All exploration, drilling and production well objectives require drilling with or against Earth stresses. Plate vectors from GPS and SHmax vectors from earthquakes provide very limited predictive stress for the exploration and production industry. Wellbore measured stress data are sparse, post-drill and after the problem. SHmax magnitudes are modelled and their directions, being vectors, should not be averaged. The industry can have accurate 3D quantified Earth stresses, pre-drill and predictive generated from interpreted 2 or 3D interpreted reflection seismic surveys that companies have already paid for.
Stress consistent seismic interpretation and accurate fault histories can recognise fault sealed compartments at the prospect stage thus stemming the cost-waste and surprises created by ‘naughty rocks’ during the big-ticket appraisal and development drilling phases. Well designs can be simplified while risk is reduced, fractures emphasised, production maximised, fault plane collapse and sloughing hazards negotiated, sidetracks avoided, uneconomic fault sealed compartments identified, and often over-pressures mapped for EOHS protection. Lower oil prices are seeing sizable cuts to drilling programmes requiring fewer wells, longer well life and lower costs. Expensive wells are frequently the first to be cut, however, it is these very wells, that if most effectively stress planned, are often the key to higher flow rates and long-term cash flow.
Petroleum authorities would do well to encourage that all wells undergo this simple testing process as part of an integrated exploration and production approach to cost efficient and safer well design.
Presenter: John K Davidson
Mr John K. Davidson conducted Exxon’s 3-week, field-based, structural geology courses in western North America from 1974-75. Since 1983 he has conducted an annual field-based course in western England and Wales. The latter courses provided the link between structural geology and seismically recognisable, globally synchronous compressional pulses which can be used to predict present Earth stress. From 2000 the courses have evolved into a patented methodology and software programme for quantified stress predictions on fields and prospects in remote locations. In 2015 he sold the software to Stochastic Simulation Limited.