Tiltmeter data inversion with continuous, non-uniform opening distributions: A new method for detecting hydraulic fracture geometry

Abstract

Abstract Tiltmeter technology has long been an important fracture diagnostic tool. Tiltmeters are extremely good at determining fracture azimuth and dip. However, details about fracture opening variations have not been exploited in the past, partly because of a lack of data resolution to justify more work. The work presented here extends tiltmeter inversion modeling by solving for a non-uniform fracture opening distribution (fracture opening can vary with height and length). This more detailed fracture geometry can give clues to fracture growth processes such as asymmetric wing development and multi-zone fracture propagation. Theoretical calculations show the type of fracture geometry variation that can be imaged, and the technique is demonstrated interpreting field data from a shallow reservoir in California. The motivation for extending tiltmeter analysis methods is to take advantage of newly developed field instruments that can be installed at greater depth to image fractures to as deep as 10,000 ft.