Downhole Motors
The idea of using downhole motors to directly turn the bit is not a new one.
One of the first commercial motors was turbine driven. The first patent for
a turbodrill existed in 1873. The USSR focused efforts in developing
downhole motors as far back as the 1920’s and has continued to use motors
extensively in their drilling activity. After 1945, the West focused efforts
more on rotary drilling, but field applications for downhole motors has
increased spectacularly from the 1980’s onwards.
A turbine consists of a multistage vane-type rotor and stator section, a
bearing section, a drive shaft and a bit rotating sub. A “stage” consists of a
rotor and stator of identical profile. The stators are stationary, locked to the
turbine body, and deflect the flow of drilling mud onto the rotors which are
locked to the drive shaft. As the rotors are forced to turn, the drive shaft is
also forced to turn, causing the bit sub and the bit to rotate
The idea of using downhole motors to directly turn the bit is not a new one.
One of the first commercial motors was turbine driven. The first patent for
a turbodrill existed in 1873. The USSR focused efforts in developing
downhole motors as far back as the 1920’s and has continued to use motors
extensively in their drilling activity. After 1945, the West focused efforts
more on rotary drilling, but field applications for downhole motors has
increased spectacularly from the 1980’s onwards.
A turbine consists of a multistage vane-type rotor and stator section, a
bearing section, a drive shaft and a bit rotating sub. A “stage” consists of a
rotor and stator of identical profile. The stators are stationary, locked to the
turbine body, and deflect the flow of drilling mud onto the rotors which are
locked to the drive shaft. As the rotors are forced to turn, the drive shaft is
also forced to turn, causing the bit sub and the bit to rotate
