JPS58198801A - Electrically insulating coating conduit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrically insulated coated conduit used when extracting underground hydrocarbon resources by electrical heating.

In the following explanation, hydrocarbon underground resources refer to bitumen contained in oil sands or tar sands.
umθn), and hereinafter referred to as oil unless otherwise specified.

In recent years, with the rise in the price of oil resources, serious consideration is being given to extracting oil from oil sand layers buried underground in countries such as Canada and Venezuela. This oil sand layer is usually located several hundred meters underground and is approximately 50 meters thick.
However, due to its viscosity, this oil cannot be extracted by pumping it up at room temperature.Currently, heated steam is injected into the oil sand layer to raise the temperature of the oil. , a method has been adopted in which the viscosity is lowered and pumped up. However, this method is inefficient and expensive, so as a more productive method, a conduit (steel pipe or stainless steel pipe) having a tip end vc1i [pole part] is buried so that the electrode part is located in the oil sand layer. Two such oil extraction conduits are connected to approximately 30-
The most common method is to install oil sands 200 meters apart, apply a voltage of several hundred to several thousand volts between both electrodes, raise the temperature of the oil sand layer using Joule heat, and lower the viscosity of the oil. has been considered.

Because the resistivity of the oil sand layer is several times higher than that of the upper stratum, the portion of the conduit buried in the stratum must be covered with an electrical insulator to prevent current from flowing through the upper stratum. If it is not coated with an electrical insulator, the current will flow through the strata and will be buried in the oil sand layer and will no longer flow between the fc electrodes. Accordingly, there is a rapidly increasing need to develop conduits coated with electrical insulators that can withstand use under these special conditions.

The following characteristics (A), (B), and (0) are required for this electrical insulator.

(A) Voltage resistance of several hundred to several thousand volts and at least 10”Ω-a not only at room temperature but also at temperatures that can reduce the viscosity of oil in the oil sand layer (approximately 300°C)
Have a volume resistivity value of m or more.

(B) Water contained in the oil sand layer is heated to a temperature (about 300° C.) that can reduce the viscosity of the oil sand layer, so it can withstand hot water of about 300° C.

(0) It must have mechanical strength to suspend four poles and mechanical impact strength to the extent that it will not be damaged by contact with the hole wall when the electrode with the tip of the 4' spear VC suspended is buried in the oil sand layer through the buried hole. .

The present inventors have developed a conduit coated with an electrical insulator that has all of the characteristics (A) to (0) above. A resin composition (I), or a resin composition Ql) obtained by adding an imidazole compound or a trifluoroboronate Zn complex to the resin composition (I), and a glass fiber having a silica component of 90 ts or more. They discovered that a conduit coated with an electrical insulator having all of the characteristics (A) to (0) above can be replaced by wrapping the prepreg around the outer circumferential surface of the conduit and heating and curing it, thereby completing the present invention. It arrived.

The epoxy resin used in the present invention has two or more epoxy groups in the molecule, and representative examples include:
In particular, bisphenol type epoxy resins represented by the following structural formula are mentioned.

υ The n of this bisphenol type epoxy resin is preferably up to 2. Its commercially available products include Epicote 828. Ebiko) 854 (all manufactured by Yuka Shell Epoxy Co., Ltd.), Aralgate GY-250
, Aralgate GY-280 (all manufactured by Ciba-Geigi).

Other epoxy resins other than the bisphenol epoxy resins mentioned above include novolak epoxy resins.

This novolak type epoxy resin preferably has a value of n up to 2, and commercially available products include Araldye (Araldai) KPN 1
138 (manufactured by Ciba-Geigi), DIN 431, D
EIN438 (Dow Chemical Company, USA!I) etc. can be opened.

Further examples include epoxy resins manufactured by Talesol Novolac.

In this cresol novolak type epoxy resin, n is up to 2 and m is up to 5. Commercially available products include Araldite 1ON1235 and Araldite EcN12'? 3
, Araldite 1280, Araldite 1299 (
(all manufactured by Chiba Gaiki), and all of which are suitable for use in the present invention.

As a vine hardening agent that reacts with these epoxy resins, Maruzen Resin M, a poly-para-vinylphenol resin, is used.
(Maruzen Sekiyu rig: Maruzen Resin MB (manufactured by Maruzen Sekiyu Co., Ltd.), which is a brominated poly-para-vinyl phenol resin, is also mentioned, and any of them can be suitably used in the present invention.

Specific examples of imidazole compounds include 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-
Methylimidazole, 2-ingropylimidazole,
2-undecylimidazole, 2-heptade□cylimitasol, 2-7 enylimidazole, 2-phenyl-
4-methylimidazole, 1-benzyl-2-methylimidazole, cyanethylated-2-methylimidazole, cyanethylated-2-ethyl-4-methylimidazole, cyanethylated-2-undecylimidazole, cyanoethylated-2 -Phenylimidazole, etc. Specific examples of boron trifluoride amine complexes include boron trifluoride monoethylamine, boron trifluoride dimethylanitone, boron trifluoride benzylamine, and boron trifluoride 1A-2-methylimidazole. It will be done.

As the glass fiber, a glass fiber having a silica content of 90 or more is used. The silica content of glass fiber is 90%
If it is less than 300° C., the surface of the glass fiber will be dissolved by hot water at 300° C., lowering the volume resistivity of the insulator and lowering its mechanical strength.

The prepreg can be made into an insulator by wrapping the prepreg around the outer circumferential surface of the conduit and then heating and curing it.

As the metal conduit, a steel pipe or a stainless steel pipe, which has relatively excellent corrosion resistance and good air conductivity, is suitable. The length of the conduit is determined depending on the depth of the underground oil sand layer, but is usually about 200 to 60 mm.
Approximately 0m is required.

Next, embodiments of the electrically insulating coated conduit of the present invention will be described.

FIG. 1 is a partial cross-sectional view of the distal end of an electrically insulating coated conduit. As shown in FIG. 1, after connecting the electrode (1) and winding the prepreg on the outer circumferential surface of the metal-friendly conduit (2), it is heated and cured, and an electrically insulating layer (3) is coated.

Generally, the length of the conduit (2) is required to be about 200 to 600 m, but since the length of each ordinary steel pipe or stainless steel pipe is 5 to 50 m, it is necessary to insert the tip into the oil sand layer. When it is inserted, it is inserted without joining.

FIG. 2 is a partial cross-sectional view of a joint of an electrically insulating coated conduit. As shown in FIG. 2, when joining a small conduit (2a) coated with an electrically insulating layer (3a) and a conduit (2b) coated with an electrically insulating layer (3'b), each conduit (
Taper screws (5) are cut at the ends of 2a) and (2b), and they are joined using a coupling (4). In that case,
In order to prevent electrical leakage from the joint, the surface of the joint, i.e. the coupling (4) and the end of the conduit, is further coated with an electrically insulating layer (3C).

Next, the method of coating the prepreg electrical insulating layer and its properties will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 Silica component with thickness 0, 20 mm, width 30 mm is 90
% or more of the glass fiber tape, Epikote 828 10
0 parts (parts by weight, hereinafter the same), 64 parts of Resin M, 37
A prepreg tape was prepared by impregnating it with a varnish consisting of 1 part of boron tsuride-2-methylimidazole, 155 parts of methyl alcohol, and 10 parts of methyl alcohol, followed by air drying and heating drying at 80°C. This prepreg tape was wound 8 times on the outer circumferential surface of the conduit in a half-overlapping manner, and then heated at 130°C for 1 hour for 15 minutes under the pressure applied by the heat shrink tape.
It was heat-cured at 0°C for 1 hour and at 180°C for 2 hours.

The tensile strength (kg/
cmQ) and dielectric breakdown voltage value (kv/mm) and its (1 rin) After immersing the insulating layer in hot water K at 300°C for 500 hours,
The tensile strength and dielectric breakdown voltage values measured at °C are shown in Table 1.

Examples 2 to 8 Composition of varnish for prepreg impregnation and heat curing conditions 8
An experiment was carried out in the same manner as in Example 1 except that the materials shown in Table 1 were used to form an electrically insulating layer on the outer peripheral surface of the conduit, and Table 1 shows the characteristics of the electrically insulating layer obtained.

Table 1 ℃ J)]] Next, conditions regarding the above-mentioned Examples will be further specified, and a comparative example will be explained.

Comparative Example 1 An experiment was conducted in the same manner as in Example 1 except that an E glass fiber tape with a silica content of 52% was used instead of a glass fiber tape with a silica content of 90 or more. A layer was formed. The characteristics of the obtained electrical insulating layer are shown as M2RVc.

Comparative Example 2 An experiment was conducted in the same manner as in Example 1 except that a tape made of 8 glass fibers with a silica content of 65% was used instead of a tape made of glass fibers with a silica content of 90% or more.
An electrical insulating layer was formed on i. Table 2 shows the properties of the electrically insulating layer obtained.

Comparative Example 3 Experiment was carried out in the same manner as in Example 1 except that 100 parts of alicyclic epoxy resin Chissonox 221 (manufactured by Chisso Co., Ltd.) and 100 parts of Resin M were used instead of the bisphenol type epoxy resin Epicoat 828. An electrically insulating layer was formed on the outer peripheral surface of the conduit. Table 2 shows the properties of the electrically insulating layer obtained.

Table 2 As is clear from the results listed in Tables 1 and 2, in the electrically insulating coated conduit of the present invention, the insulating layer has excellent electrical properties, mechanical properties, and hot water resistance.
It is suitable as a conduit used for extracting underground hydrocarbon resources by electric heating method.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of the tip of a nine-conductor tube coated with electrical insulation. FIG. 2 is a partial cross-sectional view of a joint of an electrically insulating coated conduit. In the figure, (2) ) (2a) and (2b) are conduits, (
3) , (3a) + (3b) and (3C) are electrically insulating layers. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno - Figure 1

Claims (1)

[Scope of Claims] (1) After attaching a fiber leg made of a resin composition made of epoxy resin and poly-rose vinyl phenol resin and a silica component of 90 or more to the outer peripheral surface of a metal conduit, heating is performed. Hardened electrical insulation coated conduit. (2) The electrically insulating coated conduit according to claim M1, in which the epoxy resin is a bisphenol type epoxy resin. (3) The electrically insulating coated conduit according to claim 1, in which the epoxy resin is a novolac type epoxy resin. (4) The electrically insulating coated conduit according to claim 1, wherein an imidazole compound or a boron trifluoride amine complex is added to the resin composition.