Abstract Gas migration through cement columns has been a problem of the oil and gas industry for many years. The most problematic areas in Iranian South Pars Field operations for gas migration are in gas wells; which causes failure of about 30 % of the primary cement jobs. Gas migration in these gas wells occurs when drilling through the Kangan and Dalan formations. To control gas influx, cement densities required to successfully cement this zone could be as high as 120 pcf. Specially designed cements were used to “zone isolate” the high pressure coming from the formation. High density/low fluid loss cements were used in the past with limited success. The objective of this study was to develop an effective cement formulation to control deep gas migration during primary cementing. To measure major slurry properties lab equipments were utilized for this study. A static gel strength analyzer (SGSA) is used to determine the static gel strength of formulated well cements to confirm the data from previous experiments on the slurry (rheology, filtration, and free water). Results from the SGSA were utilized to reduce the gas migration problem. This study also discusses the individual components necessary for gas-leak elimination. In addition, clearly addresses the gas migration problems related to cementing operations.
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