The table in this section identifies specific design, setting, and cementing requirements for casing strings and liners. For the purposes of subpart D, the casing strings in order of normal installation are as follows: drive or structural, conductor, surface, intermediate, and production casings (including liners). The District Manager may approve or prescribe other casing and cementing requirements where appropriate. ------------------------------------------------------------------------
Cementing
(a) Drive or Structural..... Set by driving, If you drilled a
jetting, or portion of this
drilling to the hole, you must use
minimum depth as enough cement to
approved or fill the annular
prescribed by the space back to the
District Manager. mudline.(b) Conductor............... Design casing and Use enough cement to
select setting fill the calculated
depths based on annular space back
relevant to the mudline.
engineering and Verify annular fill
geologic factors. by observing cement
These factors returns. If you
include the cannot observe
presence or absence cement returns, use
of hydrocarbons, additional cement
potential hazards, to ensure fill-back
and water depths; to the mudline.
Set casing For drilling on an
immediately before artificial island
drilling into or when using a
formations known to well cellar, you
contain oil or gas. must discuss the
If you encounter cement fill level
oil or gas or with the District
unexpected Manager.
formation pressure
before the planned
casing point, you
must set casing
immediately.(c) Surface................. Design casing and Use enough cement to
select setting fill the calculated
depths based on annular space to at
relevant least 200 feet
engineering and inside the
geologic factors. conductor casing.
These factors When geologic
include the conditions such as
presence or absence near-surface
of hydrocarbons, fractures and
potential hazards, faulting exist, you
and water depths. must use enough
cement to fill the
calculated annular
space to the
mudline.(d) Intermediate............ Design casing and Use enough cement to
select setting cover and isolate
depth based on all hydrocarbon-
anticipated or bearing zones and
encountered isolate abnormal
geologic pressure intervals
characteristics or from normal
wellbore conditions. pressure intervals
in the well.
As a minimum, you
must cement the
annular space 500
feet above the
casing shoe and 500
feet above each
zone to be
isolated.(e) Production.............. Design casing and Use enough cement to
select setting cover or isolate
depth based on all hydrocarbon-
anticipated or bearing zones above
encountered the shoe.
geologic As a minimum, you
characteristics or must cement the
wellbore conditions. annular space at
least 500 feet
above the casing
shoe and 500 feet
above the uppermost
hydrocarbon-bearing
zone.(f) Liners.................. If you use a liner Same as cementing
as conductor or requirements for
surface casing, you specific casing
must set the top of types. For example,
the liner at least a liner used as
200 feet above the intermediate casing
previous casing/ must be cemented
liner shoe. according to the
If you use a liner cementing
as an intermediate requirements for
string below a intermediate
surface string or casing.
production casing
below an
intermediate
string, you must
set the top of the
liner at least 100
feet above the
previous casing
shoe.------------------------------------------------------------------------