Safe Execution of Sour Well Tests in the Kidan Field

Abstract

Executive Summary The South Rub Al-Khali Company Limited (SRAK) is an incorporated Joint Venture between Shell Saudi Ventures Limited (50% share) and Saudi Arabian Oil Company (50% share) to explore for non-associated gas and associated liquids in the South Rub’Al-Khali Basin (Empty Quarter) in the Kingdom of Saudi Arabia. This paper describes the key HSE processes which were an integral part of the SRAK management system employed to achieve the safe execution of critical sour gas well tests. SRAK has to date drilled two extremely sour, multiple reservoir wells. During the drilling phase, the H2S gas is kept – by design – down hole in order to minimize any exposure to personnel. However, during the production test phase the production of gas from these sour wells carries one of the highest risk factors in the oil industry. It requires meticulous planning and execution with strict adherence to established plans and procedures. Extensive training and competence assurance is required before allowing highly toxic gasses to flow to surface. These well tests have put the Kidan field onto the map as a potential commercial development, in spite of the high cost of remote desert area operations combined with the inherent complexity of the sour gas contained in the Kidan structures. This paper will describe the numerous safety challenges involved in the testing of two highly sour wells, SRAK-A and SRAK-B. It also outlines the approach that was followed to ensure safety in design, execution and emergency response planning. Case histories will explain the effective handling of unplanned H2S gas release events on surface will be used to demonstrate the effectiveness of training and systems in place. Learning, and associated introduced improvements, will be described as part of an operational efficiency review.