How to choose the right downhole motor part 2

The Influence of the type of mud for downhole motor

If used in salt water mud, corrosion resistance of the conventional rotor less effective, lead to the mud motors failure in serious condition, also direct impact on the life of the mud motors.

Corrupted Rotor

Rotor coating:

Surface spray coating:

To adapt mud motor to a variety of drilling mud , but costs are high, the coating is 10 times than the normal, more saturated salt water mud conditions in use. 

Chrome coating rotor

Thick rotor coating process:

Common technology on chrome-coating depending on the surface shape of the rotor creates large tolerance between actual streamline and the academic streamline of the rotor, which will reduce the efficiency of the power section. Special chroming coating technics by landrill will control the rate between apex and vale of the coating control to 1:3, Best of up to 1:1

Rotor coating technology

High-temperature and oil resistant applications reports

User :XXX drilling  company 

Place :CHINA

Well type :horizontal 

Lithology:Yingcheng, gray mass conglomerate 

Oil content: Diesel fuel 86% 

Downhole Model:High-temperature 150℃、oil resistant 

Tricone bit selection :HUGHES Tricone bit 6"MXDS55DX） nozzzle：3Xф16

MUD MOTOR USING REPORT

Choose right mud motor according to the flow rate and the power of Mud pump

Hollow rotor mud motor

To increase hydraulic horsepower and upward speed of mud stream, rotor is manufactured into hollow rotor with nozzles. Thus, motor total flow rate is equal to the sum of the flow rate  through seal  cavity and rotor. Each type of motor has  its own recommended  maximum and    minimum flow rate value. If flow rate  is too high, rotor may be running at over speed, earlier   damage would occur onto stator and rotor. If it is too low, motor will stop operating. Therefore,  the flow rate through seal cavity shall be ensured or even higher than the recommended            maintenance value, while selecting nozzle size. Only in this way, can mud motor be kept in normal   operation. 

When mud density, nozzle size and total flow  rate is a constant value, the flow rate through nozzle and seal cavity always changes with the load. On bit leaving hole bottom ,the load is approximately zero . Whereas, the flow rate becomes minimum through nozzle on the rotor, but the flow rate becomes maximum through the seal cavity. While the bit dropping down, motor pressure loss will continuously increase, and the flow rate through rotor nozzle will become higher, but the flow rate through the seal cavity will become lower.

The principle of choosing ABH or fixed mud motor

1. Stepless adjustment of sub-grade and two structural adjustment.

2. Adjustable Bend Housing mud motors advantages:

The angle of housing can adjust at wellhead of Drilling platform Motors can be used either for straight use as a bend motors

Adjustable bend housing:

Our company is the production of adjustable bent housing mud motor with adjustable angle range of 0 ° -2 °, 0 ° -3 °, 0 ° -4 °.