To ensure that the safety of oil production in normal winter, we have to oil wells annually implement wellhead insulation work, wellhead box processes, equipment warm. At present, box insulation commonly used way is to use the power of the wellhead electric heater. After searching and searching hard technical staff, to find a new low-power electric heater - new low-power silicon rubber heating plate.
1 Introduction
Oil Production Plant in electric heater used at this stage is a metal tube wellhead wellhead heater power.
Its main feature is the large power, high heat, and its two-piece power of 800W, a year incubation period is 4.5 months, the power consumption of 2592 degrees single well; the heat, often because of installation in the well put the child's mouth and put wellhead box roasted bad, and wire insulation joints poor security risk. So the technical staff through research to find a new type of silicone rubber low-power electric heating panels.
2 Principle and Structure
Silicone rubber is a new type of polymer elastic material with excellent high temperature performance (250-300 ℃) and low temperature resistance (-40-60 ℃), with excellent elasticity and permanent deformation properties. Special silicone rubber also has oil resistance.
Electric performance: Even short-circuit combustion silica remains insulator, which continue to work to ensure that the electrical equipment.
Surface properties is: stick to many materials, it can play a role in isolation. It is because of the silicone rubber has many excellent performance, so widely used. It is composed of the power cord, the silicone rubber layer, the heating resistor wire, the insulating layer, the silicone rubber constituting the insulating layer and the aluminum sheet.
How it works: the fixed power of resistance wire spiral wrapped in silicone rubber, both to generate heat after power, while the presence of heat insulation, the insulating layer so that the resulting resistance wire transfer to most panel direction, vulcanized or bonded Behind aluminum silicone rubber layer that is amorphous substrates, and is an excellent heat conductor, with the ambient temperature equilibrium quickly, and will not produce high surface temperature, so as to protect the installation surface from high temperature hazards, but also manufacture eyelets, play a fixed role at the wellhead box wall.
3 test cases
Think of the prospects for its application in the oilfield insulation, has been actively and manufacturers to get in touch, and requires manufacturers to provide samples tested in my fields, so we proceed to the product application fields feasibility study test.
Its experimental purposes: to determine the low-power electric heating panels can be applied to the insulation oilfield wellhead, the wellhead to replace the original high-power electric heater.
We know that, in order to let the wellhead instead of the original high-power electric heaters, must meet the following conditions:
(1) better electrical performance, high safety factor;
(2) the heat insulation to meet the requirements of oilfield wellhead while smaller energy consumption;
(3) there is a certain strength, not damaged, long life;
(4) easy to install, does not affect or less affect the original wellhead flow.
The main pilot projects: electrical performance test, water, oil test, destructive test
Test procedure:
First, we want to select test sites, it should meet the following conditions: Keep away from oil and gas accumulation zone; to provide reliable power supply; the actual production environment in line with oil wells; facilitate admission monitoring and test data. The final selection of the electric heating plate installed in the open air outside the X Team X number of station area ten meters of a wellhead box wall. In order to ensure test security, test power installed short-circuit protection switch.
3.1 In order to test the electrical safety performance of the heater, we were it made the following test:
(1) Hydrocarbon resistance test: After normal working condition, the crude oil drops on a hot plate, and the use of anti-gas station, be purged, it is surrounded by a high concentration of combustible gas, test duration 3.5 hours, no oil droplets on a hot plate and gas burning fire explosion dangerous phenomenon.
(2) Insulation resistance test: When the heating plate is working properly, use test pencil, multimeter to judge whether there is leakage, electrification, and in the case of security measures in place, the electrical heating plate is immersed in the rain, up to 10 The long hours, the timing of the measurement process found no leakage phenomenon.
(3) mechanical destructive tests: electric heating plate lifting working from the ground 1.5 meters, free-fall, the heating plate surface and observe normal working conditions. Hold both ends of the heating plate, 120 degrees (radians) folded several times to observe the surface of the heating plate and working conditions remain normal. To supply large joints bending strength was observed between the substrate and the line have light microfracture.
To get the new electric heating plate instead of the original high-power electric heaters, as well as one of the most fundamental problem is not resolved, it is that it can provide the normal production of oil must be some heat it?
So first of all we need to know an oil well without artificial heat, temperature can normally produce what is needed is how much, the following table is a random sample of two wells in mid-October, when the wellhead is not insulate various parts of the temperature data.
3.2 heat insulation to meet the requirements of oilfield wellhead
Power wellhead heater current use in the field in three sizes: 500W, 800W, 1000W three, and silicone rubber electric heating plate has 150W and 200W.
By actual test wellhead has been installed in power wellhead wellhead box heater temperature is 36 degrees, the temperature inside the box wellhead installation silicone rubber electric heating plate is 27 degrees. The freezing point of crude oil at 18 degrees, cold transmission oil temperature of 22 degrees. Both specifications are able to meet the oil wellhead heater insulation requirements.
3.3 Stability Test
After installing electricity, the use of non-contact infrared thermometer timing measurements heating plate heat surface, wire connectors, wellhead box wall temperature and ambient temperature.
Through long-term temperature test was observed from summer to winter, at different times, in different weather conditions, after prolonged sun exposure, wind and rain, water and gas purge invasion measured temperature experiments under the circumstances, the heating plate is stable, normal operation positive temperature between 110 ~ 165 ℃, the back temperature 45 ~ 65 ℃, no not hot, high temperature and other conditions, proves that electric heating plate has a very good stability.
4 usage and effects
By the above these simulations, we see this electric heating plate with good operational stability; higher insulating effect; has a certain resistance to mechanical damage ability, there is a more reliable security, can be used in the field .
We also require manufacturers to improve the power supply line connector. Then mounting a single well field test, manufacturers will soon improved to electric heating plate.
So we will be in the September 13 improved electric heating plate installed two teams on the two wells xx xx number stations, where XX wells installed 200W, XX wells installed 150W, due to the volume of new heating plate small, so very easy to install, do not change any of the wellhead equipment.
By comparing the above data, the power of the electric heater several different measured at different temperatures, a high power electric heater insulation box in the measured temperature, for winter conditions require insulation, but several different electric power heater terminals are aging, they are not available explosion-proof function, such as insulation box contains gas prone to fires, which for winter production safety security risk. 200-watt power explosion silicone rubber electric heating plate temperature measured value, numerical stability, when measured with oil cold transport temperature quite 20 ℃. With explosion-proof performance and safety, and in line with our oilfield winter insulation safety requirements.
5 Conclusion
Overall, this new silicone rubber low-power electric heating plate Its salient features are:
(1) a proof of good safety performance;
(2) energy-saving effect, low cost;
(3) to reduce the workload.
Economic and social benefits (if the whole operation area after promotion, the annual electricity savings of 504 000 degrees) worthy of promotion within the scope of the entire field.
