Roma development drilling – evolution of well design and drilling performance

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.