020-24 Wyo. Code R. § 24-9

Current through April 27, 2019
Section 24-9 - Construction and operation standards for Class VI wells

(a) The owner or operator must ensure that all Class VI wells are designed, at a minimum, to the construction standards set forth by the department and the Wyoming oil and gas conservation commission, as applicable, and constructed and completed to:

  • (i) Prevent the movement of fluids into or between USDWs or into any unauthorized zones;
  • (ii) Permit the use of appropriate testing devices and workover tools; and
  • (iii) Permit continuous monitoring of the annulus space between the injection tubing and long string casing.

(b) Casing and cement or other materials used in the construction of each Class VI well must have sufficient structural strength and be designed for the life of the well.

  • (i) All well materials must be compatible with fluids with which the materials may be expected to come into contact, and meet or exceed standards developed for such materials by the American Petroleum Institute, ASTM International, or comparable standards acceptable to the administrator.
  • (ii) The casing and cementing program must be designed to prevent the movement of fluids into or between USDWs.
  • (iii) In order to allow the administrator to determine and specify casing and cementing requirements, the owner or operator must provide the following information:
    • (A) Depth to the injection zone;
    • (B) Injection pressure, external pressure, internal pressure and axial loading;
    • (C) Hole size;
    • (D) Size and grade of all casing strings (wall thickness, external diameter, nominal weight, length, joint specification and construction material), including whether the casing is new, or used;
    • (E) Composition of the carbon dioxide stream and formation fluids;
    • (F) Down-hole temperatures and pressures;
    • (G) Lithology of injection and confining zones;
    • (H) Type or grade of cement and additives; and
    • (I) Quantity, chemical composition, and temperature of the carbon dioxide stream.
  • (iv) Casing must extend through the base of the lowermost USDW above the injection zone and be cemented to the surface through the use of a single or multiple strings of casing and cement.
  • (v) At least one long string casing, using a sufficient number of centralizers, must be set in a manner so as to create a cement bond through the overlying and/or underlying confining zones(s). The long string casing must extend to the injection zone, must be cemented by circulating cement to the surface in one or more stages, and must be isolated by placing cement and/or other isolation techniques as necessary to provide adequate isolation of the injection zone and provide for protection of USDWs, human health, safety, and the environment.
    • (A) Circulation of cement may be accomplished by staging. The administrator may approve an alternative method of cementing in cases where the cement cannot be recirculated to the surface, provided the owner or operator can demonstrate by using logs that the cement does not allow fluid movement behind the well bore.
  • (vi) Cement and cement additives must be suitable for use with the carbon dioxide stream and formation fluids and of sufficient quality and quantity to maintain integrity over the operating life of the well.
  • (vii) The integrity and location of the cement shall be verified using technology capable of evaluating cement quality radially with sufficient resolution to identify the location of channels, voids, or other areas of missing cement to ensure that USDWs are not endangered and that human health, safety, and the environment are protected.

(c) All owner and operators of Class VI wells must inject fluids through tubing with a packer set at a depth opposite a cemented interval at the location approved by the administrator.

  • (i) Tubing and packer materials used in the construction of each Class VI well must be compatible with fluids with which the materials may be expected to come into contact and must meet or exceed standards developed for such materials by the American Petroleum Institute, ASTM International, or comparable standards acceptable to the administrator.
  • (ii) In order for the administrator to determine and specify requirements for tubing and packer, the owner or operator must submit the following information:
    • (A) Depth of setting;
    • (B) Characteristics of the carbon dioxide stream (e.g., chemical content, corrosiveness, temperature, and density) and formation fluids;
    • (C) Maximum proposed injection pressure;
    • (D) Maximum proposed annular pressure;
    • (E) Maximum proposed injection rate (intermittent or continuous) and volume of the carbon dioxide stream;
    • (F) Size of tubing and casing; and
    • (G) Tubing tensile, burst, and collapse strengths.

020-24 Wyo. Code R. § 24-9

Amended, Eff. 7/25/2016.