Synthesis And Evaluation Of Water - Based Drilling Fluid Viscosity Reducer For Temperature - Resistant Polymer

In recent years, Chinese oil and gas exploration and development of the region continue to expand, gradually from shallow to deep, from simple to complex formation strata development, deep and ultra deep well will be the focus of future exploration and development. High temperature and high pressure have a great impact on the performance of drilling fluid, especially on rheology.We need to develop the anti-temperature and salt drilling fluid viscosity reducer, improve drilling performance deterioration caused by high temperature.In this paper, researched the high temperature viscosity reducer mechanism of viscosity and molecular structure design principles, to choose the temperature and salt resistant capacity of2-acrylamido-2-methyl propane sulfonic acid (AMPS) and has a strong hydration capacity with itaconic acid (IA), and adsorption with acrylamide (AM) monomer as the polymer, a polymer obtained by solution polymerization AAI reducing agent. Through single factor respectively monomer concentration, monomer ratio, reaction temperature, reaction time, pH, and increase the amount of initiator agents discussed, polymer viscosity reducer AAI to get the best conditions for the synthesis:AM, AMPS and IA in a molar ratio of1:2:2, adding ammonium persulfate initiator is selected as an amount of0.3%, copoly The reaction temperature is80℃,20%monomer concentration, reaction time4h, pH value of6. By IR, NMR molecular structure of synthetic products were characterized to determine the composition of the target product. By viscosity and gel chromatography analyzes thinner AAI relative molecular mass, determine its good thermal stability by thermogravimetric curve analysis. The viscosity reducer synthesized in freshwater base slurry viscosity reduction rate of up to94.5%.By thinner AAI performance evaluation, plus the amount of polymer viscosity reducer best AAI was0.3%; aging at different temperatures, have good viscosity reduction rate after200℃aging, the viscosity ratio64.9%, indicating that viscosity reducer AAI has good temperature resistance; in NaCl concentration of30%of the mud system can still maintain good viscosity reduction ability,viscosity reduction rate reached71.4%in normal temperature,160℃aging up to50.0%.1.0%calcium in the mud viscosity and has a good ability to decrease viscosity at room temperature was72.7%after160℃aging viscosity reduction rate was75.0%. This viscosity reducer have good performance at the resistance to temperature and salt, and better anti-calcium performance. Thinner products commonly used in different types of mud comparative study shows that viscosity reducer AAI has more superior performance. By particle size analysis, found that the drilling fluid viscosity reducer AAI enables the dispersion of fine particles increased, lowering the viscosity of the drilling fluid. Zeta potential was measured by the drilling fluid, was found after adding reducing agent, after high temperature aging or salinity of the drilling fluid, the drilling fluid system Zeta potential increase, drilling fluid viscosity decreases, rheology changed for the better, to improve the stability of drilling fluids.