Induced micro-seismicity during well discharge: OW-719, Olkaria, Kenya rift

A micro-seismic survey was carried out in concurrence with reservoir interference tests around Olkaria well 719, which has a mass output of 140–160 ton/h. The correlation between output and micro-seismicity shows that the seismic intensity peaks have a time lag of 6 to 11 days behind the mass output...

Full description

Saved in:
Bibliographic Details
Published in:Geothermics 1999-12, Vol.28 (6), p.785-802
Main Author: Simiyu, Silas M
Format: Article
Language:English
Subjects:
Boreholes
Earth sciences
Earth, ocean, space
Earthquakes, seismology
Exact sciences and technology
Internal geophysics
Kenya
Kenya, Olkaria
Lithology
Mechanical permeability
Micro-seismicity
Olkaria
Seismic prospecting
Trace elements
Well discharge
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A micro-seismic survey was carried out in concurrence with reservoir interference tests around Olkaria well 719, which has a mass output of 140–160 ton/h. The correlation between output and micro-seismicity shows that the seismic intensity peaks have a time lag of 6 to 11 days behind the mass output peaks. Seismicity spreads from the well bore in two major directions, a faster NE–SW trend at about 0.6 m/h and a slow NW–SE trend at about 0.4 m/h. These rates are comparable to those obtained by injecting organic tracers and monitoring in adjacent wells. Fluid feeder zones are at 1300–1400 m and 1600–1800 m depth and are coincident with contacts between different lithologies that provide capping and horizontal permeability. A possible NNE–SSW trending barrier to fluid flow has been observed between OW-719 and OW-718 wells.
ISSN:0375-6505
1879-3576
DOI:10.1016/S0375-6505(99)00043-7