Study on scaling mechanism and plugging removal technology of wellbore in Jingbian gas field

Abstract The scaling in tubing is a serious problem in Jingbian gas field, which leads to the increase of low production and low efficiency wells year by year. The production capacity of gas wells cannot be utilized effectively. In this paper, the scanning electron microscopy (SEM) was used to characterize the morphology of scale, and energy dispersion spectroscopy (EDS) and X-ray diffraction (XRD) were utilized to analyze the composition of scaling products. According to the design of the plugging removal scheme, the scale-dissolving test of acid plugging remover was carried out. The results show that the scale samples have a three-layer structure, and the morphology of the three layers is quite different, but the chemical composition of the three layers is CaCO3. After adding acid plugging removal agent, the scale-like reaction is severe, a lot of gas escape, 40 h completely dissolved, no solid residue. Based on the test results and the production situation of Jingbian gas field, the scaling mechanism of gas wells is clarified, and the plugging removal scheme is optimized, which provides a basis for increasing production and efficiency of Jingbian gas field.