Paper: Kris Ravi, B.R. Reddy and Mark Savery, Halliburton Energy Services, Mark Aston, BP

Losses while drilling is the one of the severe challenges faced by the well construction team. The area for improvement lies in a better understanding of how different products solve losses and which should be used under what condition. A fracture test device was built to study the effectiveness of different lost circulation materials such as gunk, calcium carbonate, graphite and mica. The variables investigated were the fracture size, lost circulation material type, concentration and size. In addition to the conventional lost circulation materials, different chemical systems were tested. Effect of oil based and water based drilling fluid was also investigated in this study. Results from the detailed investigation of the effectiveness of different materials to solve loss circulation challenge is discussed and presented in this paper. Based on the results, mechanisms by which different products solve losses and procedures to implement the solution are presented. The work can help in identifying the attributes of the lost circulation and applying the most appropriate solution.