East Texas 2005 |
Problem:
A vertical
exploration well in Harris County Texas was drilled to asses commercial
hydrocarbon potential of the Yegua and K1/Cochran sand packages. While
drilling 9-7/8” hole at a depth of 11,137 ft a kick was taken. While
circulating the kill mud the well started leaking at the Braden head flange.
The well blewout and caught fire shortly after. The well was initially
flowing gas, saltwater and sand to the surface from drillpipe and cellar.
Subsequent, the gas started broaching around the location both inside and
outside the levee area. After appearing to have bridged and then proceeding
to flow again several times, the fire went out and the well remained dead.
However, several potential underground crossflow scenarios still existed.
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Remedial Strategy: The initial plan selected was to first diagnose the potential underground crossflow scenarios prior to attempting control operations. The relief well would be drilled through the Vicksburg formation parallel and close proximity of the target well to check for crossflow into this formation. Subsequent, if no crossflow to the Vicksburg was identified, a temperature and noise log would be run to check for flow to shallower zones. Any flow would be hydraulically killed by injecting kill mud from the relief well into the blowout flowpath. After bringing the target well to static conditions, the blowout borehole and drillstring would be satisfactorily plugged and abandoned as required by the Texas Railroad Commission. Finally, as a secondary objective, the relief well would be drilled as a replacement well where it could reassess the commercial hydrocarbon potential. | |
Special Services: John Wright Company was contracted to provide both strategic and tactical special services. JWCO supervised the special services required for the relief well intervention project. This included pre-planning and on-site supervision of directional drilling, surveying, kill operations and casing detection. Vector Magnetics, responsible for electromagnetic ranging, was coordinated through JWCO on this project and worked together as one team. Well Flow Dynamics was instrumental in the diagnostic investigation and in simulating various kill scenarios for possible kill operations. Alert Disaster Control (US), Inc. acted as the general contractor. | |
Challenges Met: The project was complicated by the following:
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Results:
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