Author/Authors :
Velayati، Arian نويسنده School of Mining, Petroleum and Geophysics Engineering; University of Shahrood, Iran Velayati, Arian , Kazemzadeh، Ezatallah نويسنده 1 Research Institute of Petroleum Industry (RIPI) , , Soltanian-Zadeh، Hamid نويسنده , , Tokhmechi، Behzad نويسنده School of Mining, Petroleum and Geophysics Engineering, Shahrood University of Technology, P.O. Box 316, Shahrood, I.R. Iran ,
Abstract :
Cementing is an essential part of every drilling operation. Protection of the wellbore from formation
fluid invasion is one of the primary tasks of a cement job. Failure in this task results in catastrophic
events, such as blow outs. Hence, in order to save the well and avoid risky and operationally difficult
remedial cementing, slurry must be optimized to be resistant against gas migration phenomenon. In
this paper, performances of the conventional slurries facing gas invasion were reviewed and compared
with modified slurry containing special gas migration additive by using fluid migration analyzer
device. The results of this study reveal the importance of proper additive utilization in slurry
formulations. The rate of gas flow through the slurry in neat cement is very high; by using different
types of additives, we observe obvious changes in the performance of the cement system. The rate of
gas flow in neat class H cement was reported as 36000 ml/hr while the optimized cement formulation
with anti-gas migration and thixotropic agents showed a gas flow rate of13.8 ml/hr.
