Roma development drilling – evolution of well design and drilling performance
Andrew Sellars A B , Thivanka Dedigama A and Mohammad Zaman AA Santos Ltd, 32 Turbot Street, Brisbane, Qld 4000, Australia.
B Corresponding author. Email: andrew.sellars@santos.com
The APPEA Journal 59(2) 814-818 https://doi.org/10.1071/AJ18254
Accepted: 28 March 2019 Published: 17 June 2019
Abstract
Santos’ Roma field, located in the Surat Basin, has been producing coal seam gas (CSG) since 1988; however, development drilling did not commence until 2011. Since this time, well design has evolved to maximise access to coals and operability for artificial lift systems. Concurrently, performance has dramatically improved through scale of sanctioned work programs and revised contracting strategies, enabling continuous and sustainable time and cost reductions. This paper reviews Santos’ development drilling activity in the Roma CSG field since 2011, highlighting critical events and step changes.
The following aspects are addressed:
• Evolution of well design: A series of well designs have been trialled, ranging from deviated to vertical, fracture stimulated to open-hole slotted liner well types. Collaboration with both Reservoir Engineering and Production Operations have been critical in arriving at a fit-for-purpose design.
• Effect of the industry downturn: The industry downturn spanning 2014–2016 presented an opportunity to reset and rationalise execution approach.
• Operating and contracting model: The updated model focused on utilising a consistent, fit-for-purpose rig fleet and service companies, supported by lean office and field based operations teams.
• Benefits of large scale, continuous work programs: The scale and continuity of operations are key to achieving continuous and sustainable time and cost reductions.
• Opportunities: Future opportunities have been identified for ongoing optimisation in a changing market.
Keywords: coal, coil, continuous, contracting, cost, deviated, downturn, gas, lean, limit, liner, opportunities, Queensland, saving, scale, seam, slotted, stimulated, strategy, Surat, sustainable, technical, time, vertical.
Andrew Sellars has a Bachelor of Commerce and is the Onshore Drilling and Completions Performance Lead at Santos Ltd. He is responsible for leading, implementing and delivering consistent and transparent performance management across onshore Australia. Prior to joining Santos Ltd in 2013, Andrew held a corporate tax position with Deloitte. He is a chartered accountant and member of Chartered Accountants Australia and New Zealand. |
Thivanka Dedigama has a Bachelor of Engineering Science and a Master of Engineering Science, and is the Team Leader CSG Drilling and Completions at Santos Ltd. He is responsible for technical well designs, assurance and cost management for well construction and well servicing activities in Queensland. Thivanka has 14 years of oil and gas experience including 9 years in drilling and completions roles across the Queensland CSG, Cooper Basin and offshore operations in Vietnam and Bangladesh. He is a chartered professional member of Engineers Australia, a registered professional engineer of Queensland and a member of the Society of Petroleum Engineers. |
Mohammad Zaman has a Bachelor in Chemical Engineering and is a Senior Drilling Engineer in the CSG Drilling and Completions department at Santos Ltd. He has over 10 years of experience in drilling and completions across Queensland CSG and Vietnam offshore. Mohammad leads a team of engineers delivering the planning and execution of CSG well construction. He is a chartered professional member of Engineers Australia, a registered professional engineer of Queensland and a member of the Society of Petroleum Engineers. |
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