Advanced Iron Sulfide Removal with Innovative Biosurfactant Solutions

Abstract Iron sulfide (FeSx) scale on production equipment can cause severe issues in the oil and gas industry, including formation damage, reduced production, pressure drops, and premature equipment failure. The formation of iron sulfide scale leads to corrosion and significant financial costs. Current methods, such as milling, jetting, acid soaking, and manual cleaning, are not viable options and can result in more downtime and pose severe safety or environmental risks. Due to their complex crystalline structures, iron sulfide scales are hard to dissolve. Operators employ a combination of prevention and management strategies, utilizing chemical and mechanical techniques tailored to the scale’s nature, location, and severity. This paper introduces a treatment using novel biosurfactants designed to effectively address the challenges of iron sulfide scales in oil and gas wellbores. A 5,078 ft MD bottom-hole agglomeration sample, composed mainly of silicates, calcium carbonate, iron sulfides, and iron oxides, from the West Texas San Andres Central Basin Platform was used to conduct a detailed study of several treatments using traditional inorganic HCl, several organic acids, and conventional additives, including our biosurfactant-mediated novel enhancer. The performance of these treatments, which focus on chemical/bio enhancements to acid treatment scales, has been assessed using methods such as acid digestion, filtration, FTIR spectroscopy, microscopy, and XRD. Laboratory tests indicate enhanced acid treatments with biosurfactants outperformed traditional FeS removal and dissolution additives. In some cases, these enhanced treatments achieved a reduction of more than 15% in sample weight, primarily due to the removal of scale from the contaminated bottom-hole sample. Microscopic images revealed noticeable degradation of iron mineral surfaces and disintegration of the iron species. Furthermore, FTIR and XRD analyses of the treated sample confirmed that biosurfactants effectively dissolved other mineral species, primarily targeting FeS minerals, and significantly reduced their concentration by up to 96%. Our groundbreaking biosurfactant formulation markedly enhances the efficiency of acidic iron sulfide scale removal compared to traditional industry additives. It highlights the innovative use of biosurfactants to significantly improve iron sulfide dissolution. This novel approach advocates for a transition to more sustainable and environmentally responsible practices within the industry.