Single horizontal well gravity oil drainage production device and method of using downhole steam generation

Abstract

The invention relates to a single horizontal well gravity oil drainage production device and method of using downhole steam generation. The continuous coiled tubing string is lowered into a horizontal well, the combustion aided agent, fuel and water are sent downhole through corresponding paths to be heated to the supercritical state of water by the preheater. Continuous combustion is conducted in the steam generator to produce water vapor and carbon dioxide. Steam is injected into an oil formation through a steam generator outlet, and heated crude oil and steam condensate water enter the horizontal well downward and flow into the oil production pump to be lifted to the ground. The single horizontal well gravity oil drainage production device and method are reliable in principle, steam injection and oil production lifting work cooperatively in the same horizontal well, saving production cost.

What is claimed is: 
     
         1 . A single horizontal well gravity oil drainage production device using downhole steam generation, comprising a high-temperature-resistant dual-tube injection-production well head, and a downhole steam generation and injection system and an oil production lifting system that are lowered into the hole through the well head, wherein the steam injection system consists of a continuous coiled tubing string, a water tank, a fuel tank, a combustion aided agent tank, a preheater, an igniter, a steam generator, a power supply, and a test signal receiver, and the continuous coiled tubing string comprises a path for conveying the combustion aided agent, fuel, and water, and a path for conveying power and receiving test signals; wherein the continuous coiled tubing string is lowered into the horizontal well through the injection-production well head, is connected to the water tank, the fuel tank, and the combustion aided agent tank on the ground, and is connected to the preheater, the igniter, and the steam generator in a downhole liner in order; wherein the continuous coiled tubing string is further connected to the power supply and the test signal receiver located on the ground; and wherein the oil production lifting system comprises an oil tube and an oil production pump. 
     
     
         2 . The single horizontal well gravity oil drainage production device using downhole steam generation according to  claim 1 , wherein the oil production pump is a sucker-rod pump or an electric submersible pump. 
     
     
         3 . A single horizontal well gravity oil drainage production method using the device according to  claim 1 , wherein the process comprises the steps of: the continuous coiled tubing string is lowered into the horizontal well through an injection-production well head, the combustion aided agent, fuel and water are sent downhole through corresponding paths of the continuous coiled tubing string after being pressurized, respectively, heated to the supercritical state of water by the preheater, mixed and ignited, continuous combustion is conducted in the steam generator to produce water vapor and carbon dioxide, steam is injected into an oil formation through a steam generator outlet to form a steam chamber, and heated crude oil and steam condensate water enter the horizontal well downward and are lifted to the ground by continuously flowing into the oil production pump; the temperature and pressure of the well are transmitted to the test signal receiver on the ground through the continuous coiled tubing string, the continuous operation of the downhole steam generator and the control of the operating parameters of the oil production process are realized through ground regulation, and steam injection and oil production lifting work cooperatively in the same horizontal well. 
     
     
         4 . A single horizontal well gravity oil drainage production method using the device according to  claim 2 , wherein the process comprises the steps of: the continuous coiled tubing string is lowered into the horizontal well through an injection-production well head, the combustion aided agent, fuel and water are sent downhole through corresponding paths of the continuous coiled tubing string after being pressurized, respectively, heated to the supercritical state of water by the preheater, mixed and ignited, continuous combustion is conducted in the steam generator to produce water vapor and carbon dioxide, steam is injected into an oil formation through a steam generator outlet to form a steam chamber, and heated crude oil and steam condensate water enter the horizontal well downward and are lifted to the ground by continuously flowing into the oil production pump; the temperature and pressure of the well are transmitted to the test signal receiver on the ground through the continuous coiled tubing string, the continuous operation of the downhole steam generator and the control of the operating parameters of the oil production process are realized through ground regulation, and steam injection and oil production lifting work cooperatively in the same horizontal well. 
     
     
         5 . The single horizontal well gravity oil drainage production method according to  claim 3 , wherein the steam is generated from the process that organic fuel produces in a chemical reaction with oxygen under supercritical conditions of water, and generates carbon dioxide and water during combustion, which is accompanied by a large amount of heat release, the continuously entering fuel makes the supercritical state persist, and the newly entering water continues to be converted into steam, thereby achieving continuously generating high-temperature steam. 
     
     
         6 . The single horizontal well gravity oil drainage production method according to  claim 4 , wherein the steam is generated from the process that organic fuel produces in a chemical reaction with oxygen under supercritical conditions of water, and generates carbon dioxide and water during combustion, which is accompanied by a large amount of heat release, the continuously entering fuel makes the supercritical state persist, and the newly entering water continues to be converted into steam, thereby achieving continuously generating high-temperature steam. 
     
     
         7 . The single horizontal well gravity oil drainage production method according to  claim 3 , wherein the continuous operation of the downhole steam generator and the control of the operating parameters of the oil production process are realized through ground regulation, referring to the production method in which the injection and production process is regulated in accordance with the temperature and pressure control rule required by the downhole steam-assisted gravity oil drainage to achieve the simultaneous operation of steam injection and oil production in the full-horizontal well section of the same well. 
     
     
         8 . The single horizontal well gravity oil drainage production method according to  claim 4 , wherein the continuous operation of the downhole steam generator and the control of the operating parameters of the oil production process are realized through ground regulation, referring to the production method in which the injection and production process is regulated in accordance with the temperature and pressure control rule required by the downhole steam-assisted gravity oil drainage to achieve the simultaneous operation of steam injection and oil production in the full-horizontal well section of the same well. 
     
     
         9 . The single horizontal well gravity oil drainage production method according to  claim 3 , wherein the method is used for oil reservoirs with a well depth of 1,000-3,000 meters or a depth of more than 3,000 meters. 
     
     
         10 . The single horizontal well gravity oil drainage production method according to  claim 4 , wherein the method is used for oil reservoirs with a well depth of 1,000-3,000 meters or a depth of more than 3,000 meters. 
     
     
         11 . The single horizontal well gravity oil drainage production method according to  claim 3 , wherein an oil production method for intermittent injection can be carried out as required. 
     
     
         12 . The single horizontal well gravity oil drainage production method according to  claim 4 , wherein an oil production method for intermittent injection can be carried out as required.