Study On Air Drilling Downhole Explosion Risk Evaluation And Control Measures

With the development of drilling technology,air drilling technology received extensive attention because of its special technical advantages,its application has also been favored by domestic and foreign drilling companies.By its technical name,we can know that the drilling circulating medium of air drilling is air,with the advantages of easy to use and low cost.But security problems of this technology have become the focus of attention at home and abroad.Especially when drilling encountered reservoir,there is possibility of firing and expiosing of flammable gas in underground.Practice shows that the accident's consequences are very serious.Thus,underground blasting issue has become very difficult and we have to face.This thesis firstly conduct hazard identification for air drilling based on accident cross theory and combine with the theory of dangerous source analysis in modern security engineering for underground explosion problem in air drilling,in order to determine the most basic factors which cause security accident.Dangerous source of air drilling job is divided in two sorts: static and dynamic.Secondly,select fuzzy integrated judge method to make risk assessment on air drilling process combined with the features of air drilling itself.The assessment results display: security management must be paid attention and drilling technology must be improved in order to improve security index of air drilling technology.Then the thesis establish air drilling risk assessment system for the assessment with fire explosion as the most dangerous risk based on the method which assessment system is established home and abroad.The assessment results have shown that: the degree of risk of accidents in underground blasting is in the edge of more dangerous,we should give enough attention to this incident.Burning under well is studied with the method which combine with theory and actual phase.Use empirical formula to calculate for explosive limit of the combustible gas.Explosive limit data is determined with experiment method in order to make the data closer to the actual and it also provides data support for prevention of underground blasting accident.Control measures for burning explosion accident of air drilling under well are formulated combined with the actual situation based on the final conclusions.