Optimal Practices for Gas Injection to Overcome Black Powder Formation Utilizing Expert Systems

Abstract Gas injection systems are prone to black powder formation, hindering optimal reservoir injectivity and facility integrity. This paper presents best practices during the facilities design phase (FEL and FEED) to overcome these operational challenges by overseeing such systems, particularly in high gas injection systems. Expert systems workflow thoroughly analyzes potential black powder damages, including possible causes and recommendations to protect the injection facilities and reservoir formation to sustain long-term injection performance. A comprehensive expert system, including global field experiences and simulation studies, was developed to determine potential causes of forming black powder and recommend mitigating potential reservoir and facility damages. The analysis included the investigation of optimal dehydration for lean gas and the velocity to maintain inside the pipeline during reservoir injection. Moreover, optimal filtration systems and gas specifications were also investigated. The study indicates proper commissioning is the first step to ensuring that black powder is not formed in lean, rich gas pipeline sources. Other factors, such as long delays during construction and long pipeline exposure time, have increased the concentration of O2 and H2O (moisture) and the accumulation of corrosion solid contaminants inside the pipeline. The three primary root causes of black powder contamination are moisture (H2O), impurities (H2S, O2, CO2 or elemental sulfur), and operating condition (pressure or temperature variance). The paper lists several recommendations to overcome black powder formation, including adopting rigorous commissioning procedures, optimizing network design, regularly monitoring the injection gas quality (contaminant), and including corrosion management such as corrosion inhibitor injection and monitoring. In addition, scraping operation and corrosion monitoring can help mitigate the accumulation of Black powder.