Stress estimation using shear radial profiles: North Sea Case Study

by Adam Donald, Schlumberger

Abstract

Drilling, completions and field characterization all require input on the state of stress when planning operations. Stress models are traditionally generated using various models (poro-elastic from sonic, Mohr-Coulomb, mathematical models, etc.) but always require calibration from extended leak off and micro-hydraulic fracturing tests to constrain the least principle stress.

A new technique has been developed to estimate the maximum and minimum horizontal stress magnitudes using a combination of pore pressure, overburden stress and advanced full-waveform sonic data derived from the shear radial profiles. Knowledge of the wellbore stress state (axial, radial and tangential stresses) along with a non-linear elastic model is used to estimate the principle stress magnitudes. A case study from the North Sea will be discussed with applications to characterizing the stress state in weak overburden rocks.

Adam Donald, CV

Adam Donald is the Geomechanics Team Leader for the North Sea and has 11 years experience with Schlumberger. Adam joined Schlumberger Wireline in 1998 as a field engineer and worked throughout land and offshore Canada. In 2004 he moved to Denver, Colorado, USA where he was focused on tight gas evaluation in acoustics & petrophysics and applications to stress modeling and completion optimization. His current focus in the North Sea is wellbore stability, rock mechanics testing & completion optimization. He received his Bachelors in Geological Engineering from University of Waterloo in Ontario, Canada (1998) and a Masters in Mining Engineering from Dalhousie University in Nova Scotia, Canada (2004). Adam holds 2 Patents in areas of borehole acoustics and geomechanics. He is a registered Professional Engineer in the Province of Alberta, Canada and an active publishing member of SPWLA, SPE, and SEG.