| (IV) the executive director may allow the use of an alternate to subclauses (I) and (II) of this clause when an alternative will provide equivalent or better information; and (iii) for intermediate and long string casing: (I) spontaneous potential, resistivity, natural gamma, compensated density and/or neutron porosity, dipmeter/fracture finder, and caliper logs, before the casing is installed; (II) a cement bond with variable density log, casing inspection, and temperature logs after casing is set and cemented, and an inclination survey; and (III) any other test required by the executive director; and (iv) a mechanical integrity test consisting of: (I) a pressure test with liquid or gas; (II) a radioactive tracer survey; (III) a temperature or noise log; (IV) a casing inspection log, if required by the executive director; and (V) any other test required by the executive director. (B) Pressure tests. Surface casing shall be pressure tested to 1,000 pounds per square inch, gauge (psig) for at least 30 minutes, and long string casing shall be tested to 1,500 psig for at least 30 minutes, unless otherwise specified by the executive director. (C) 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, bulk density, and other necessary tests. (8) Injectivity tests. After completion of the well, injectivity tests shall be performed to determine the well capacity and reservoir characteristics. Surveys shall be performed to establish preferred injection intervals. Prior to performing injectivity tests, the bottom hole pressure, bottom hole temperature, and static fluid level shall be determined, and a representative sample of formation fluid shall be obtained for chemical analysis. Information concerning the fluid pressure, temperature, fracture pressure and other physical and chemical characteristics of the injection and confining zones shall be determined or calculated. (9) Construction and workover supervision. All phases of well construction and all phases of any well workover shall be supervised by qualified individuals acting under the responsible charge of a licensed professional engineer or licensed professional geoscientist, as appropriate, with current registration under the Texas Engineering Practice Act or Texas Geoscience Practice Act, who is knowledgeable and experienced in practical drilling engineering and who is familiar with the special conditions and requirements of injection well construction. (10) The executive director shall have the opportunity to witness all cementing of casing strings, logging and testing. The owner or operator shall submit a schedule of such activities to the executive director at least 30 days prior to commencing drilling of the well. The executive director shall be given at least 24 hour notice before each activity in order that a representative of the executive director may be present. (b) Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals shall be constructed in compliance with the following standards: (1) 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. (2) Wells shall be cased and cemented to prevent the movement of fluids into or between underground sources of drinking water. 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 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, diameter, nominal weight, length, joint specification, and construction material); (E) Corrosiveness of injected fluid, formation fluids, and temperatures; (F) Lithology of injection and confining intervals; and (G) Type or grade of cement. (3) Injection wells, except those municipal wells injecting non-corrosive wastes or those using an alternative as provided by subparagraph (A) of this paragraph shall inject fluids through tubing with a packer set immediately above the injection zone, or tubing with an approved fluid seal as an alternative. The tubing, packer, and fluid seal shall be designed for the expected service. (A) The use of other alternatives to a packer may be allowed with the written approval of the executive director. To obtain approval, the operator shall submit a written request to the executive director, which shall set forth the proposed alternative and all technical data supporting its use. The executive director shall approve the request if the alternative method will reliably provide a comparable level of protection to underground sources of drinking water. The executive director may approve an alternative method solely for an individual well or for general use. (B) In determining and specifying requirements for tubing, packer, or alternatives the following factors shall be considered: (i) Depth of setting; (ii) Characteristics of injection fluid (chemical content, corrosiveness, and density); (iii) Injection pressure; (iv) Annular pressure; (v) Rate, temperature and volume of injected fluid; and (vi) Size of casing. (4) Appropriate logs and other tests shall be conducted during the drilling and construction of new Class I wells. A descriptive report interpreting the results of such logs and tests shall be prepared by a knowledgeable log analyst and submitted to the executive director. At a minimum, such logs and tests shall include: (A) Deviation checks on all holes constructed by first drilling a pilot hole, and then enlarging the pilot hole by reaming or another method. Such checks shall be at sufficiently frequent intervals to assure that vertical avenues for fluid migration in the form of diverging holes are not created during drilling; and (B) Such other logs and tests as may be needed after taking into account the availability of similar data in the area of the drilling site, the construction plan, and the need for additional information, that may arise from time to time as the construction of the well progresses. In determining which logs and tests shall be required, the following logs shall be considered for use in the following situations: (i) For surface casing intended to protect underground sources of drinking water: (I) Resistivity, spontaneous potential, and caliper logs before the casing is installed; and (II) A cement bond, temperature, or density log after the casing is set and cemented. (ii) For intermediate and long strings of casing intended to facilitate injection: (I) Resistivity, spontaneous potential, porosity, and gamma ray logs before the casing is installed; (II) Fracture finder logs; and (III) A cement bond, temperature, or density log after the casing is set and cemented. (5) At a minimum, the following information concerning the injection formation shall be determined or calculated for new Class I wells authorized to inject only nonhazardous desalination concentrate or nonhazardous drinking water treatment residuals: (A) Fluid pressure; (B) Temperature; (C) Fracture pressure; (D) Other physical and chemical characteristics of the injection matrix; and (E) Physical and chemical characteristics of the formation fluids. |
