Study On Fouling Mechanism And Anti-scaling Technology Of Wellbore In Water Injection Well Of G104 Block

International oil and gas industry is major facing scale control problems as fields mature. Based on the fluid analysis of G104 area in this paper, with the scaling theory inhibition tech-nology, the scaling mechanism and antiscale technology will be launched.Four injection wells of G104 area as the research object, scaling prediction software is a-pplied to study the regular pattern of variation of scaling type and quantity of injection wellb-ore under different conditions of temperature, pressure and pH value. Scaling and scaling fact-ors are carried out according to the prediction results. Result shows the major injection wellb-ore scaling is formed with calcium carbonate. Temperature and pH value are the main factors affecting the injection wellbore scaling with less effect of pressure.On the basis of major scaling types, antiscale technology study of injection wellbore will be launched. Result shows the most effective scale inhibitors for G94-8,G27-48,G80-26 and G78-56 injection wells wellbore scale are inhibitor DTPMPA,EDTMPS,GY-405 and GY-405 respectively. Every inhibitor has an optimum concentration value, shows that scale inhibitor evaluation research indicates with the increasing concentration of scale inhibitor, inhibition r-ate increases then decreases. With the increase of temperature, the inhibition rate increases first and then decreases. Pressure has little effect on the performance of 4 types of inhibitors. With the increase of pH value, the inhibition rate increases first and then decreases. The prim-ary and secondary sequence of the effect on the inhibition rate is pH value> temperature pre-ssure.Through the theoretical and experimental study we found that the calcium carbonate sca-ling induction period when adding scale inhibitors. With the increase of temperature, velocity and pH value, the calcium carbonate scaling induction period will be shortened.In order to reduce the production cost, improve the effect of scale inhibitor antiscaling, t-he study of scale inhibitor synergy effect will be launched. Result shows the GY-405 with T-H-607B has good synergistic effect, when the ratio of the inhibitor compound GY-405/TH-6-07B and GY-405/TH-607B/DTPMPA are 2:1 and 2:1:1 respectively, the antiscaling effect is best. The inhibition efficiency of compounds and single inhibitor behaved similarly under dif-ferent temperature, pressure and pH value influencing factors. Considering the production co-st, the injectin wells of G104 area should use inhibitor compounds which have a synergistic e-ffcct to improve the inhibition efficiency.