Khuff gas reservoir is considered the largest sour gas reservoir located in the Ghawar field in the
Eastern Province in Saudi Arabia. Currently a number of Khuff gas wells have been experiencing
scaling problems. The scale compositions have been analyzed, and the scale composition analysis results
show that the most common scales in the Khuff gas wells are iron compounds (iron oxides / hydroxides
and iron sulfides) and calcium carbonate. The scale sources of the iron compounds and calcium
carbonates in Khuff gas wells have been expounded in detail through theoretical mechanism analyses.
Based on the reaction mechanisms between the scales and the chemical de-scaling fluids, the optimal
chemical de-scaling methods and procedures in Khuff gas wells are developed.