This study presents the development of an innovative product which provides the combined functions of H2S sequestration and flow improvement in subsea applications. The product was applied and validated in an offshore field of Campos Basin for use via umbilicals in production wells.
The methodology is based on stabilization of the non-nitrogenated scavenger in the presence of solvents consisting of compounds with different ionicities. The efficiency of the combined product was demonstrated in relation to H2S abatement in the organic phase, as well as to flow improvement. Evaluations of elastomer compatibility, solvent loss, heat and cold stress testing, particle size and corrosivity of metallic materials qualified the product for umbilical injection. Field validation was performed in a production well that presented flow instability, high viscosity and high levels of produced H2S.
The combined product had a strong influence on water separation, promoted a good O/W interface formation, and showed high quality separated water, capacity to sequester H2S and reduce oil viscosity. In the approval phase for subsea application via umbilicals, the product achieved satisfactory results in all tests, satisfying internal specifications, and was considered suitable for this type of application. In the third and final stage, the product was tested in the field. The product application reduced the H2S level of the gas stream by approximately 90% and arrival pressure by over 20%, while well productivity increased by approximately 9%.
The results obtained at the laboratory scale for product development match its performance in the field. Accordingly, the laboratory techniques used were shown to reliably reproduce production conditions, which is extremely important in the development of more effective products.
