Technical Discussion of Production Casing Issues
Statewide Rules 9 and 46 both require that injected fluids remain confined to the authorized injection/disposal interval. The technical review of the production casing cement evaluates whether confinement of injected fluids can be ensured.
Statewide Rule 13 requires that production casing be cemented from the depth of the casing shoe to a point 600 feet above the casing shoe. Annular cement must also be brought up to a point 600 feet above any potentially productive interval. This general requirement usually provides adequate annular cement to satisfy the fluid confinement requirement. This rule requirement has been in effect since October 17, 1933. Effective January 1, 2014, casing shall be cemented across and above all productive zones, potential flow zones, and/or zones with corrosive formation fluids.
A common deficiency in applications to permit an existing well for injection is that the existing annular cement is inadequate to ensure injected fluid confinement. In this situation, the operator is requested to provide additional cement data or, alternatively, the permit will contain a requirement for a cement squeeze to be done. The additional cement data can take the form of historical cement records, records of prior squeeze attempts, a temperature survey run at the time of cementing, or a cement bond log. If the additional information is not provided or does not demonstrate cement adequacy, then the permit will contain a requirement for a cement squeeze to be done. The permit will also require that a copy of the completion report (Form W-2, W-15) documenting compliance be filed with the initial Mechanical Integrity Test (Form H-5).
If the well does not have sufficient confining cement, has critically short surface casing and is over 35 years old, then the application will be administratively denied. As with any administrative denial, the applicant has the option to request a hearing before the Commission to present the applicants case. The rationale for this policy is that older wells carry inherently higher risk of casing failure during squeeze operations and may result in the loss of the wellbore. An applicant may, at the applicants own risk, undertake the remedial workovers to complete cement coverage from the base of usable quality groundwater to the ground surface, and to provide adequate confinement cement across the injection interval. The applicant may re-apply for the permit after the workover is successfully completed.
