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Full-Text Articles in Engineering
Numerical And Field Data Analysis Of Drill Stem Vibration, Mohammed Fayez Al Dushaishi
Numerical And Field Data Analysis Of Drill Stem Vibration, Mohammed Fayez Al Dushaishi
Doctoral Dissertations
"Drill stem vibration is a major cause of premature failure of drill stem components and drilling inefficiency. In severe cases, drill stem vibration may lead to wellbore instability that could lead to increased operational cost. Drill stem vibrations are affected by design decisions and the drilling environment. Examples are; bottom hole assembly configurations, selection of operational parameters, and frequent changes in lithology. Vibration modeling, analysis of vibration data, and specialized vibration reduction tools are methods in use to prevent and mitigate severe vibrations.
A drill stem vibration model was created using nonlinear strain formulation which couples the axial, lateral and …
Investigation Of Lost Circulation Materials Impact On Fracture Gradient, Mortadha Turki Alsaba
Investigation Of Lost Circulation Materials Impact On Fracture Gradient, Mortadha Turki Alsaba
Doctoral Dissertations
"Lost circulation is a challenging problem to be prevented or mitigated during drilling. Lost circulation treatments are widely applied to mitigate losses using a corrective approach or to prevent losses using preventive approaches, also known as "wellbore strengthening". The disagreement among the different wellbore strengthening theories and the lack of understanding the strengthening mechanism resulted in the absence of a standardized method to evaluate the effectiveness of lost circulation materials (LCM) for wellbore strengthening application.
An extensive experimental investigation was performed by constructing a high pressure LCM test apparatus to investigate the effects of different parameters on the sealing efficiency …