LAC 43:XIX.4909. Casing Program

A. Conductor Pipe 1. Conductor pipe is that pipe ordinarily used for the purpose of supporting unconsolidated surface deposits. The use and removal of conductor pipe during the drilling of any geothermal resource well shall be at the option of the operator. B. Surface Casing 1. Casing to be set shall be determined from TABLE NUMBER ONE hereof: Table Number One Total Depth of Contract (Feet) | Casing Required (Feet) | No. of Sacks Cement | Surface Casing Test Pressure (psi) 0-2500 | 100 | 200 or circulate to surface* | 300 2500-3000 | 150 | 500 “ | 600 3000-4000 | 300 | 500 “ | 600 4000-5000 | 400 | 500 “ | 750 5000-6000 | 500 | 500 “ | 1000 6000-7000 | 800 | 500 “ | 1000 7000-8000 | 1000 | 500 “ | 1000 8000-9000 | 1400 | 500 “ | 1000 9000-Deeper | 1800 | 500 “ | 1000 *Circulate to the Surface shall mean amount of cement necessary to fill the theoretical annular space plus ten percent. In known low-pressure areas, exceptions to the above may be granted by the Commissioner or his agent. If, however, in the opinion of the Commissioner or his agent, the above regulation shall be found inadequate, an additional or lesser amount of surface casing and/or cement or test pressure shall be required for the purpose of safety and the protection of fresh water sands. But in all cases, surface casing will be set below the base of the lowest known aquifers containing three thousand (3000) mg per liter of total dissolved solids. 2. Surface casing shall be tested before drilling the plug by applying a minimum pump pressure as set forth in TABLE ONE. If at the end of 30 minutes the pressure gauge shows a drop of ten percent of test pressure as outlined in TABLE ONE, the operator shall be required to take such corrective measures as will insure that such surface casing will hold said pressure for 30 minutes without a drop of more than ten percent of the test pressure. The provisions of D-7 of this Section, for the producing casing, shall also apply to the surface casing. 3. Cement shall be allowed to stand a minimum of 12 hours under pressure before initiating test or drilling plug. "Under Pressure" is complied with if one float valve is used or if pres­sure is held otherwise. C. Intermediate Casing 1. Intermediate casing is that casing used as protection against caving of heaving formations or when other means are not adequate for the purpose of segregating upper strata. 2. If an intermediate casing string is deemed necessary by the district manager for the prevention of underground waste, such regulations pertaining to a minimum setting depth, quality of casing, and cementing and testing of sand, shall be determined by the Office of Conservation after due hearing. The provisions of D-7 of this Section, for the producing casing, shall also apply to the intermediate casing. D. Producing Casing 1. Producing casing is that casing used for the purpose of segregating the horizon from which production is obtained and affording a means of communication between such horizons and the surface. 2. The producing casing shall consist of new or reconditioned casing, tested at mill test pressure or as otherwise designated by the Office of Conservation and set at a sufficient depth to seal off all formations above the horizon in which the well is to be completed. The position of the horizon shall be determined by coring, testing, or electrical logging, or other satisfactory method, and the producing casing shall be bottomed and cemented at a point below or above the geothermal geopressured reservoir, if determinable and practicable. 3. Cement shall be placed by the pump-and-plug method, or another method approved by the Office of Conservation. Sufficient cement shall be used to fill the calculated annular space behind the casing to such a point as in the opinion of the district manager local conditions require to protect the known oil and gas and geothermal reservoir(s), and all other formations occurring above; but in every case, no less cement shall be used than the calculated amount neces­sary to fill the annular space to a point at least, but not less than 500 feet above the bottom of the intermediate string of casing. 4. The amount of cement to be left remaining in the casing, until the requirements of Paragraph 5 of this Section have been met, shall not be less than 20 feet. This shall be accomplished through the use of a float-collar, or other approved or practicable means, unless the full-hole cementer, or its equivalent, is used. 5. Cement shall be allowed to stand a minimum of 12 hours under pressure and a minimum total of 24 hours before initiating test or drill plug in the producing casing. "Under Pressure" is complied with if one or more float valves are employed and are shown to be holding the cement in place, or when other means of holding pressure is used. When an operator elects to perforate and squeeze or to cement around the shoe, he may proceed with such work after twelve hours have elapsed after placing the first cement. 6. Before drilling the plug in the producing casing, the casing shall be tested by pump pressure, as determined from Table Number Two. If at the end of 30 minutes the pressure gauge shows a drop of 10 percent of the test pressure or more, the operator shall be required to take such corrective measures as will insure that the producing casing is so set and cemented that it will hold said pressure for 30 minutes without a drop of more than 10 percent of the test pressure on the gauge. Table Number Two (Intermediate and Producing Casing) Depth Set (Feet) | No. of Sacks of Cement | Producing String Test Pressure (psi) 2000-3000 | 200) | But in every case no less cement shall be used than the calculated amount necessary to fill the annular space to a point 500’ above the producing formation but not less than 500’ above the bottom of the intermediate string of casing | 800 3000-6000 | 300) | But in every case no less cement shall be used than the calculated amount necessary to fill the annular space to a point 500’ above the producing formation but not less than 500’ above the bottom of the intermediate string of casing | 1000 6000-9000 | 500) | But in every case no less cement shall be used than the calculated amount necessary to fill the annular space to a point 500’ above the producing formation but not less than 500’ above the bottom of the intermediate string of casing | 1200 9000-Deeper | 500) | But in every case no less cement shall be used than the calculated amount necessary to fill the annular space to a point 500’ above the producing formation but not less than 500’ above the bottom of the intermediate string of casing | 1500 7. If the commissioner's agent is not present at the time designated by the operator for inspection of the casing tests of the producing casing, the operator shall have such tests witnessed. An affidavit of test, on the form prescribed by the Office of Conservation, signed by the operator and witness, shall be furnished to the District Office of the Office of Conservation showing that the test conformed satisfactorily to the abovementioned regulations before proceeding with the completion. If test is satisfactory, normal operations may be resumed immediately. 8. If the test is unsatisfactory, the operator shall not proceed with the completion of the well until a satisfactory test has been obtained. E. Tubing and Completion 1. All flowing wells shall be produced through tubing set on a packer or, as an alternate method and upon approval by the district manager, through casing provided that such casing is cemented back to the next string. 2. When a well develops a casing pressure upon completion equivalent to more than three-quarters of the internal pressure that will develop the minimum yield point of the casing, such well shall be required by the district manager to be killed and the leak repaired so as to keep such excessive pressure off of the casing. F. Wellhead Connections 1. Wellhead connections shall be tested at a pressure indicated by the district manager in conformance with conditions existing in areas in which they are used.