Prediction of scale and corrosion in the oil and gas industry provides a valuable mean to address some of the most pressing challenges in field operations. Based on scale and corrosion tendency tests, a custom-built well integrity program can promote safer and more environmentally friendly production operations.

This paper presents practical techniques to predict potential scale and corrosion issues in a sour gas-producing field, and discusses control methods. The focus of this study is on the high pressure, high temperature deep horizontal wells that have been intensively acid fractured for economic production of tight gas. Scale precipitation is anticipated by geochemical analysis of produced water, including water hardness, limiting factor ion and stability index. Corrosion tendency is evaluated using laboratory tests simulating the acid fracturing treatment conditions.

Suspected scale and corrosion can be managed by applying a set of mitigating techniques, including selection and manufacturing of downhole completion equipment tubulars and accessories, acidizing treatment recipe and mixing guidelines, chemical inhibition selection and placement, as well as post-treatment over-flushing and flow back best practices. Innovative technological mitigating solutions include electro-kinetics technology, where more acid is consumed deeper inside the formation and a corrosion-sacrificial aluminum anode is incorporated. Also, the role of nano-sized additives in managing oxidizing reactions to enhance corrosion resistance is discussed. Field experiences have demonstrated that these strategies are effective in managing scale and corrosion, creating opportunities for asset reliability and operational excellence.

The novel technologies and operational guidelines discussed in this paper represent a holistic approach for operating companies to sustain tight gas production in spite of harsh scale-prone, corrosive operating conditions.

You can access this article if you purchase or spend a download.