Paper Title
A Comprehensive Review on Selection of Lost Circulation Materials for Fractured Oil Reservoirs

Abstract
The problem of lost circulation have for long time occurred during the drilling operation. The massive loss of drilling fluid can cause various drilling problems, thus increasing drilling non-productive time, cost and also leads to improper removal of cuttings out of the wellbore, which causes stuck pipe. Different solutions have been used to overcome this problem, these include chemical sealants, hydratable pills, rigid-plugs, gel polymer, cement and conventional LCMs. Type, shape, particle size distribution (PSD) and concentration are key parameters in determining the effectiveness of the lost circulation materials (LCM) and lost circulation pills (LCP). The method to combine these parameters in an optimized way leads to reducing or preventing the lost circulation effectively and protect the production zone from liquid and solids invasion significantly. The objective of this paper is to present different materials, their applications and limitations, and their optimized combination in controlling the mud lost circulation into oil fractured zones. Keyword - Lost Circulation Materials, Fractures Oil Reservoirs