Study On Downhole Petroleum Gas Explosion Character For Air Injection EOR Process

At present,any oilfields in our country have entered the mid-late stage of reservoir exploration, attend by many problems, such as high water cut of oil wells , high input -output ratios,tapping the potential reserves has many difficultise by general water-injection technology and so on , and the other enhanced oil recovery(EOR)technology is limited. Domestic and overseas practical applications have proved that in low permeability light oil reservoir air injection is a new and creative EOR technology, but the security problem is always the focus in academic circle,and it effects directly the spread and application in our country, then a laboratory study, risk analysis and safety assessment, monitoring sacheme and safety control measures and safety control system have greatly practical significance of the successful implementation of air injection or air - foam low temperature oxidation technology. This paper major research on the gas explosion limits and critical oxygen content of flammable gas CH4 under different conditions self-designed and built the experiment apparatus of hydrocarbon explosive properties. On the basic of the measure the gas explosion limits and critical oxygen content,. And according to the risk theory and domestic and overseas practical applications, this paper researches and analysis the main risks existing in the process of air injection, includes yield manhole explosion, inject manhole explosion, air compressor failure and corrosions of shaft and pipelines. In our country the researches and application of air injection technology is in the preliminary stage, and the backup system is not perfection, not to say the systemic safety assessment and risk Analysis. The paper use FTA analysis to assess the risks of air Injection EOR Process, combine with the characteristics and practicality conditions, to find out the main risks and hazardous factors,and then constitute the protections and control measures, control the probability and degree of event under acceptable range,make safety control system for the application of air Injection in our country, and to accelerate the development and consummate of safety backup system.