Analysis of microseismic multiplets in a hydraulic fracturing operation
Abstract/Contents
- Abstract
- Development of shale gas and tight oil reservoirs is shaping the global energy outlook. The U.S. Energy Information Administration anticipates continued strong growth of these unconventional hydrocarbon sources both in absolute terms and relative to conventional sources. Given the tremendous scale of development over the coming decades, improving the tools available to optimize resource recovery is a high priority. This is particularly pronounced given low reported recovery factors, typically 3-7% for shale oil and 20-30% for shale gas. Developing an accurate physical model of the reservoir response to hydraulic fracturing is crucial for achieving improved recovery factors, but few tools are available to monitor the response of the reservoir to stimulation. Microseismic monitoring provides one of the few sources of spatiotemporal data during stimulation. This thesis begins with documentation of a methodology to identify groups of multiplets, seismic events that occur in essentially the same place with similar source characteristics, in microseismic data. Multiplets are useful in providing an improved understanding of microseismicity associated with the stimulation, as well as direct evidence of change in the reservoir. The workflow is presented for general application, then applied to a case study. This case study demonstrates the value of multiplets both for independently quantifying uncertainty and for directly observing changes in the reservoir. In this case, the uncertainty is much larger than estimated by the contractor who initially located the events, and changes in reservoir properties are significant. A discrete fracture network is inferred from the microseismicity associated with the hydraulic fracturing operation, and the resulting network's impact on production is analyzed. The inferred network is compared to the fracture network intersected by the wellbore, finding that many pre-existing fractures are not associated with detected microseismicity. In collaboration with Lawrence Livermore National Laboratory, a massively parallel hydraulic simulator is used to model hydraulic fracture propagation and the impact of stress shadows on parallel fractures. Finally, ambient seismic noise is used to extract noise correlation functions on an an unprecedentedly small spatial scale in in situ earth at the El Tatio Geyser. Apparent arrivals of multiple phases are identified in the raw noise correlation functions, an observation that has been made only after advanced processing in previous studies.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Hakso, Alex |
|---|---|
| Associated with | Stanford University, Department of Geophysics. |
| Primary advisor | Zoback, Mark D |
| Thesis advisor | Zoback, Mark D |
| Thesis advisor | Beroza, Gregory C. (Gregory Christian) |
| Thesis advisor | Mavko, Gary, 1949- |
| Advisor | Beroza, Gregory C. (Gregory Christian) |
| Advisor | Mavko, Gary, 1949- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Alex Hakso. |
|---|---|
| Note | Submitted to the Department of Geophysics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Alex William Hakso
- License
- This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).
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