Inhibitor Squeeze Technique For Scale Control Of Oil Wells In W2 Jiangsu Oilfield

In the process of oil field development, particularly with increasing water production, scale has become a serious problem, which greatly affected oil production and transportation, resulting in high production cost and economic lose. This research aims at developing combined techniques to handle the scale and corrosion in oil producers, using scale inhibitor squeeze treatment in oil wells.The reasons and affecting factors of scale was analyzed, and the trend of scale was predicted using the softwares OFISTP3.0. The result showed that the calcium carbonate scale is serious under the formation condition of JiangSu Oilfield. The squeezing life of scale inhibitor is important to the squeeze treatment, which can be affected by the inhibitor and reservoir conditions. The adsorption of scale inhibitor in porous media influences the squeezing life greatly, as well as the squeezing operation parameters, and formation properties. In this study, different models for predicting the scale inhibitor squeezing life have been analyzed, and an improved squeeze empirical model based on laboratory data and field data has been derived, and computer software has been developed.In order to facilitate the application of inhibitor squeeze technique in JiangSu Oilfield, scale inhibitors have been selected based on laboratory experiments, including compatible tests, scale inhibition efficiency and MIC (minimum inhibitor concentration) experiments ,dynamic adsorption experiments and oil well core scaling control experiments. The effects of combined scale and corrosion inhibitors on scale were also studied. The results demonstrated that the combination of SA1320C and BUCT is satisfactory for scale and corrosion control.Finally, field operation procedures and scale inhibitors dosing techniques have been developed for oilfield application. Up to now, scale-inhibitor squeezing technique has been applied in two oil wells, and the result has been obtained. The efficiency of the scale inhibition techniques can be monitored by measuring the flow-back concentration of scale inhibitor in produced water, and through the inspection of oil tubes during workover operations.