Innovations in Rig Rehabilitation: Improving Safety, Efficiency, and Life Cycle of Borewell Drilling Equipment

Abstract

Groundwater exploration in India requires robust and reliable drilling technologies to sustain increasing demand for water resources. The present study focuses on the rehabilitation and modernization of DTH/LMP-87/80 and DTH/RECP-88/92 drilling rigs operated by the Central Ground Water Board (CGWB), Division-IX, Hyderabad. The scope involved dismantling and remounting rigs on new truck chassis, structural reinforcements, and extensive hydraulic system upgradation covering pumps, motors, control valves, hoses, filtration, and cooling units. Assemblies such as mast systems, pull-down cylinders, hoisting arrangements, rotary drive heads, leveling jacks, water/foam injection systems, and drill rod handling mechanisms were either replaced or extensively refurbished. A structured inspection and quality control framework was followed at pre-assembly, post-assembly, and commissioning stages, with final acceptance based on trial drilling up to 200 m depth using the DTH method. The intervention extended rig service life by 15 years, improved drilling efficiency, enhanced operator safety, and ensured compliance with modern environmental and operational standards. This work demonstrates how systematic rig rehabilitation offers a sustainable, cost-effective alternative to new rig procurement, while strengthening India’s groundwater exploration capacity.

Introduction

Groundwater drilling is essential for India’s water supply for domestic and agricultural use. Many rigs operated by the Central Ground Water Board (CGWB) have exceeded their design life, leading to inefficiency, breakdowns, and safety risks. Given the high cost of new rigs, rehabilitating existing rigs offers a sustainable and cost-effective solution. This study documents the modernization of two CGWB rigs, focusing on hydraulic upgrades, structural refurbishments, and safety improvements, extending rig life by 15 years.

Key Aspects:

• Literature Gap: While rig modernization is well-studied in oil and gas industries, systematic rehabilitation of groundwater rigs in India has received limited attention.

• Methodology:

  • Dismantling old rigs and remounting on BS-VI compliant heavy-duty trucks.

  • Hydraulic, structural, and safety upgrades, including new mast assemblies, rotary drives, hydraulic pumps, automatic rod changers, and water/foam injection systems.

  • Comprehensive operator training and three-stage quality inspections.

• Technical Highlights:

  • Drilling capacity: 250 mm boreholes in overburden, 165/152 mm up to 200 m in hard rock.

  • Enhanced mast stability, rotary torque (570 kg-m), hoisting (13,000 kgf), and pull-down capacity (7,000 kgf).

  • New hydraulics with 650 L tank, filtration, and oil cooling; automatic rod handling; ergonomic control panels.

• Results:

  • Service life extended from 10 to 25 years.

  • Hoisting, pull-down, and rotary torque significantly improved.

  • Drilling cycle time reduced by 30%; operational costs halved.

  • Sustainability benefits via structural reuse and BS-VI compliant trucks.

• Project Management:

  • Milestone-based payment linked to delivery, commissioning, and training ensured quality and contractor accountability.

  • Liquidated damages clauses ensured timeliness.

Conclusion

The comparative analysis demonstrates that rehabilitation of DTH rigs delivers substantial improvements in technical performance, cost efficiency, and environmental sustainability. Service life was increased from 10 to 25 years, hoisting and pull down forces were significantly enhanced, and rotary torque was upgraded to 570 Kg-m. Cycle times were reduced by 30% and operational costs halved, making rehabilitation an economically attractive option compared to new rig procurement. By combining hydraulic system upgrades, safety enhancements, and automation, the refurbished rigs now operate at par with new equipment while ensuring operator safety and environmental compliance. The findings validate that rig rehabilitation is a sustainable and cost-effective strategy for groundwater development programs in India.

References

[1] Central Ground Water Board, Southern Region, Technical Report on Specifications for the Modernization of DTH Drilling Rigs. Hyderabad, India: CGWB-SR, 2023. [2] Bureau of Indian Standards, IS 10217:1982, \"Code of practice for design of hydraulic systems,\" New Delhi, India: BIS, 1982. [3] Bureau of Indian Standards, IS 9940:1981, \"Technical requirements for hydraulic cylinders,\" New Delhi, India: BIS, 1981. [4] M N, Chandan & Majumder, Himadri & Mulik, Sharad & Rangaswamy, Nikhil & Kumar, Mukesh & Srinivasaiah, Sowmyashree. (2025). Data?Driven Fault Diagnosis of Drilling Tools: Methods and Applications. Engineering Reports. 7. https://doi.org/10.1002/eng2.70279. [5] Kokkinis, A., Frantzis, T., Skordis, K., Nikolakopoulos, G., & Koustoumpardis, P. (2024). Review of Automated Operations in Drilling and Mining. Machines, 12(12), 845. https://doi.org/10.3390/machines12120845

Copyright

Copyright © 2025 Shubham Pal Singh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.