Skip to Main content Skip to Navigation
Theses

Modélisation tridimensionnelle du comportement mécanique de la garniture de forage dans les puits à trajectoires complexes : application à la prédiction des frottements garniture-puits

Abstract : Drilling an oil well rapidly and at lower cost is now becoming a challenge in the drilling industry. To face and carry out this challenge, a good design of the drilling installation is essential. Therefore, predicting correctly friction losses, known as "Torque&Drag", between the drill string and the borehole is a major asset especially for directional wells with complex trajectories .
The existing models of friction calculation show some weaknesses in the case of complex trajectory wells. A new mechanical model of friction calculations inside complex trajectory wells was developed and validated. This model uses a 3D method of wellpath calculations called "Minimum of Torsion" that includes two geometric parameters: curvature and torsion. Unlike traditional models, which assume that the drilling structure lies, by gravity, on the low side of the borehole and often neglect the stiffness of the drill string, the new "Stiff String" model calculates the deformation state of the drilling assembly inside the hole via an iterative contact algorithm. Furthermore, the new model, by using a direct integration method of equilibrium equations, is much more faster than other one solved with finite element method.
A comparison with the widely used "Soft String" model was carried out on several actual and theoretical wells. The comparison shows that the new model rectify many weaknesses of the existing model such as the over-estimation of the contact zones and forces in the case of tortuous wells, the non sensitivity to the turn direction (left or right) in the case of 3D well paths, and the drillstring-wellbore contact assumption which is not usually verified.
Confrontations with measured data, in the case of wells having smooth trajectory (low tortuosity), show agreement of both models with field measurements. However the new model has better friction losses prediction when wellpath tortuosity increases.
Complete list of metadatas

https://pastel.archives-ouvertes.fr/pastel-00579916
Contributor : Bibliothèque Mines Paristech <>
Submitted on : Friday, March 25, 2011 - 1:43:12 PM
Last modification on : Wednesday, October 14, 2020 - 4:02:28 AM
Long-term archiving on: : Sunday, June 26, 2011 - 2:43:56 AM

Identifiers

  • HAL Id : pastel-00579916, version 1

Citation

Abdessalem Belaid. Modélisation tridimensionnelle du comportement mécanique de la garniture de forage dans les puits à trajectoires complexes : application à la prédiction des frottements garniture-puits. Géologie appliquée. École Nationale Supérieure des Mines de Paris, 2005. Français. ⟨NNT : 2005ENMP1323⟩. ⟨pastel-00579916⟩

Share

Metrics

Record views

1041

Files downloads

7149