BHA-what does it means
• Bottom hole assembly (BHA) • The BHA is made up of: a drill bit, which is used to break up the rock formations; drill collars, which are heavy, thick-walled tubes used to apply weight to the drill bit; and drilling stabilizers, which keep the assembly centered in the hole. • The BHA may also contain other components such as a downhole motor and rotary steerable system, measurement while drilling (MWD), and logging while drilling (LWD) tools. The components are joined together using rugged threaded connections. • Short "subs" are used to connect items with dissimilar threads.
Type of the Bits
Drill collars
Drilling Stabilizers and Reamers
Measurement while drilling (MWD), and logging while drilling (LWD) tools. Logging While Drilling (LWD) is a technique of conveying well logging tools into the well borehole downhole as part of the bottom hole assembly (BHA). LWD tools work with its Measurement While Drilling (MWD) system to transmit partial or complete measurement results to the surface via typically a drilling mud pulser or other improved techniques, while LWD tools are still in the borehole, which is called "Real Time Data". Complete measurement results can be downloaded from LWD tools after they are pulled out of hole, which is called "Memory Data".
LWD MWD
Short "subs"
Drill String
