Noel S Avocato

US Patent:

58652604, Feb 2, 1999

Filed:

Dec 18, 1996

Appl. No.:

8/750651

Inventors:

John R. Jackson - Houston TX
Noel S. Avocato - Austin TX
Alan Leiper - Aberdeen, GB6
Jan Wiersma - West Zann, NL

Assignee:

Chevron U.S.A. Inc. - San Francisco CA

International Classification:

E21B 712
E21B 704

US Classification:

175 5

Abstract:

A facility or platform (11) having a limited number of circular well-drilling slots (3) is converted to provide additional well-drilling locations on the platform (11) while protecting the platform (11) from the hoisting and lowering loads normally required to drill deep water wells. The additional well-drilling locations are provided by placing multiple wells in individual slots (3). Load protection is accomplished by transferring such loads to a underwater competent earth formation (15) with a thick-walled shroud (12). The shroud (12) surrounding the multiple wells carries at minimum by a plurality of internal centers through which the wells pass for assuring separation of the multiple wells and transmitting loads to the shroud (12).