Ion Ispas, Ph.D.
Associate Professor, George P. Livermore Chair
Petroleum Engineering Dept.,
Texas Tech University
This work presents the results of an integrated laboratory and numerical modelling study on the effect of wellbore deviation and wellbore azimuth on fracture propagation in poorly consolidated sandstone formations. The goal of this project was to develop an understanding of how fractures would transition from single planar fractures to non-planar transverse fractures for fields in the deep-water Gulf of Mexico. The foundation of this work was over 40 fracturing laboratory tests to measure fracture propagation geometries for a range of well deviations, differential horizontal stresses and rock strength.
The laboratory results were used to develop and calibrate a new fully-3D finite element model that predicts non-planar fracture growth. The model matches the details of the laboratory tests, including the transition from planar vertical to non-planar transverse fractures as the well deviation, azimuth and stress differentials increase and successfully predicted the transverse non-planar results found in the laboratory; this gave us increased confidence in the model as a predictive tool. This work has been applied with excellent success to deepwater fields. We have recommended changes in maximum well deviations, performed post-job analyses on wells that had high deviations, and have increased our understanding of the impact of layered formations on fracture growth in these fields.
Dr. Ispas holds a Ph.D. in Petroleum Engineering from the University of Oklahoma (1999). His oil industry experience includes field operations, research, and management in petroleum engineering, geomechanics and chemical engineering with Amoco, British Petroleum, Conoco Phillips, Crystaltek, Schela Productie Gaze Naturale (SPGN) and teaching at the University of Oklahoma, British Petroleum – Chevron Training Alliance, and SPGN. He served in various capacities, including senior research engineer, research and development program manager, rock mechanics and hydraulic fracturing lab manager, geomechanics and hydraulic fracturing technical advisor, and, most recently, rock mechanics fellow.
Currently he is an Associate Professor, George P. Livermore Chair, Bob L. Herd Petroleum Engineering Department, Texas Tech University. Research interests: geomechanics, specialized lab testing for reservoir characterization, fluid-rock interaction, well completions and sand control, stimulation (hydraulic fracturing & acidizing), and production optimization.