(a) Wells shall be sited in such a fashion that they inject into a formation which is beneath the lowermost formation containing, within one quarter mile of the well bore, an underground source of drinking water (USDW).
(b) Plans and specifications. Except as specifically required in the terms of the disposal well permit, the drilling and completion of the well shall be done in accordance with all permit application plans and specifications.
(c) Any proposed changes to the plans and specifications must be in accordance with §331.62(a)(3) of this title (relating to Construction Standards).
(d) Casing and cementing.
  (1) Wells shall be cased and cemented to prevent the movement of fluids into or between USDW. The casing and cement used in the construction of each newly drilled well shall be designed for the life expectancy of the well. In determining and specifying casing and cementing requirements, the following factors shall be considered:
    (A) depth of lowermost USDW or freshwater aquifer;
    (B) depth to the injection zone;
    (C) injection pressure, external pressure, internal pressure, and axial loading;
    (D) hole size;
    (E) size and grade of all casing strings (wall thickness, diameter, nominal weight, length, joint specification, and construction material);
    (F) the maximum burst and collapse pressures, and tensile stresses which may be experienced at any point along the length of the casings at any time during the construction, operation, and closure of the well;
    (G) corrosive effects of injected materials, formation fluids, and temperatures;
    (H) lithology of injection and confining zones;
    (I) types and grades of cement;
    (J) quantity and chemical composition of the injected fluid; and
    (K) cement and cement additives which must, at a minimum, be of sufficient quality and quantity to maintain integrity over the design life of the well.
  (2) Surface casing shall be set to a minimum subsurface depth which extends into a confining bed below the lowest formation containing a USDW or freshwater aquifer.
  (3) A second or long string casing, using a sufficient number of centralizers, shall be set into the salt formation.
  (4) The cement for that part of the casing opposite a salt formation shall be prepared with salt-saturated cementing material.
(e) Injection tubings. Except for circulation of drilling fluids during well construction, all injection activities for bedded salt cavern construction and waste disposal in a bedded salt cavern shall be performed using removable injection tubing(s) suspended from the wellhead.
  (1) All injection activities during bedded salt cavern construction shall be performed with the annulus between the tubing and long string casing filled with a noncorrosive fluid sufficient to protect the long string casing seat.
  (2) All injection of waste into a bedded salt cavern shall be performed through tubing with a packer to seal the annulus between the tubing and casing near the bottom of the casing, or tubing with an approved fluid seal as an alternative. The tubing, packer, and fluid seal shall be designed for the expected service.
(f) Well annulus system factors for consideration. In determining and specifying requirements for a tubing and packer system or tubing with a fluid seal, the following factors shall be considered and addressed:
  (1) depth of setting;
  (2) characteristics of injection fluid and waste;
  (3) injection pressure;
  (4) annular pressure;
  (5) rate, temperature, and volume of injected waste;
  (6) size of casing; and
  (7) tensile, burst, and collapse strengths of the tubing.
(g) Logs and tests.
  (1) Geophysical logging. Appropriate logs and other tests shall be conducted during the drilling and construction phases of the well including drilling into the salt. All logs and tests shall be interpreted by the service company which processed the logs or conducted the test, or by other qualified persons. At a minimum the following logs and tests shall be conducted:
    (A) deviation checks on all holes, conducted at sufficiently frequent intervals to assure that avenues for fluid migration in the form of diverging holes are not created during drilling;
    (B) a spontaneous potential and resistivity log;
    (C) from the ground surface or from the base of conductor casing to the total investigated depth including all core hole or pilot hole:
      (i) natural gamma ray log;
      (ii) compensated density and neutron porosity logs;
      (iii) acoustic or sonic log;
      (iv) inclination (directional) survey; and
      (v) caliper log (open hole);
    (D) from the ground surface or from the base of conductor casing to the lowermost casing seat:
      (i) cement bond with variable density log;
      (ii) temperature log (cased hole); and
      (iii) casing inspection log; and
    (E) fracture detector log from the base of the surface casing to the total investigated depth including all core hole or pilot hole.
  (2) Pressure tests.
    (A) After installation and cementing of casings, and before drilling out the cemented casing shoe, surface casing shall be pressure tested at mill test pressure or 80% of the calculated internal pressure at minimum yield strength, and the intermediate and long string casing shall be tested to 1,500 pounds per square inch (psi) for 30 minutes, unless otherwise specified by the executive director.
    (B) After drilling out the cemented long string casing shoe, and before drilling more than 100 feet of core hole or pilot hole below the long string casing shoe, the bond between the salt, cement, and casing shall be tested at a pressure of 0.8 psi per foot of depth.
    (C) The pilot hole and/or core hole shall be tested between the long string casing shoe and the total investigated depth, at a casing seat pressure of 0.8 psi per foot of depth.
  (3) Coring.
    (A) Core samples. Full-hole cores shall be taken from selected intervals of the injection zone and lowermost overlying confining zone; or, if full-hole coring is not feasible or adequate core recovery is not achieved, sidewall cores shall be taken at sufficient intervals to yield representative data for selected parts of the injection zone and lowermost overlying confining zone. Core analysis shall include a determination of permeability, porosity, and bulk density.
    (B) In situ permeability, lithostatic gradients, and fracture pressure gradients shall be determined in the core hole for the salt, within the cavern injection interval.
  (4) Before commencement of injection for cavern construction, any portion of the pilot hole or core hole that extends beyond the intended wall of the cavern shall be filled with salt-saturated cement from total investigated depth back to the designed cavern boundary.
  (5) Well integrity testing. The mechanical integrity of a well must be demonstrated before initiation of injection activities. A mechanical integrity test shall consist of:
    (A) a pressure test with liquid or gas;
    (B) a temperature, noise log, or oxygen activation log;
    (C) a casing inspection log, if required by the executive director; and
    (D) any other test required by the executive director.
(h) Compatibility. All well materials must be compatible with formations and fluids with which the materials may be expected to come into contact. A well shall be deemed to have compatibility as long as the materials used in the construction of the well meet or exceed standards developed for such materials by the American Petroleum Institute, the American Society for Testing Materials, or comparable standards acceptable to the executive director.
(i) Pre-injection units.
  (1) The injection pump system shall be designed to assure that the surface injection pressure limitations authorized by the well permit shall not be exceeded.
  (2) Instrumentation shall be installed to continuously monitor changes in annulus pressure and annulus fluid volume for the purpose of detecting well malfunctions.
  (3) Pre-injection units, while allowing for pressure release, shall be designed to prevent the release of unauthorized cavern contents to the atmosphere.
Cont'd...