The effect of mercury contaminants in major gas developments

Abstract

Over the past ten years the region has witnessed the unforeseen presence of mercury during gas production which has affected projects not only in southeast Asia but more recently in Australian waters. This has caused major operational challenges and has often involved costly production impairment, loss of condensate sales value and major brownfield modifications. Today–s awareness of mercury has seen a new vigilance in well testing programmes intended to address the identification of mercury in gas streams during the early appraisal and concept development phases of an asset lifecycle. This paper looks at the ways in which operating companies have resolved the issue of unforeseen mercury production to date, and the operational experience and lessons learned. The paper describes some of the fundamental testing programmes as well as the available technologies for treatment and removal of mercury from production and effluent streams. It also identifies the impact of mercury on the design and operation of specific parts of the process as well as the overall impact on facility topsides. The impact of mercury on a development is shown to be manageable and least costly where identified and addressed during the conceptual stage of a project development. Technical, environmental, safety and regulatory issues associated with mercury can be tackled, minimising risk of production deferment, and the costs incurred can be quantified and incorporated into economic models.