High Content Of Hydrogen Sulfide, Carbon Dioxide Gas Field Drilling Supercritical Phase Transition To Safety, And Well Control

With the development of oil exploration and deep high temperature high pressure wells, the exploration condition comes more and more serious, especially for the sour-gad riched reservoirs, the well blowout, erosion, wax problem and scale problems take place more frequently. In the northeast of Sichuan, the H₂S riched gas reservoir is typical case,which the content of H₂S reach to 1%～13%, the most high content is 35.11 %. All the problems existed in this kind of reservoir bring too much matter to oil exploration and most of them caused by supercritical fluid. Under the situation, Based on the consideration above, it is necessary to introduce the supercritical fluid thesis to the oil exploration and do some researches on the phase of supercritical fluid. Therefore, the research will take great reference to the similar reservoirs, just like Luojiazhai gas field, Dukouhe gas field and Tieshanpo gas field, etc.After a lot of investigation and references, the phase equation was optimized with the analysis of existed fruits. The high pressure fluid viscosity calculation model was selected, and the relative parameters were calculated, such as Z-factor, density, viscosity and isothermal compressibility, etc. The research result brings forward that the supercritical CO₂ and H₂S takes great differences with normal gas. At the adjacent, the supercritical fluid's temperature and pressure with little change, the fluid density varied greatly. Applying SCF CO₂ to the abnormal formation pressure.Considering at the adjacent of critical point SCF CO₂ and H₂S have special characters,bring a new concept of SCF can lead to blowout.There are few researches on the supercritical fluid effect on the drilling and workover.when doing this paper there has a few informations of this aspects. Therefore, this paper start off the basic of phase and EOS, trying to find out the effect of SCF CO₂ and H₂S on the well control.Hereby, the contributions of this paper are development of the conception and proposition of SCF fluid which result in well control and introduction analysis and research.There have a distance between the fix quantify and practice application.The research on this field possess great theory and application. For the future, there need to launch into more force researches and draw a correspondence of measures which can instruct well control and control pressure.