The heat and mass transfer characteristics of superheated steam coupled with non-condensing gases in horizontal wells with multi-point injection technique

A new fractal approach for describing induced-fracture porosity/permeability/ compressibility in stimulated unconventional reservoirs

Geothermal energy development by circulating CO2 in a U-shaped closed loop geothermal system

Performance of geothermal energy extraction in a horizontal well by using CO2 as the working fluid

Geothermal energy extraction in CO2 rich basin using abandoned horizontal wells

A numerical study on the non-isothermal flow characteristics of superheated steam in ground pipelines and vertical wellbores

World Drilling Limit Envelope: Why it Shows an Irregular Triangle?

What is the Optimal Operation to Eliminate Cuttings Bed by Using Jet Comminuting Technique

Drilling while Casing Extended-Reach Wells?What is the Limit?


 A dynamic model of drillstring under internal and external countercurrent-axial flows is presented, and the stability of drillstring under different drilling parameters is analyzed. Results are compared to previously published simplified models (e.g., fluid-free models, influx models, outflow models). The dynamic governing partial differential equation (PDE) of drillstring is established under internal and external countercurrent-axial flows by means of the differential element method. The equation taking into account the mechanical force, the fluid pressure, the buoyancy force, the inertial force, the gyroscopic force, and the Coriolis force. PDE equation can be converted into the ODE equations by using the Differential quadrature method (DQM) and combining the boundary conditions under different working situation of drillstring. The vibration response to submerged drillstring under different parameter αc, which represents the annular clearance, is studied by plotting the stability diagram. The results were compared with the reference model established by the former researcher. Two cases, cantilever beam model and hinged-hinged boundary conditions, were discussed and found that increases the value of αc that means the annular gap increases, the outflow velocity should be decreasing, thus the effect of fluid induced vibration would be decreasing. As for cantilever case, the stability region will change obviously with the change of parameter αc, but for Hinged-Hinged case, parameter αc has little influence on the stability region. The novelty of the new dynamic model of drillstring is lying in considering the internal and external countercurrent-axial flows effect for the first time. The numerical results can be implemented in drilling engineering to predict drillstring vibration and guide drillstring design.

How is the Dynamic of Drillstring Going Under Internal & External Countercurrent-Axial Flows?

He Li

Papers

A numerical study on the non-isothermal flow characteristics of superheated steam in ground pipelines and vertical wellbores

World Drilling Limit Envelope: Why it Shows an Irregular Triangle?

What is the Optimal Operation to Eliminate Cuttings Bed by Using Jet Comminuting Technique

Drilling while Casing Extended-Reach Wells?What is the Limit?

How is the Dynamic of Drillstring Going Under Internal & External Countercurrent-Axial Flows?