Flowing Liquid 380VAC Mineral Insulated Heaters For Fluid Viscosity

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

Model	Rated Power (Kw)	Rated Voltage (V)	Rated Current (A)	Power Phase	Outer Dimension(mm)			Body Weight (Kg)
					h1	H	D	6.3 MPa	4.0 MPa	2.5 MPa
YDRQ-3/220/L	3	220	13.5	1	180	720	φ219	165	105	90
YDRQ-5/220/L	5	220	22.5	1	180	860	φ219	175	120	105
YDRQ-7.5/220/L	7.5	220	34	1	180	1100	φ219	190	130	115
YDRQ-10/3/380/L	10	380	15	3	400	1000	φ273	240	200	165
YDRQ-15/3/380/L	15	380	22.5	3	400	1474	φ273	280	240	210
YDRQ-20/3/380/L	20	380	30	3	544	1100	φ377	475	320	260
YDRQ-30/3/380/L	30	380	45	3	544	1544	φ377	530	370	290
YDRQ-50/3/380/L	50	380	75	3	544	1850	φ377	640	510	430
YDRQ-80/3/380/L	80	380	120	3	600	2425	φ500	930	700	510
YDRQ-100/3/380/L	100	380	150	3	648	1850	φ600	1200	960	710
YDRQ-150/3/380/L	150	380	226	3	648	2920	φ600	1550	1050	820
YDRQ-200/3/380/L	200	380	300	3	648	3200	φ600	1790	1240	900
YDRQ-250/3/380/L	250	380	375	3	822	3482	φ1000	5000	3800	2900
YDRQ-300/3/380/L	300	380	450	3	822	3850	φ1000	6200	4950	3240
YDRQ-600/3/380/L	600	380	910	3	910	4854	φ1200	8000	6900	5800

 

 

 

 

 

 

 

 

 

 

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

Model	Rated Power (Kw)	Rated Voltage (V)	Rated Current (A)	Power Phase	Outer Dimension(mm)				Body Weight (Kg)
					L	L1	L2	D	6.3 MPa	4.0 MPa	2.5 MPa
YDRQ-3/220/W	3	220	13.5	1	1100	750	450	φ159	85	55	45
YDRQ-5/220/W	5	220	22.5	1	1300	1000	750	φ159	100	60	50
YDRQ-7.5/220/W	7.5	220	34	1	1650	1300	1000	φ159	110	65	52
YDRQ-10/3/380/W	10	380	15	3	1460	1050	750	φ219	180	160	130
YDRQ-15/3/380/W	15	380	22.5	3	1720	1400	1200	φ219	200	170	140
YDRQ-20/3/380/W	20	380	30	3	2000	1620	1300	φ219	220	180	150
YDRQ-30/3/380/W	30	380	45	3	2210	1850	1340	φ219	240	190	160
YDRQ-50/3/380/W	50	380	75	3	2750	2200	1600	φ273	400	315	240
YDRQ-80/3/380/W	80	380	120	3	3550	3100	2100	φ377	735	560	490
YDRQ-100/3/380/W	100	380	150	3	2950	2400	1750	φ530	1000	750	580
YDRQ-150/3/380/W	150	380	226	3	3500	3000	2300	φ530	1185	850	640
YDRQ-200/3/380/W	200	380	300	3	4350	3800	2650	φ530	1350	1000	720
YDRQ-250/3/380/W	250	380	375	3	4100	3600	2800	φ630	1900	1450	1050
YDRQ-300/3/380/W	300	380	450	3	4100	3600	2800	φ630	1950	1500	1100
YDRQ-600/3/380/W	600	380	910	3	4500	4000	3200	φ1000	5100	3800	2200