Page 48 - ASME DSCC 2015 Program

Technical Program

Control of Rotary Steerabe Toolface in Directional Drilling Modeling and Control of Coupled Torsional and lateral Vibrations in
Contributed regular paper. DSCC2015-9857 Drill Strings
Madhu Vadali, yuzhen xue, Halliburton, Houston, TX, United States, Contributed regular paper. DSCC2015-9714
xingyong Song, Halliburton Energy Service Co, Houston, TX, United States, liu Hong, Jaspreet Dhupia, Nanyang Technological University, Singapore,
Jason Dykstra, Halliburton Energy Services, Spring, TX, United States Singapore
This paper presents a detailed mathematical model of a rotary steerable Excessive vibrations of the drill-strings, e.g., the stick-slip vibration, are the
drilling system (RSS) that adopts hydro-electromechanical devices to gener- primary cause of premature failures and drilling inefficiencies in oil-well
ate bending torque in adjusting the toolface (TF). Key requirements of RSS drilling. To investigate and suppress such vibrations, this paper studies
are to adjust the TF promptly to track the TF command, to maintain the TF the dynamics of drill-strings using a high fidelity model, in which both the
in presence of the external disturbances, and to do so during the drilling torsional stick-slip and lateral vibrations are taken into consideration. The
process. Accordingly, a controller with a fast response time and effective friction torque due to the down-hole bit-rock interaction, which plays a key
disturbance rejection capability is desired for the RSS. The complexity and role in stick-slip vibration, is modeled as a hysteretic dry friction function.
non-linearities of the RSS creates additional challenges to the controller Simulated results of this developed model are shown to have a close quali-
design. This paper describes a simple and effective controller scheme that tative agreement with the field observations in terms of stick-slip vibrations.
is designed based on the analysis of the system’s dynamics model. By Afterwards, a sliding mode controller is applied to mitigate the undesired
decoupling the disturbances, physical state feedback, and non-linearities, vibrations of drill-strings. A good control performance in suppressing the
the RSS can be controlled by using a simple and effective proportional-inte- stick-slip phenomenon is demonstrated for the proposed controller. Howev-
gral-derivative (PID) controller with the desired performance. The simulation er, numerical simulations also demonstrate that the control action can excite
results show that the proposed controller is effective against the disturbance lateral instability in the system, which can result in impacts between the drill
and the variations of the parameters. collars and the borehole wall due to the large amplitude in lateral vibrations.
Modeling and Control of Automated Pipe Hoisting in oil and Gas Well Thus, a proper choice of the control parameters is essential to suppress the
Construction vibrations in the drill-strings. The high fidelity model describing the coupled
Invited session paper. DSCC2015-9936 torsional and lateral response in controlled drill-string presented in this
paper can be used to aid in offline tuning of the control variables.
Parham Pournazari, Pradeepkumar Ashok, Eric van oort, University of
Texas at Austin, Austin, TX, United States Drillbotics International Drilling Competition: Students Automating the
Drilling Process
Modeling and Control of Automated Pipe Hoisting in Oil and Gas Well Con-
Invited session paper. DSCC2015-9951
struction
Mitch Pryor, Dongmei Chen, The University of Texas at Austin, Austin, TX,
Modeling of Coupled Axial and Torsional Motions of a Drilling System
United States
Invited session paper. DSCC2015-9939
Drillbotics International Drilling Competition: Students Automating the
Zheren Ma, Dongmei Chen, The University of Texas at Austin, Austin, TX, Drilling Process
United States
During drilling operations, rock-bit interactions may cause a wide range of ConTRIBuTED SESSIon
1-23-1 TM1 Motion and Vibration Control Applications
undesirable system vibrations. The induced vibrations subsequently reduce
George Bellows A 1:30pm–3:30pm
drilling efficiency and increase fatigue loads acting on drill bit. In this paper,
a coupled torsional and axial drilling model is proposed. It can be used to
predict the vibrations including bit bounce and stick-slip. Instead of using Session Chair: Cong Wang, New Jersey Institute of Technology
finite element (FEM) approach, the drill pipe is accurately modeled based Session Co-Chair: Wenjie Chen, University of California Berkeley
on wave propagation theory. This results in time-delay equations in time Enhanced Motion Control of Powertrain using a Combination of Active
domain and significantly reduces the computational complexity associated and Passive Mounts
with FEM. The axial and torsional motions are coupled by bit-rock interac-
Contributed regular paper. DSCC2015-9622
tions. Different rock-bit interaction conditions are considered based on bit
rotation and contact with formation. Simulations are conducted using the Jared liette, Rajendra Singh, The Ohio State University, Columbus, OH,
United States
proposed model to analyze the impact of different applied weights on bit
and surface rotary speeds on the system vibrations. This information pro- Vibration control of a realistic coupled powertrain and frame system is ana-
vides insights into optimization of drilling operation. lytically and computationally studied using a combination of active and pas-
sive mounts. Actuators are placed in the powertrain paths for active control,
and passive mounts are employed such that the powertrain roll motion is
dominant using the torque roll axis motion decoupling concept. To facilitate
this study, a new 24 degree of freedom mathematical model for a coupled
powertrain and frame is developed with versatility where passive only, active
only, or combined active and passive powertrain paths can be selected.
Active control forces are defined as constant, real valued amplitudes to
48 counteract the dominate powertrain roll motion. Alternate path models are
then quantitatively compared based on the global powertrain motion mag-