Synthesis And Performance Study Of APES/AA/AMPS As Oil Field Water Treatment Agent

Oil production has become an important industry which is related to the national economy with the increase of oil demand. The scaling problem in oil field is the main problem, such as barium, strontium and calcium scales. The national sustainable development strategy requires the development direction of water treatment agent is green and non-phosphorus, so it is necessary to develop a kind of non-phosphorus and multi-functional water treatment agent.Polyether monomer ammonium allylpolyethoxy sulphate(APES) was synthesized from eallyloxypolyethoxy ether (APEG) and amido-sulfonic acid at 120℃ with the presence of urea. The non-phosphoruswater treatment agentAPES/AA/AMPSwas synthesized by acrylic acid (AA), ammonium allylpolyethoxy sulphate(APES) and2-Acrylamide-2-methylpropanesulfonic acid (AMPS) with the solution of ammonium persulfate as an initiator. The structure and stabilizationof monomers and the synthesized polymer were characterized by Fourier transforminfrared (FT-IR), ’H-NMR analyzerand Thermogravimetric Analysis (TGA), which showed that the water treatment agent APES/AA/AMPS was synthesized successfully and had good thermal stability.The effects of monomer mass ratios, initiator, chain transfer agent, reaction temperature and reaction time on the performance of water treatment agent APES/AA/AMPS were alsoresearched.The properties of scale inhibition and dispersion of water treatment agent APES/AA/AMPS were studied by using the national standard test methods. The results showed that APES/AA/AMPS have excellent scale inhibition and dispersion performances. When the dosage of water treatment agent was 15mg/L, the efficiency against barium sulfate scale is 93.8%, and nearly 96.7% for strontium sulfate. The performance of APES/AA/AMPS on calcium carbonate was 84.4% at the dosage of 18mg/L and 100% for calcium sulfate at the dosage of 2mg/L.Besides, the water treatment agent has good comprehensive scale inhibition performance which average scale inhibition efficiency can reach 84.5% when the concentration is 10mg/L. When the concentration of APES/AA/AMPS was 4mg/L, the dispersion of iron oxide was excellent, and the transmittance was only 13.7%. The effect of the recycling water quality on the performances of the water treatment agent was also investigated.Then APES/AA/AMPS was compared with other commercial water treatment agents, which exhibitedit has obvious advantages.The morphology, crystal structure and crystal diffraction intensityof barium sulfate,strontium sulfate, calcium carbonate andcalcium sulfate scales were characterized by using scanning electron microscopy and X-ray powder diffraction. The results showed that the crystal morphologyof scales were changed obviously by using APES/AA/AMPS, but it only changed the crystal shape of calcium carbonate.It is concluded that the scale inhibition mechanism of the water treatment agent on barium sulfate, strontium sulfate and calcium sulfate is the adsorption, and the mechanism on calcium carbonate scale is the role of chelating and dispersion.