Hosted with thanks to our sponsor Spectrum
The 2016 Australian Stress Map: Implications for Petroleum Exploration and Production
by Dr Mark Tingay
Date & Time: Thursday 23rd March, 5.30pm (for talk start at 6.15pm)
PESA Members: $10.00 (Members must Log on to the PESA website to see the member prices)
PESA Students Members: Free (registration is essential)
Workshop Attendee: Free (you must register separately for each event)
Bookings close 12noon Thursday 23rd March 2017 for venue and catering purposes.
Knowledge of the present-day stress state is essential for petroleum geomechanics applications, such as the stability of boreholes; assessing fault reactivation and associated seal breach, and; improving production through natural and hydraulically-stimulated fractures. The present-day stress state of Australia has been compiled and mapped by numerous researchers over the past 25 years, and the latest version Australian Stress Map was officially released in December 2016. This represents the first major release of this public resource since 2008, with the Australian Stress Map now containing 2150 quality-controlled present-day stress records from 30 different geological provinces (more than double the data and regions in the previous release). The latest release of the Australian Stress Map represents a major improvement in our knowledge and understanding of stress and neotectonics of the Australian continent, and has important implications for a range of petroleum exploration and production issues.
The most striking aspect of the new Australian Stress Map is the major changes in regional stress orientations seen in some parts of the continent, as well as the observation of far greater stress complexity within many petroleum basins. In particular, the first analysis of stresses in many new basins reveals large discrepancies between observed stresses and those predicted by the dozens of previously published Australian stress models. This indicates that the controls on the stress field in Australia are much more complicated that previously considered, and that the present-day stress state is not solely a function of plate-boundary forces, as previously thought. The increased complexity of the Australian stress state, revealed by the Australian Stress Map, also highlights the relatively common occurrence of basin-, field- and wellbore-scale stress variations. The present-day stress is observed to change dramatically throughout many geological provinces, and sometimes, varies at the scale of just a few meters. Such localized stress variations have major implications for petroleum exploration and production, such as meaning that preferential deviation directions for stable production wells may vary from field to field, or even between drill centers. Furthermore, highly localized stress variations may result in complex hydraulic fracturing, with fracture propagation direction changing between fracture stages, and greater likelihood of tortuous and low-productivity fractures. The Australian Stress Map and underlying database is currently freely and publicly available via the World Stress Map Project, and can even be imported into Google Earth.