Method for detecting sealing quality of oil pipe at well head

Abstract

The invention discloses a method for detecting sealing quality of an oil pipe at a well head. The method comprises the steps of placing a packer to the thread connection part in the oil pipe by a lifting device, setting the packer by a high-speed booster pump and adding a detection medium in a sealed space, detecting the leakage value of the detection medium by the detection device, and inputting and recording a detection result by a recording device. By the method, the oil pipe can be detected at the well head, the result can serve as a basis for judging whether the sealing quality of the oil pipe in rigid connection is qualified or not and therefore the sealing quality of the oil pipe is improved greatly.

Description

technical field [0001] The invention relates to a wellhead detection method for oil pipe sealing quality, and belongs to the technical field of oil testing and testing the safety of downhole pipe strings. Background technique [0002] In the development of high-temperature and high-pressure sour gas fields in China, the completion string composed of tubing and permanent packers is often put into production. The existing problems are: 1. The tubing stays for a long time, and it is generally required to be used for more than 10 years after it is put into production; 2. After the packer is set, it cannot be operated in reverse, and if the tubing leaks due to poor thread seal quality, it cannot be compensated; 3. During the operation after the packer is completed, the downhole string will also be perforated, acidified, and sanded For reservoir reconstruction operations such as gas lift and gas lift, the tubing will bear a large pressure difference, and the sealing requirements a...

AI Technical Summary

Problems solved by technology

[0002] In the development of high-temperature and high-pressure sour gas fields in China, the completion string composed of tubing and permanent packers is often put into production. The existing problems are: 1. The tubing stays for a long time, and it is generally required to be used for more than 10 years after it is put into production; 2. After the packer is set, it cannot be operated in reverse, and if the tubing leaks due to poor thread seal quality, it cannot be compensated; 3. During the operation after the packer is completed, the downhole string will also be perforated, acidified, and sanded Reservoir reconstruction operations such as , gas lift, etc., the tubing will bear a large pressure difference, and the sealing requirements are very high

Therefore, "Inner Mongolia Petrochemical Industry" published a "Application of Gas Seal Detection Technology in High Pressure Deep Wells" in Issue 23 of 2010. The main problems of this gas seal detection technology are: 1. This technology can only detect leakage exceeding 2x10 -7 bar.ml / s, the detection accuracy cannot fully ensure that the threaded thread has sufficient tightness to ensure the safety of the pipe string after the gas well is put into production

2. It uses a high-pressure accumulator as a pressurization source. Due to the limited conditions for on-site use and maintenance, after long-term use, the accumulator as a high-pressure container has a risk of leakage. Therefore, special and safe devices must be installed for the accumulator on site. The storage area causes inconvenient use and high risk; 3. The mixed gas used for detection is directly mixed on site, and the gas ratio of different components fluctuates greatly every time it is injected, which has a certain impact on the judgment of later leak detection

[0003] Therefore, there is currently no safe and high-precision method to detect the sealing quality of the tubing before the packer is set, and there is an urgent need for a method that can detect the sealing quality of the tubing after the tubing is connected at the wellhead

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