Flowing Liquid 380VAC Mineral Insulated Heaters For Fluid Viscosity

Product Specification

Downhole Electric Heater For Fluid Viscosity And Wax Precipitation Decreasing

Downhole Electric Heater for Fluid Viscosity and Wax Precipitation Decreasing is ideal for problem wells dealing with fluid viscosity and wax precipitation. This down-hole heater technology is currently fully commercialized for optimization schemes including well bore and near well bore heating with 4000 installations. The heavy oil wells of the oil fields (s) often require the use of the downhole electric heater for heating. Due to high temperature, high pressure and sand abrasion, the requirements for the safety, reliability, and service life of the electric heater are very high.

We now recommended the downhole electric heater that is manufactured using the latest domestically made MI heating cable. The product is capable of resistance heating with a simple circuit system. Moreover, it has such technical characteristics as resistance to high temperature (up to 600℃), high mechanical strength and low heat surface load

The downhole electric heater may be designed to any operating voltage. The power transmission cable of the downhole electric heater (use the proven flat cable of the submersible pump)is used to transmit power and give off heat at a small power level reasonably along the outer wall of the oil pipe. Such a combination provides a real solution to the technical problems such as pump suction of the heavy bodied oils at the bottom of the oil well and the electric heating of the outer wall of the oil pipe.

1. There are 2 application combinations of electric heating of outer wall of oil well pipes

1. Downhole electric heater (See Figure 1)

2. Electric heating of the outer wall of the oil pipe+ downhole electric heater (See Figure 2)

2. General technical requirements for electric heating of the outer wall of the oil pipe

Bound onto the outer wall of the oil pipe for downhole operations at an interval of every 10m

Heating depth:1800m; Oil temperature at the wellhead: 60--80℃; Heating power: 50—1000Kw;

Power voltage: 3-phase 1140/660 VAC; or 660/380VAC; 380/220 VAC;

General technical requirements for the downhole electric heater:

Upper/lower fixing connection joint TBG2-1/2;

Heating depth—connected to the electric submersible screw pump; downhole oil temperature: 115℃; heating power: 50—1000Kw;

Power voltage: 660/380/220 VAC;

III.Principles

The entire flat cable of the submersible pump is metal armored, high-temperature resistant and corrosion-resistant and uses the pure resistance of the core wire for heating and conductivity. Bounded on the outer wall of the oil pipe in the well until the packer top required by the electric submersible screw pump structure (or the required depth) is reached, it uses the commercial power voltage, which is connected to the flat cable of the submersible pump to give off heat evenly to heat the oil pipe in the well, and heat the oil in the pipe evenly through the oil pipe in the well. (The voltage regulator may be used to increase the commercial power voltage).

The flat cable of the submersible pump connects the commercial power voltage to the downhole electric heater (made using the metal MI heating cable) to give off heat at a high power level in a centralized manner, and the oil at the bottom of the well is heated through convection heat exchange to increase oil temperature and reduce oil viscosity and enable the electric submersible pump to suck up the oil.

IV. Description of the technical scheme

The final installed electric heating system in the well is shown in the figure below:

Figure 1. Schematic of the downhole heating device

Application example:

1.Basic calculation data: oil field well number: CB243A-6#; CB243A-3#; well depth: 2000m.

Bushing diameter: 273.05mm; oil pipe diameter: 177.8mm

The calculations parameters of the well are as follows:

Daily crude oil production: 50T

Depth under the pump: 1250m

Temperature rise from heating and viscosity reducing under the pump: 15℃

The required length of the heating section in the well is : 1250m

Geothermal gradient: 3.9 ℃/100m

Power of the downhole electric heater under the pump: Kw

Radiating supplementing power of the well bushing: 40w/m

2.Select the flat cable of the submersible pump (electric heater):

Total calculated electric heating power 72 Kw,(downhole 21 Kw; shaft wall: 51 Kw)

Voltage adopted: 660/380VAC 3-phase, 4-wire; operating phase current: 63.2A

(Serial voltage distribution: downhole electric heater 110VAC; shaft wall: 270VAC;)

Model of the flat cable of the electric heater of the shaft wall: :QYEQ-3 3X6mm2; quantity: 1 piece;

Out dimension: 8.4X30mm; the metal jacket is zinc plated steel belt; heating power: 40.4w/m;

Model of the heating cable of the downhole electric heater: MICN-C 16C8/165/7000/110/G1/2; quantity: 3 pieces

Outer diameter: 5.3mm: type of the metal jacket: white copper; unit heating: 42.4w/m

Surface heating strength of the heating cable of the electric heater: 0.255 w/cm2 (may ensure that the heavy bodied oil will not be carbonized; capable of dry burning in oil with gas);

Wound into the electric heater. There is an anti-abrasion reinforcing bar outside the radiating orifice plate; length: 6m; with Φ140mm box-type centering device at the two ends; can withstand the guide abrasion with the well wall when lowered into the well.

3.Temperature control:
Changed to the cold-resistant soft cable when exiting the wellhead, which is led into the electric control box to allow for power transmission and temperature monitoring. The temperature electric control box is of the outdoor, weather-proof and non-explosion-proof type, and shall be located in the safe area.

The temperature settings of the temperature controller may be set on the site freely. The upper temperature limit of the factory is 82℃ and the lower temperature limit 78℃.

The temperature sensor is installed in the oil outlet pipe outside the oil nozzle, based on the temperature of which automatic control of electric heating operation is carried out.

4.Safety performance:

The flat cable of the submersible pump threaded into the pipe has high mechanical strength, is bound onto the outer wall of the oil pipe forming an integral whole with the oil pipe, and may withstand the abrasion with the shaft wall when lowered into the well. The oil pipe and cable fasteners in the well bear the weight of the flat cable of the submersible pump. The oil field may perform operations in the oil pipe without restrictions.

The maximum long-term operating temperature of all electric heating equipment in the well is +180℃; it is safe and reliable with a long service life.

The electric heater allows for easy installation, may be removed for repeated installation and use in accordance with the operation specification.

Fourth, technical specification

1. Model meaning

2. Technical data

The main technical data are shown in Table 1.

Table 1 Technical Data and Outer Dimension Sheet for Vertical Electric Heater

Table 2 Technical Data and Outer Dimension Sheet for Horizontal Electric Heater