Near real-time geomechanical modelling update and completion optimisation in the fold belt area of PNG: a case study with Oil Search Ltd*
Katharine Burgdorff A , David Castillo B , Adrian White C , Jon Rowse D , Gavin Douglas E and Mike Dow FA GeoMechanics International Perth WA. Email: KBurgdorff@geomi.com
B GeoMechanics International Perth, Western Australia. Email: dcastillo@geomi.com
C GeoMechanics International Perth, Western Australia. Email: awhite@geomi.com
D Oil Search Limited Sydney, New South Wales, Australia. Email: Jon.Rowse@oilsearch.com
E Oil Search Limited Sydney, New South Wales, Australia. Email: Gavin.Douglas@oilsearch.com
F Oil Search Limited Sydney, New South Wales, Australia. Email: Mike.Dow@oilsearch.com
The APPEA Journal 50(2) 725-725 https://doi.org/10.1071/AJ09089
Published: 2010
Abstract
Collecting high-resolution image data in the majority of currently-drilled wells in the Papuan Fold Belt area has substantially improved our knowledge of the subsurface. A major contribution comes from the observation that the contemporary stress field and the pore pressure environment in the fold belt area are non-uniform. Comprehensive analysis of high-quality LWD images through the overburden has combated uncertainties brought about by the heterogeneity in the stresses and pore pressure. These data have been especially important when updating or constraining a geomechanical model in near real-time for the purpose of providing wellbore stability and completion recommendations.
The geomechanical model unique to a particular part of the structure has been combined with finite-element modelling to help identify the optimal completion strategy for the reservoir sands in a number of wells. Recently, the near real-time geomechanical analysis has been used to quickly identify the optimal perforation direction in the reservoir in order to minimise the risk of solids production during completion. Essential data sources for the modelling include LWD images from the reservoir to confirm stress orientations and LWD density data and petrophysical analysis to accurately determine sand strength (UCS). A quick-look analysis uses the calculated UCS profile and the geomechanical model to identify, and therefore avoid perforating, any weak sections of the reservoir. Doing so hopefully mitigates the risk of solids production.
This paper outlines the workflow and displays some results from the Papuan Fold Belt area.
Keywords: geomechanical model, case study, high-resolution, image data, Papua New Guinea, LWD, near real-time, wellbore stability, solids production, completion, perforation orientation, rock strength, drilling
Katharine Burgdorff, Geomechanics Advisor. Katharine holds a degree in geology from Middlebury College and was part of a research team involved in coring in the Southern Ocean off Antarctica as well as in the North Atlantic. Katharine has been with GMI since 2002 and specialises in wellbore image analysis, fractured reservoir characterisation and wellbore stability, as well as GMI•Imager™ and GMI•MohrFracs™ software development. She has experience working in both the North America and Perth, Australia offices and she is now a Geomechanics Advisor for the Asia-Pacific region. |
David Castillo, PhD, Vice President and Chief Technical Advisor. David received his PhD in geophysics from Stanford University in 1993. David has worked with Amoco International, USGS, Lawrence Livermore National Laboratory, and the University of Adelaide. He is GMI’s most senior consultant responsible for identifying industry trends and clients’ needs related to all aspects of geomechanics and he helps drive the direction of applied research and development to expand the breadth and depth of geomechanics. David has extensive experience in geomechanical measurements and modelling with applications to field development, field review, reservoir characterisation, natural fracture characterisation, fault stability and fault leakage, EOR, completion strategies for maximising production efficiency, wellbore stability, managed pressure drilling, and CO2 sequestration feasibility. |
Adrian White, PhD, Geomechanics Adviser. Adrian received his PhD in structural and petroleum geology from the University of Durham in 2002. Between 2002 and 2004 he was a Postdoctoral Fellow at the Australian School of Petroleum, University of Adelaide. Since joining GMI in January 2005 he has been involved in training, consulting and project management in the Asia-Pacific region. Adrian has experience in constructing geomechanical models and pore pressure prediction from wireline log and seismic data. He has successfully implemented these processes in field and reservoir development and characterisation, fracture and fault stability, wellbore stability, drilling strategies and reservoir completion. Adrian currently has a role as a geomechanical technical adviser for the Asia-Pacific region. |
Jon Rowse, PhD, PNG Subsurface Manager. Jon received his PhD in geology from the University of Liverpool in 1988. He joined BP in 1988 and was involved in a variety of exploration, development and production roles in the North Sea, Australasia and the Gulf of Mexico. He joined Oil Search in 2003 and is currently the PNG Subsurface Manager, responsible for managing production performance, well interventions and new development opportunities across the PNG oil fields. |
Gavin Douglas, MSc, PNG Well Delivery Manager. Gavin received an MSc in reservoir evaluation and management from Heriot Watt University in 1997. He joined Schlumberger in 1998 and was involved in a number of green and brown field development projects in Australia and South East Asia. He joined Oil Search in 2003 and is responsible for delivering development well opportunities across the PNG oil fields. |
Mike Dow, BSc, Drilling Superintendent. Mike received his BSc in geology from the University of Aberdeen in 1985. He joined Baker Hughes INTEQ in 1986 and was involved in multiple drilling optimisation projects with oil companies worldwide. Mike joined Oil Search in 2003 and has been involved in planning and drilling a number of successful development and exploration wells in PNG and the Middle East. |
References
Brudy, M., and Zoback, M.D. (1993). Compressive and tensile failure of boreholes arbitrarily-inclined to principal stress axes: application to the KTB boreholes. International Journal of Rock Mechanics and Mining Science 30, 1035–8.Moos, D., and Zoback, M.D. (1990). Utilization of observations of well bore failure to constrain the orientation and magnitude of crustal stresses: Application to continental, Deep Sea Drilling Project and ocean drilling program boreholes. Journal of Geophysical Research 95, 9305–25.
Peska, P., and Zoback, M.D. (1995). Compressive and tensile failure of inclined well bores and determination of in situ stress and rock strength. Journal of Geophysical Research 100, 12791–811.
Streit, J., Van Der Zee, W., Burgdorff, K., Rowse, J., and Douglas, G., 2006—Near-Real-Time Wellbore Completion Strategies in Complex Tectonic Settings to Optimize Target Drilling and Completion. In: Proceedings from GEO ASIA 2006 Conference, Kuala Lumpur, Malaysia, 2006(3), 56–8.
Zoback, M.D., Moos, D., Mastin, L., and Anderson, R.N. (1985). Wellbore breakouts and in-situ stress. Journal of Geophysical Research 90, 5523–30.
