This course covers the DFIT interpretation procedure from the paper URTeC-2019-123. The procedure was developed as part of a collaborative industry study sponsored by a group of six operators and one service company. It is the latest course offered by SAGA Wisdom,available to SAGA Wisdom subscribers.

Click here for more information on how to view the course.

Abstract

Diagnostic Fracture Injection Tests (DFITs) are used to estimate stress, pore pressure, and permeability. The term “DFIT” is often used broadly to refer to any injection/shut-in test designed to create a hydraulic fracture. However, it usually refers to a test performed in a low permeability formation (<10s of microdarcy), performed after the well has been drilled, and with intention performing an extended shut-in (one week is most common). this course covers dfit interpretation procedure from paper urtec-2019-123. was developed as part a collaborative industry study sponsored by group six operators one service company. starts stepping through basic physics - near-wellbore tortuosity, ideal nolte period, effect contacting fracture walls, late-time impulse period. we show how these behaviors can be diagnosed handful key plots. then, estimation stress, pore pressure, permeability. finally, concludes providing practical tips for interpretation. in formations permeability greater than 10s to 100s microdarcy, closure fundamentally different on shape pressure transient response lower permeabilities. focused dfits low (<10s microdarcy). urtec-2019-123 validated direct in-situ deformation measurements detailed numerical modeling matches field data, it derived analytically first-principles. compared 'holistic' procedure, gives somewhat higher estimates often much procedures differ other ways. example, they use equations 'frac efficiency' 'time closure.' discusses empirical theoretical reasons why yields more accurate parameter estimates.