What Does Drill-In Fluid Mean?
Drill-in fluid is a type of drilling fluid designed especially for drilling through the reservoir section of a wellbore. It delivers all the properties of a drilling fluid, but does not damage the formation. Drill-in fluid is designed to protect the pay zone during wellbore construction, maximize the recovery of hydrocarbons and make cleaning easier. It also lowers the overall cost of completion of the wellbore and optimizes the rate of production.
Drill-in fluid is also known as drill-in mud.
Trenchlesspedia Explains Drill-In Fluid
Drill-in fluid is different from regular drilling fluid in that it is designed specifically to minimize skin friction, improve productivity and prevent damage to the formation. Drill-in fluid also helps in successful drilling of the reservoir zone, maximizes production and facilitates well completion.
Since every reservoir is different, core samples are analyzed to design a drill-in fluid. The drill-in fluid is designed to match the reservoir’s salinity, water hardness, mineralogy, pH and emulsion-forming abilities. This helps in preventing problems such as clay swelling, precipitate formation, emulsions and scaling — all of which can negatively impact production rates. A drill-in fluid resembles a completion fluid such as brine, containing only selected solids of appropriate size, polymers and additives necessary for carrying cuttings and for filtration control.