Study on Optimization of De-scaling Operations in Saudi Aramco Khuff Gas Wells

Khuff gas is considered the largest sour gas reservoir located in the Ghawar field in eastern province in Saudi Arabia. The main characteristics of Khuff gas reservoir are that H₂S, CO2 content as well as temperature varies significantly from the south to the north; the formation rock in Khuff gas reservoir comprises significant amount of carbonates.

Currently a number of Khuff gas wells have been experiencing serious scaling problem and the scaling problem become worse and worse. The de-scaling operations are the important way of solving the scaling problem in Khuff gas wells as the scale control in gas production systems of Khuff gas wells is very complex. In order to get effective chemical de-scaling results, the selections of chemical compositions of de-scaling fluids have to be based on the scale compositions. Though the Khuff gas wells are experiencing different types of scales, such as, iron compounds, calcium carbonate, barite / clay minerals and inorganic salts, the most common scales in the Khuff gas wells are mainly iron compounds (iron oxides and iron sulfides).

This paper explores several issues such as sources and mitigation of scale, the efficient de-scaling method in details.