Device for Removing and Preventing Paraffin by Using Electric Heating Generated from Skin Effect-based Natural Gas Electricity and Application thereof

Abstract

A device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity and an application thereof are disclosed, and the device comprises a natural gas collection portion, a natural gas electricity generation portion and a device for removing and preventing paraffin by using electric heating powered by the natural gas electricity generation portion; the natural gas collection portion is used to collect and separate natural gases discharged from a wellbore; the natural gas electricity generation portion generates electricity with natural gases. The power source required by the electric heating of the steel armored cable of the present invention comes from the natural gas electricity generation portion, and the air source required by the natural gas electricity generation portion can be obtained directly from the associated gases extracted from an oil well.

What is claimed is: 
     
         1 . A device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity, characterized in that the device comprises a natural gas collection portion, a natural gas electricity generation portion and a device for removing and preventing paraffin by using electric heating powered by the natural gas electricity generation portion;
 the natural gas collection portion is used to collect and separate natural gas discharged from a wellbore; and   the natural gas electricity generation portion generates electricity with the natural gas.   
     
     
         2 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 1 , characterized in that the natural gas collection portion comprises an oil-gas metering station, a joint processing station and a natural gas purifying station that are successively connected to the wellbore. 
     
     
         3 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 2 , characterized in that an oil storage tank is arranged to be connected with the joint processing station. 
     
     
         4 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 2 , characterized in that a gas storage tank is arranged to be connected with the natural gas purifying station. 
     
     
         5 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 1 , characterized in that the natural gas electricity generation portion comprises a natural gas generator set and a power frequency electric heating control cabinet that are connected; and the power frequency electric heating control cabinet is used to control the device for removing and preventing paraffin by using electric heating. 
     
     
         6 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 5 , characterized in that the device for removing and preventing paraffin by using electric heating comprises a steel armored cable extending into the wellbore sealedly through a Christmas tree, and the steel armored cable is connected with the power frequency electric heating control cabinet. 
     
     
         7 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 6 , characterized in that the steel armored cable comprises a steel armored sheath, an insulating material layer, a polytetrafluoroethylene layer and a cable core wire that are successively arranged from outside to inside. 
     
     
         8 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 7 , characterized in that the steel armored sheath is a contiguously seamless steel tube. 
     
     
         9 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 6 , characterized in that the device for removing and preventing paraffin by using electric heating further comprises a wellhead high-pressure sealing system arranged on the top of the Christmas tree; and the wellhead high-pressure sealing system comprises a pressing cap, a sealing packing, a spring, a wedge disc and a cable clamping plate that are passed through successively by the steel armored cable. 
     
     
         10 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 9 , characterized in that a suspension connector is further arranged on the top of the pressing cap. 
     
     
         11 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 6 , characterized in that the device for removing and preventing paraffin by using electric heating further comprises a centralized heater that is arranged on a tail end of the steel armored cable stretching into the well, the centralized heater comprises a resistance wire connected with the steel armored cable, and a thermal conductive insulating layer is arranged outside of the resistance wire. 
     
     
         12 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 11 , characterized in that the steel armored cable is connected respectively with the resistance wire and the thermal conductive insulating layer through a double-ferrule fitting. 
     
     
         13 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 11 , characterized in that the thermal conductive insulating layer is a thermal conductive silica gel layer. 
     
     
         14 . The device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 1 , characterized in that the natural gas electricity generation portion comprises a natural gas generator set and multiple sets of power frequency electric heating control cabinets; the multiple sets of power frequency electric heating control cabinets are used for correspondingly controlling the devices for removing and preventing paraffin by using electric heating mounted in a plurality of wellbores respectively. 
     
     
         15 . A working method of the device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 7 , characterized in that the working method comprises the following steps:
 1) the natural gas collection portion collects and separates out the natural gas in the wellbore and transmits the natural gas to the natural gas electricity generation portion for electricity generation;   2) the natural gas electricity generation portion supplies variable-frequency power for the device for removing and preventing paraffin by using electric heating:   the power frequency electric heating control cabinet outputs variable-frequency power, a live line of the power frequency electric heating control cabinet is connected with the cable core wire of the steel armored cable; and   a zero line of the power frequency electric heating control cabinet is connected with the steel armored sheath of the steel armored cable;   so that the cable core wire and the steel armored sheath form a loop, and thermal energy can be generated on an outer wall of the steel armored sheath via the skin effect, so as to remove paraffin or prevent paraffin from forming in the wellbore by crude oil.   
     
     
         16 . The working method of the device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 15 , characterized in that the method further comprises steps of lowering the steel armored cable into the wellbore and lifting the steel armored cable out of the wellbore:
 3) when the steel armored cable is lowered into the wellbore, the spring opens the wedge disc, the steel armored cable enters the wellbore, and then the steel armored cable, the pressing cap, the sealing packing, the spring and the wedge disc form a high-pressure wellhead seal, to achieve a high pressure sealing effect in the lowering process and a heating process of the steel armored cable;   4) when the steel armored cable is lifted out of the wellbore, the spring resets to close the wedge disc to prevent oil-gas fluid from spewing out along the wellhead.   
     
     
         17 . The working method of the device for removing and preventing paraffin by using electric heating generated from skin effect-based natural gas electricity according to  claim 15 , characterized in that the method further comprises a step for a condition when the steel armored cable accidentally drops into the wellbore:
 5) when the steel armored cable accidentally drops into the wellbore, the spring resets to close the wedge disc to prevent oil-gas fluid from spewing out along the wellhead.