Chemical Plugging Removal Technology and Discussion of Natural Gas Wells
As natural gas well scaling deposition causes wellbore blockage affecting the extraction effect, a new type of composite anti-scaling agent with low corrosivity and high scale inhibition performance was investigated. A series of comprehensive experimental studies such as scale characterization, brine composition analysis, fluid compatibility and stability, solubility test, precipitation dissolution equilibrium, corrosion test and core drive were carried out. The scaling samples included calcium carbonate and sulfate scales. The results showed that the dissolution rate of both samples was greater than 74％ after 6 h at 70 ℃, while both samples were completely dissolved after 5 h at 100 ℃. The pH value of the novel antiscalant was 9, and the low corrosion rate was 0.063 kg∙m-2 after 6 h at 6.9 MPa and 100 ℃. In addition, the core replacement test showed that the core permeability could be increased from the initial 0.67 mD to 1.29 mD by using the novel antiscalant, and that the novel antiscalant could significantly increase the core permeability and could be used for the chemical plugging removal of natural gas wells.
Chemical plugging removalAnti-scaling agentCharacterizationCore replacementNatural gasFouling
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