A combination method for detection and evaluation of production string in gas storage facilities to enhance the safety of injection and production in oil and gas wells

The traditional wellbore integrity detection and evaluation technology struggles to keep up with the long-term stable production needs of injection and production wells in gas storage due to such limitations as limited detection items and missed detection. To this end, a combination method for detection and evaluation of wellbore integrity integrating multiple detection technologies including gas dynamic logging, electromagnetic inspection logging, gamma-neutron flaw detection logging and neutron-gamma spectrum logging was proposed, and a comprehensive evaluation method for the residual strength and remaining life of the production casing based on the test data was proposed as well. The field application results in Nanbao No.1 gas storage shows that this technology can not only accurately position the leakage points, detect the corrosion status of the casing and check the gas accumulation area outside the casing, but also effectively evaluate the residual strength and remaining life of the production casing, which realizes the comprehensive and thorough detection and evaluation of the wellbore integrity, and lifts the limitations of limited detection. Compared with the traditional method, two more detection items are added: gas dynamic logging and neutron-gamma spectrum logging, which significantly improves the comprehensiveness and efficiency of the production string detection in gas storage. Research and field tests show that this technology can accurately identify the defect type and location of the wellbore, and can scientifically evaluate the residual strength and life of the production string under different working conditions based on the detection data, which provides a guiding basis for gas storage injection and production production, and also provides technical support for reservoir construction.