated rock. 



Perforation - The process of piercing the casing wall and cement in order that 

 materials may be introduced into the annulus. 



Petroleum fraction - One of several hydrocarbon portions separable by fractiona- 

 tion or other separation processes. 



Phytoplankton - The passively floating or weakly swimming, usually minute, 

 plant life of a body of water. 



Pig - A Scraping tool forced through a flowline or pipeline to clean out wax 

 or other deposits. 



Pipeline spread - A spread for pipeline construction is the line of men and 

 equipment involved in building a pipeline. The spread may extend 

 several miles and move up to two miles per day along the route. 



Polish - To treat and filter out deleterious substances from produced water 

 before disposal. 



Production rig - A small derrick and associated equipment usually mounted on a 

 truck that can be easily moved over a producing well for routine 

 maintenance of the well or for treatment activities. 



Production tubing - Pipes placed within the casing and extending to various 

 levels within the well, through which oil and gas flow to the sur- 

 face. 



Prograde - To build up sedimentary materials along a beach face due to the 

 shoreward transport of sand caused by wave action. 



Push method - A method of pipeline installation that involves assembling the 

 pipe at a stationary point and then pushing the entire string of 

 pipe along the right-of-way from the assembly point. 



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