Advances in drilling technology enable oil & gas industry to drill faster and to minimize Non-Productive Time (NPT). This usually requires minimizing changes to the Bottom Hole Assembly (BHA) and improving its reliability. However, drilling systems are commonly subjected to dynamic dysfunctions, that can cause downhole tool failure, increase drilling cost and NPT, and compromise the wellbore quality. Therefore, understanding drilling dynamics behavior of BHA is a crucial step to improve drilling efficiency and to reduce NPT.

Recent advances in drilling and oil & gas extraction have altered the mindset among drilling engineers. One example is the recent trend to drill faster and minimize Non-Productive Time (NPT). This usually requires minimizing changes to the Bottom Hole Assembly (BHA) and improving its reliability. Directional drilling tools such as mud motors and Rotary Steerable Systems (RSS) have become a main stay in minimizing NPT.

Pere Andreu Ubach, Ferran Arrufat, Lev Ring, Raju Gandikota, Francisco Zárate, Eugenio Oñate, “Application of an enhanced discrete element method to oil and gas drilling processes”, Computational Particle Mechanics, October 2015, 10.1007/s40571-015-0080-5.

Eugenio Oñate, Francisco Zárate, Juan Miquel, Miquel Santasusana, Miguel Angel Celigueta, Ferran Arrufat, Raju Gandikota, Khaydar Valiullin, Lev Ring, A local constitutive model for the discrete element method. Application to geomaterials and concrete, Computational Particle Mechanics Journal, May 2015.

Vadim Tikhonov, Olga Bukashkina and Raju Gandikota, Stick-Slip Model for PDC Bits Accounting for Coupled Torsional and Axial Oscillations, ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis, Volume 2: Dynamics, Vibration and Control; Energy; Fluids Engineering; Micro and Nano Manufacturing, Copenhagen, Denmark, July 25–27, 2014.

Eugenio Oñate, Miquel Santasusana, Miguel A. Celigueta, Ferran Arrufat, Khaydar Valiullin & Raju Gandikota, A parallelized discrete element method for analysis of drill-bit mechanics problems in hard and soft soils, 11th World Congress on Computational Mechanics (WCCM XI). July 2014, Barcelona, Spain.

Miguel A. Celigueta, Salvador Latorre, Guillermo Casas, Eugenio Oñate, Raju Gandikota, Kedar M. Deshpande, A parallel FEM-DEM approach for analysis of cuttings transport in wellbores, 11th World Congress on Computational Mechanics (WCCM XI), July 2014, Barcelona, Spain.

Session chair at 11th World Congress on Computational Mechanics, Barcelona Spain. Moderating talk on “Advances in Modeling and Simulation of Drilling Operations” July 2014.

Jeremy S Daily, Lev Ring, Mehdi Hajianmaleki, Raju A Gandikota, Critical Buckling Load Assessment Of Drill Strings In Different Wellbores Using The Explicit Finite Element Method, SPE Offshore Europe Oil and Gas Conference and Exhibition, 3-6 September 2013, Aberdeen, UK.

Eugenio Oñate, Ferran Arrufat, Francisco Zárate, Pere A. Ubach, Raju Gandikota & Lev Ring, Advances In The Discrete Element Method For Drilling Mechanics Problems, 6th International Conference on Discrete Element Methods (DEM6), August 2013, Denver, Colorado USA.

Vadim Tikhonov, Khaydar Valiullin, Albert Nurgaleev, Lev Ring, Raju Gandikota, Pavel Chaguine, Curtis Cheatham, “Dynamic Model for Stiff String Torque and Drag”, 2013 SPE / IADC Drilling Conference and Exhibition, Mar 05 – 07, 2013 2013, Amsterdam, The Netherlands.

Mehdi Hajianmaleki, Jeremy S. Daily, The University of Tulsa, Lev Ring & Raju Gandikota, Weatherford, “Buckling Analysis of Drill Strings in Inclined Wellbores Using the Explicit Finite Element Method”, Proceedings of the ASME 2012 International Mechanical Engineering Congress & Exposition, IMECE2012, November 9-15, 2012, Houston, Texas.

M. Deshpande, D. Simpkins, R. Gandikota & L. Ring, SPE, Weatherford International, “Fracturing Completion System Optimization through Advanced Hydraulic Modeling”, SPE Russian Oil and Gas Exploration and Production Technical Conference and Exhibition, November 2012, Moscow, Russia.

Oñate, J.M. Carbonell , C. Labra , F. Zarate, F Arrufat , International Center for Numerical Methods in Engineering (CIMNE) & L. Ring , Raju Gandikota, Weatherford International Inc., “Modeling and simulation of a rotation drilling system with drag bits using coupled discrete and finite element methods”, 10th World Congress on Computational Mechanics (WCCM10), 9-13 July 2012, Sao Paolo , Brazil.

Nader Abedrabbo, Raju Gandikota & Lev Ring, Automation of Static and Dynamic FEA Analysis of Bottomhole Assemblies, 2012 SIMULIA Customer Conference, Rhode Island, USA, May 15-17, 2012.

Dmitry Pogorelov, Gennady Mikheev & Nikolay Lysikov, Lev Ring, Raju Gandikota & Nader Abedrabbo, A Multibody System Approach to Drill String Dynamics Modeling, The ASME 2012 11th Biennial Conference On Engineering Systems Design And Analysis (ESDA2012).

Richard DeLange, Raju Gandikota & Scott Osburn, A Major Advancement in Expandable Connection Performance, Enabling Reliable Gastight Expandable Connections, SPE Drilling & Completions Journal, Sept. 2011.

Martin Skrikerud and Raju Gandikota, Automatic Solutions for Hydroforming processes, Tube and Sheet Hydroforming Conference, Canada, 2006.

Lee, F., Murali, K., Heath, A., and Gandikota, R., “Simulation Based Development of Quick Plastic Forming,” SAE Technical Paper 2005-01-0088, 2005.

Teeparthi, S., Gandikota, V., Madhavan, V., Hooper, S. et al., “Multistage Sheet Metal Forming with Intermediate Annealing: Comparison of Finite Element Simulations with Experiments,” SAE Technical Paper 1999-01-1560, 1999.

Raju A. Gandikota, Incorporation of Intermediate Heat Treatments in Multiple Stage Sheet Metal Forming Simulations, 5th International LS-DYNA Users Conference, Southfield, Michigan, Sept. 21-21, 1998.

Viswanathan Madhavan, Raju A. Gandikota and Steven J. Hooper, Analysis of Multiple Stage Hydroforming of Sheet Metal With Intermediate Annealing, ASME Design Engineering Technical Conferences and Computers in Engineering Conference, Atlanta Georgia, Sept. 13-16, 1998.

The paper focuses on application of multibody system approach for the torque and drag analysis of long drill strings. The approach is used to get improved results as compared with those obtained by soft-string models. The analysis is carried out by integration of equations of motion of the drill strings till reaching equilibrium under externally applied loads corresponding to conditions of drilling operations.