Well testing of multiple high H₂S reservoirs in an environmentally sensitive area offshore Abu Dhabi

Abstract

Abu Dhabi Oil Co., Ltd. (Japan), ADOC, is currently operating three oil fields offshore Abu Dhabi; Mubarraz Field, Umm Al-Anbar (AR) Field and Neewat Al-Ghalan (GA) Field. In 2013, ADOC drilled, completed, tested and abandoned a well to appraise multiple sour reservoirs in a structure nearby to the existing three fields. The appraisal well was located in an environmentally sensitive area, so special measures were put in place to ensure the protection of the area during well testing operations. These measures included the re-injection of the produced hydrocarbon fluid and utilization of special burner booms to perform fallout-free combustion of liquid hydrocarbon. A tool designed by ADOC called the “Surface Testing Tool” was also utilized for safe operations of high H₂S fluids and to save rig time. This paper will summarize the various challenges, measures taken and lessons learnt during the well test in complex conditions and under stringent HSE regulations.