Deep Well Temperature Resistant Polymer Gel Packer Technology Research

When the safe density window of high temperature and high pressure (high sulfur gas wells) is very narrow, if we carry out well fluid non-circulation of downhole operation such as the lifting, the density of the drilling fluid is slightly higher, it is prone to leak, on the contrary gas in the formation would go into the wellbore and gradually move up. In this case, potential safey hazard exists in the presence of well kick and blowout accident. There is still no effective method for this condition at presentIn view of this problem, this paper puts forward a kind of polymer gel packing technology through literature survey and experimental research, which can effectively solve this problem, and has been in the site of initial test successful. In this paper, through the experimental study of the characteristics of a variety of polymer gel select special gel ZND as gel for this study. In the interior, the compatibility experiment of a special gel and drilling fluid is carried out; the experiment of improving the gel static shear complex; special gel breaking experiment and special gel temperature resistance experiment. Experiments show that the special gel is a kind of high viscosity, good shear thinning properties and thixotropy, resistance to dilute properties and heat resistance and salt tolerance and other properties of the material, and other aspects performance can meet the requirements of sealing technology. When the special gel system go into the borehole or formation, will produce more and more strong internal structure over time while it’s still, so as to achieve the purpose of sealing gas. When the underground construction is finished, the gel breaker can be first used for breaking, then the circulation of drilling fluid, so as not to damage the reservoir for the reservoir protection.In addition, the polymer gel sealing technology in field application are studied, after the polymer gel go into the bottom, will soon form a certain degree of gel slug in the shaft, which is of high viscosity, high charity shear, increased weigh, high starting of pressure difference, be able to completely separating strata of bottom of the wellbore and drilling fluid of upper wellbore, effectively sealing gas,slowly flowing velocity.In short, through the theoretical study of its feasibility, indoor research special gel properties as well as the site of several sealing test, the results show that a special gel sealing technology in dealing with high temperature and high pressure (high sulfur gas wells) is a feasible and effective method to solve well leakage and overflow, and provides a new train of thought and method.