La. Admin. Code tit. 43 § XVII-3119

Current through Register Vol. 50, No. 11, November 20, 2024

Section XVII-3119 - Well Construction and Completion

A. General Requirements

1. All materials and equipment used in the construction of the salt cavern well and related appurtenances shall be designed and manufactured to exceed the operating requirements of the specific project. Consideration shall be given to depth and lithology of all subsurface geologic zones, corrosiveness of formation fluids, hole size, anticipated ranges and extremes of operating conditions, physical and behavioral characteristics of the injected and disposed material under the specific range of operating conditions, subsurface temperatures and pressures, type and grade of cement, and projected life of the salt cavern well.

2. All salt cavern wells and salt caverns shall be designed, constructed, completed, and operated to prevent the escape of injected or disposed materials out of the salt stock, into an underground source of drinking water, or otherwise create or cause pollution or endanger the environment or public safety. All phases of design, construction, completion, and testing shall be prepared and supervised by qualified personnel.

B. Open Borehole Surveys

1. Open hole wireline surveys that delineate subsurface lithologies, formation tops (including top of cap rock and salt), formation fluids, formation porosity, and fluid resistivities shall be done on wells from total well depth to either ground surface or base of conductor pipe. Wireline surveys shall be presented with gamma-ray and, where applicable, spontaneous potential curves. All surveys shall be presented on a scale of 1 inch to 100 feet and a scale of 5 inches to 100 feet.

2. Gyroscopic multi-shot surveys of the borehole shall be taken at intervals not to exceed every 100 feet of drilled borehole.

3. Where practicable, caliper logging to determine borehole size for cement volume calculations shall be done before running casings.

C. Casing and Cementing. Except as specified below, the wellbore of the salt cavern shall be cased, completed, and cemented according to rules and regulations of the Office of Conservation and good petroleum industry engineering practices for wells of comparable depth that are applicable to the same locality of the salt cavern. Design considerations for casings and cementing materials and methods shall address the nature and characteristics of the subsurface environment, the nature of injected and disposed materials, the range of conditions under which the well, cavern, and facility shall be operated, and the expected life of the well including closure and post-closure.

1. Cementing shall be by the pump-and-plug method or another method approved by the Office of Conservation and shall be circulated to the surface. Circulation of cement may be done by staging.

a. For purposes of these rules and regulations, circulated (cemented) to the surface shall mean that actual cement returns to the surface were observed during the primary cementing operation. A copy of the cementing company's job summary or cementing ticket indicating returns to the surface shall be submitted as part of the pre-operating requirements of §3127

b. If returns are lost during cementing, the owner or operator shall have the burden of showing that sufficient cement isolation is present to prevent the upward movement of injected or disposed material into zones of porosity or transmissive permeability in the overburden along the wellbore and to protect underground sources of drinking water.

2. Surface casing shall be set to a depth into a confining bed below the base of the lowermost underground source of drinking water. Surface casing shall be cemented to surface where practicable.

3. All salt cavern wells shall be cased with a minimum of two casings cemented into the salt. The surface casing shall not be considered one of the two casings of this Subparagraph.

4. New wells drilled into an existing salt cavern shall have an intermediate casing and a final cemented casing set into the salt. The final cemented casing shall be set a minimum distance of 300 feet into the salt and shall make use of a sufficient number of casing centralizers.

5. The following applies to wells existing in salt caverns before the effective date of these rules and regulations and are being converted to salt cavern waste disposal. If the design of the well or cavern precludes having distinct intermediate and final casing seats cemented into the salt, the wellbore shall be cased with two concentric casings run from the surface of the well to a minimum distance of 300 feet into the salt. The inner casing shall be cemented from its base to surface.

6. The intermediate and final casings shall be cemented from their respective casing seats to the surface when practicable.

D. Casing and Casing Seat Tests. When doing tests under this paragraph, the owner or operator shall monitor and record the tests by use of a surface readout pressure gauge and a chart or a digital recorder. All instruments shall be properly calibrated and in good working order. If there is a failure of the required tests, the owner or operator shall take necessary corrective action to obtain a passing test.

1. Casing. After cementing each casing, but before drilling out the respective casing shoe, all casings shall be hydrostatically pressure tested to verify casing integrity and the absence of leaks. For surface casing, the stabilized test pressure applied at the surface shall be a minimum of 500 pounds per square inch gauge (PSIG). The stabilized test pressure applied at the surface for all other casings shall be a minimum of 1,000 PSIG. All casing test pressures shall be maintained for one hour after stabilization. Allowable pressure loss is limited to five percent of the test pressure over the stabilized test duration.

2. Casing Seat. The casing seat and cement of intermediate and production casings shall each be hydrostatically pressure tested after drilling out the casing shoe. At least 10 feet of formation below the respective casing shoes shall be drilled before the test. The test pressure applied at the surface shall be the greater of 1,000 PSIG or 125 percent of the maximum predicted salt cavern operating pressure. The appropriate test pressure shall be maintained for one hour after pressure stabilization. Allowable pressure loss is limited to 5 percent of the test pressure over the stabilized test duration.

3. Casing or casing seat test pressures shall never exceed a pressure gradient equivalent to 0.80 PSI per foot of vertical depth at the respective casing seat or exceed the known or calculated fracture gradient of the appropriate subsurface formation. The test pressure shall never exceed the rated burst or collapse pressures of the respective casings.

E. Cased Borehole Surveys. A cement bond with variable density log (or similar cement evaluation tool) and a temperature log shall be run on all casings. The Office of Conservation may consider requests for allowances for wireline logging in large diameter casings or justifiable special conditions.

1. It shall be the duty of the well applicant, owner or operator to prove adequate cement isolation on all cemented casings. Remedial cementing shall be done before proceeding with further well construction, completion, or conversion if adequate cement isolation between the salt cavern well and other subsurface zones cannot be demonstrated.

2. A casing inspection log (or similar log) shall be run on the final cemented casing.

F. Hanging Strings. Without exception or variance to these rules and regulations, all salt cavern wells shall be completed with at least two hanging strings. One hanging string shall be for waste injection; the second hanging string shall be for displacing fluid out of the salt cavern from below the blanket material. Hanging strings shall be designed with a collapse, burst, and tensile strength rating conforming to all expected operating conditions, including flow induced vibrations. The design shall also consider the physical and chemical characteristics of fluids placed into and/or withdrawn from the salt cavern.

G. Wellhead Components and Related Connections. All wellhead components, valves, flanges, fittings, flowlines, and related connections shall be manufactured of steel. All components shall be designed with a test pressure rating of at least 125 percent of the maximum pressure that could be exerted at the surface. Selection and design criteria for components shall consider the physical and chemical characteristics of fluids placed into and/or withdrawn from the salt cavern under the specific range of operating conditions, including flow induced vibrations. The fluid withdrawal side of the wellhead (if applicable) shall be rated for the same pressure as the waste injection side. All components and related connections shall be maintained in good working order and shall be periodically inspected by the operator.

La. Admin. Code tit. 43, § XVII-3119

Promulgated by the Department of Natural Resources, Office of Conservation, LR 29:927 (June 2003).

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:4 et seq.