Compounding Of Barium Sulfate Scale Dissolving Agent And The Efficiency Research

In order to solve the limitation of the single type of chelating scale dissolving agent in the process of dissolving scale,the distribution method was used in this article to enhance the dissolving efficiency of chelating scale dissolving agent.The compound of chelating agent and the annexing agent may make synergistic effects or modifying effects.Different kinds of additives were compounded based on one scale dissolving agent as the main agent,dissolving scale effect was promoted in many ways.First,a scale dissolving agent was selected out through the dissolving scale effect experiment and it is treated as the main agent.On the basis of the main agent,the solubilizer,the synergistic agent,the surfactant and scale inhibitors was selected in order.The scale dissolving result can be promoted through 4 main points:enhancing the solubility;improving the surface chemical property of the scale;promoting the activity of the reactions;improving solid-liquid interfacial tension.The recipe of the scale dissolving agent RG-17 is:the main agent,0.3mol/LDTPA;the solubilizer:10g/100mLNaOH;synergistic agent:oxalic acid 0.15mol/L + salicylic acid 0.05mol/L + Cinnamic acid 0.20mol/L + tartaric acid 0.10 mol/L;Surfactant:0.3mol/L;scale dissolving agent:8mg/LPESA.In this paper,the heat resistance and salt tolerant,the compatibility with a variety of formation water and injected water and the corrosion rate was evaluated.Experimental study was conducted on the influence of the content and the particle size of the scale,the reaction time and temperature and the salinity upon the BaSO4 scale dissolving result.The results show that:the scale dissolving efficiency increased with the increase of the density of the scale dissolving agent,the increase of the reaction temperature and time and the decrease of the content and the particle size of the scale.The scale dissolving efficiency has a slightly falling with the increase of the salinity.Based on the analyses of the formation water and injected water,combined with the scaling prediction software,the changing trends of the types and the amounts of the scales caused by different mixing ratios was analyzed.The result shows that the amount of barium sulfate is the biggest when the mixing ratio of the injected water and the formation water is 3 to 7,and the biggest amount is 1208.21mg/L.The mixing ratio 3 to 7 was selected for further research.Core flow tests was conducted by different concentration of RG-17.The result shows that the permeability is substantially improved and the concentration of the scale dissolving agent has some impacts on the scale dissolving result.Thus,the RG-17 has a good scale dissolving result to the reservoir.