Research On The Mechanics Of Anti-Fluid-Channeling And Lost Circulation Prevention

In order to solve the contradiction of pressure stability and the leak proof in complexformation cementing.We study the mechanical conditions and mechanism of circulation lossand the formation fluid invasion in complex formation in some blocks of Daqingoilifeld.Mechanics method of anti-fluid-channeling and lost circulation prevention and stressconditions of safety cementing have been explored.A basis be provided to improve cementingquality and the safety of cementing.This papper systematically analyzes the leakage and instability on the basis of fullinvestigation and analysis of the actual drilling and cementing engineering constructionmaterials.Leakage type discriminant method and the mechanical condition of leakage andfluid channeling are put forward.The dynamics and statics of cement slurry are analysed.Thecalculation model of slurry lfow pressure and slurry weightlessness are established.Theconcept of safety window of narrow pressure and a new calculation and analysis method ofleakage depth and pressure are put forward.The calculation of pressure window and pressurevalue of speciifc block are determined.The influence of slurry performance parameters isanalyzed.A cementing slurry system are chose for a given block.The design formula andselection method of cement construction parameter are put forward.