Section 711. Voids and lost circulation zones

A. Casing through voids.

1. When a corehole is drilled through a void, the hole shall be drilled at least 30 feet below the void. The annular space shall be cemented from the base of the casing up to the void and every reasonable attempt shall be made to fill the annular space from the top of the void to the surface; or it shall be cemented at least 50 feet into the next higher string or strings of casing that are cemented to the surface and be verified by a cement top log.

2. For good cause shown, the director may approve alternate casing procedures proposed by the permittee, provided that the director is satisfied that the alternative casing procedures are operationally equivalent to the requirements imposed by this section.

3. For good cause shown, the director may impose special requirements on the permittee to prevent communication between two or more voids.

B. Reporting of lost circulation zones. The permittee shall report to the director as soon as possible when an unanticipated void or groundwater horizon is encountered that results in lost circulation during drilling. The permittee shall take every necessary action to protect the lost circulation zone.

Historical Notes

Derived from Volume 15, Issue 02, eff. November 11, 1998; amended, Volume 29, Issue 03, eff. November 8, 2012; Volume 30, Issue 01, eff. October 10, 2013.

Statutory Authority

§§ 45.1-161.3 and 45.1-361.27 of the Code of Virginia.