Abstract
This paper presents the results of remote acidizing treatments performed in 7 injection wells of the Marlim Field, which is responsible for 35% of the Brazilian oil production. In recent years, solids and rust from the seawater injection process have severely reduced the injectivity of the wells. However, the high costs involved and the limited availability of dynamically positioned rigs required for conventional treatments have prevented the restoration of the injectivities and, consequently, the production of adjacent wells had to be restricted. The advent of remote operations using stimulation boats anchored to production platforms, whose application on a production well was described on a previous paper1 , provided a simple, efficient, and economical solution to the problem, since all treatments were operationally and economically successful, resulting in a total increase in the water injection rate of 6613 m3/d. In addition, the paper presents laboratory experiments that have been conducted to verify the influence of the acids (HF and HCl) upon the flexible flowline, wellhead equipment and the string's metals, which have shown that pumping acid remotely was safe. The technique developed can be applied to other deepwater offshore fields and ongoing research is being performed in other to extend it to different situations, such as production and/or gravel packed wells, where acid diversion plays a major role in the operation's success and spent acid may cause even more severe corrosion problems.
