30 C.F.R. § 250.1715   How must I permanently plug a well?


Title 30 - Mineral Resources


Title 30: Mineral Resources
PART 250—OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF
Subpart Q—Decommissioning Activities
Permanently Plugging Wells

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§ 250.1715   How must I permanently plug a well?

(a) You must permanently plug wells according to the table in this section. The District Manager may require additional well plugs as necessary.

                                      Permanent Well Plugging Requirements----------------------------------------------------------------------------------------------------------------                        If you have_                                          Then you must use_----------------------------------------------------------------------------------------------------------------(1) Zones in open hole......................................  Cement plug(s) set from at least 100 feet below                                                               the bottom to 100 feet above the top of oil, gas,                                                               and fresh-water zones to isolate fluids in the                                                               strata.(2) Open hole below casing..................................  (i) A cement plug, set by the displacement method,                                                               at least 100 feet above and below deepest casing                                                               shoe;                                                              (ii) A cement retainer with effective back-                                                               pressure control set 50 to 100 feet above the                                                               casing shoe, and a cement plug that extends at                                                               least 100 feet below the casing shoe and at least                                                               50 feet above the retainer; or                                                              (iii) A bridge plug set 50 feet to 100 feet above                                                               the shoe with 50 feet of cement on top of the                                                               bridge plug, for expected or known lost                                                               circulation conditions.(3) A perforated zone that is currently open and not          (i) A method to squeeze cement to all previously squeezed or isolated.                              perforations;                                                              (ii) A cement plug set by the displacement method,                                                               at least 100 feet above to 100 feet below the                                                               perforated interval, or down to a casing plug,                                                               whichever is less; or                                                              (iii) If the perforated zones are isolated from                                                               the hole below, you may use any of the plugs                                                               specified in paragraphs (a)(3)(iii)(A) through                                                               (E) of this section instead of those specified in                                                               paragraphs (a)(3)(i) and (a)(3)(ii) of this                                                               section.                                                              (A) A cement retainer with effective back-pressure                                                               control set 50 to 100 feet above the top of the                                                               perforated interval, and a cement plug that                                                               extends at least 100 feet below the bottom of the                                                               perforated interval with at least 50 feet of                                                               cement above the retainer;                                                              (B) A bridge plug set 50 to 100 feet above the top                                                               of the perforated interval and at least 50 feet                                                               of cement on top of the bridge plug;                                                              (C) A cement plug at least 200 feet in length, set                                                               by the displacement method, with the bottom of                                                               the plug no more than 100 feet above the                                                               perforated interval;                                                              (D) A through-tubing basket plug set no more than                                                               100 feet above the perforated interval with at                                                               least 50 feet of cement on top of the basket                                                               plug; or                                                              (E) A tubing plug set no more than 100 feet above                                                               the perforated interval topped with a sufficient                                                               volume of cement so as to extend at least 100                                                               feet above the uppermost packer in the wellbore                                                               and at least 300 feet of cement in the casing                                                               annulus immediately above the packer.(4) A casing stub where the stub end is within the casing...  (i) A cement plug set at least 100 feet above and                                                               below the stub end;                                                              (ii) A cement retainer or bridge plug set at least                                                               50 to 100 feet above the stub end with at least                                                               50 feet of cement on top of the retainer or                                                               bridge plug; or                                                              (iii) A cement plug at least 200 feet long with                                                               the bottom of the plug set no more than 100 feet                                                               above the stub end.(5) A casing stub where the stub end is below the casing....  A plug as specified in paragraph (a)(1) or (a)(2)                                                               of this section, as applicable.(6) An annular space that communicates with open hole and     A cement plug at least 200 feet long set in the extends to the mud line.                                      annular space. For a well completed above the                                                               ocean surface, you must pressure test each casing                                                               annulus to verify isolation.(7) A subsea well with unsealed annulus.....................  A cutter to sever the casing, and you must set a                                                               stub plug as specified in paragraphs (a)(4) and                                                               (a)(5) of this section.(8) A well with casing......................................  A cement surface plug at least 150 feet long set                                                               in the smallest casing that extends to the mud                                                               line with the top of the plug no more than 150                                                               feet below the mud line.(9) Fluid left in the hole..................................  A fluid in the intervals between the plugs that is                                                               dense enough to exert a hydrostatic pressure that                                                               is greater than the formation pressures in the                                                               intervals.(10) Permafrost areas.......................................  (i) A fluid to be left in the hole that has a                                                               freezing point below the temperature of the                                                               permafrost, and a treatment to inhibit corrosion;                                                               and                                                              (ii) Cement plugs designed to set before freezing                                                               and have a low heat of hydration.----------------------------------------------------------------------------------------------------------------

(b) You must test the first plug below the surface plug and all plugs in lost circulation areas that are in open hole. The plug must pass one of the following tests to verify plug integrity:

(1) A pipe weight of at least 15,000 pounds on the plug; or

(2) A pump pressure of at least 1,000 pounds per square inch. Ensure that the pressure does not drop more than 10 percent in 15 minutes. The District Manager may require you to tests other plug(s).

[67 FR 35406, May 17, 2002; 67 FR 44265, July 1, 2002; 67 FR 66048, Oct. 30, 2002]

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