Additive Scale Removal Based on Noncorrosive Organic Acid for Handling Silica and Carbonate Scale in Oil and Gas and Geothermal Wells

Abstract

The silica and carbonate scale that forms along the production pipeline is a significant problem in the oil and gas and geothermal industry because it disrupts production operations. Silica and carbonate scales on the inside of the pipe cause blockage of flow and an increase in pressure. Failure of downhole settlement equipment will reduce the production capacity of the well, and the maintenance burden will increase. The main objective of this research is to test the reactivity of an environmentally friendly non-corrosive organic acid system based on vegetable fatty acids and carbohydrates with high dissolution efficiency for the treatment of silica and carbonate scales in geothermal and oil and gas fields. This paper provides information on laboratory analysis in terms of analysis of the composition of scale samples obtained through XRD analysis, acid system developed testing for dissolution efficiency at 50°C and 100°C for 1 hour, compatibility and stability testing, and testing the corrosive impact on coupon metal AISI CS-1019 samples at 100°C for seven days in a closed aging cell. Testing the concentration of the new organic acid system in high dissolution efficiency and low corrosion effect was carried out through laboratory-scale studies before being applied to field-scale operations. The results showed that the dissolution efficiency of the scale sample against the developed organic acid system (100% concentration) at 50 and 100°C for 1 hour showed reactive effect. Reduction rate of silicate-07; silicate-29; silicate-L1; silicate-KB1; carbonate-A3 at 50°C were 7.825%; 3.823%; 6.177%; 2.014%; 8.211%, and at 100°C were 12.884%; 0.631%; 15.047%; 0.103%; and 32.909%. The newly developed organic acid system demonstrates stability and compatibility with formation waters with low formed solids, and it has a pH of 6. The results of the corrosion rate test were carried out without an inhibitor at 100°C for seven days and gave a yield of 77.340 mils per year, while other commercial additives gave a yield of 2,525.120 mils per year. The new eco-friendly organic acid system has a good effect in helping dissolve silica and carbonate scales, safe for production equipment, and lowers high maintenance costs. Keywords: Organic Acid Scale Remover, Silica and Carbonate Scale, Environmentally friendly