Section 250.829 - Subsurface safety devices in shut-in wells-subsea trees(a) You must equip all new subsea tree completions (perforated but not placed on production) and completions shut-in for a period of 6 months with one of the following: (1) A pump-through-type tubing plug;(2) An injection valve capable of preventing backflow; or(3) A surface-controlled SSSV, provided the surface control has been rendered inoperative. For purposes of this section, a surface-controlled SSSV is considered inoperative if, for a direct hydraulic control system, you have bled the hydraulics from the control line and have isolated it from the hydraulic control pressure. If your controls employ an electro-hydraulic control umbilical and the hydraulic control pressure to the individual well cannot be isolated, a surface-controlled SSSV is considered inoperative if you perform the following:(i) Disable the control function of the surface-controlled SSSV within the logic of the programmable logic controller which controls the subsea well;(ii) Place a pressure alarm high on the control line to the surface-controlled SSSV of the subsea well; and(iii) Close the USV and at least one other tree valve on the subsea well.(b) When warranted by conditions, such as unstable bottom conditions, permafrost, hydrate formation, and paraffin problems, the District Manager must approve the setting depth of the subsurface safety device for a shut-in well on a case-by-case basis.