Hollow Rod Electric Heating Device

1. Application of the device:

With the gradual increase in the proportion of heavy oil and high pour point oil wells, our company has successfully developed a hollow sucker rod electric heating device to solve various technical problems encountered in the process of heavy oil and high pour point oil extraction, such as difficulty in lifting crude oil, heavy load on sucker rods, increased load on sucker rods, difficulty in descending sucker rods, and difficulty in pumping crude oil. This device can effectively solve various technical problems encountered in the process of high pour point and high viscosity oil extraction.

2.Device features

a、 Simple construction: After normal operation of the hollow sucker rod, the cable is lowered into the inner hole of the hollow sucker rod with a cable winch, and the circuit cable is connected. After preheating, the well can be opened, and it can be operated and pumped on the same day. 

b、 The ground setting is simple, easy to use, and easy to manage: compared with ordinary sucker rod wells, the ground equipment only adds a dedicated power supply device, and the structure is relatively simple. 

c、 The heating temperature is uniform, the thermal efficiency is high, and automatic temperature control can be achieved: due to the direct heating of the sucker rod body, the heat loss is small, and the entire process of heating the sucker rod can be achieved. 

d、 Due to the decrease in viscosity of crude oil after heating, the downward resistance of the pumping rod is reduced, which can increase the effective stroke of the plunger, improve pump efficiency, and extend the pump inspection cycle. 

e、 The structure is safe and reliable, with good repeatability: When inspecting the pump, only the cable winch is needed to lift the cable, and then the entire sucker rod is lifted out, and both the cable and sucker rod can be reused. 

f、 After the viscosity of crude oil decreases, the friction resistance of the sucker rod decreases, the upper stroke load of the pumping unit decreases, and the lower stroke speed increases, which can effectively improve the load condition of the pumping unit.

 3.Working principle and Device structure:

The hollow rod electric heating device is a cable inserted into the hollow sucker rod and forms a circuit with the sucker rod body. It is powered by AC power and uses the principle of internal skin effect to generate heat energy on the wall of the hollow sucker rod, heating the crude oil in the oil pipe throughout the process to increase the temperature of the crude oil in the oil pipe, reduce the viscosity of the crude oil, improve its fluidity, prevent wax deposition of the crude oil in the oil pipe, and effectively extract high pour point, high viscosity, and high wax crude oil.

4.Structural diagram of hollow sucker rod electric heating device

5.Parameters of hollow sucker rod electric heating device

a、Basic parameters of heating cable

 b. Technical parameters of hollow sucker rod

c. Basic parameters of power supply device:

(a) Input voltage: three-phase, 380V ± 5%, 50HZ (three-phase, 440V ± 5%, 60HZ);

(b) Output voltage: single-phase, adjustable from 300-900V; 

(c) Power supply factor: cos Ø ≥ 0.95;

(d) Three phase current imbalance: ≤ 10%

(e)Basic data and applicable heating depth table of power supply device