GENERAL30703 - Laserfiche WebLink

Home Browse Search

1. Reduce production wellhead pressure to 300 -350 psig through the 4 Yz"short tubing by flowing the well into the production piping system. 2, Displace the annulus of the short and long strings with lean injection fluid while bleeding pressure off through the 4 yz'short tubing. This will help to prevent the formation of product rings (salt rings). 3. Inject N2 into the 4'/z'long tubing to displace fluid. 4. Flush 4 Yz'short tubing with lean injection fluid, affer flushing with fluid, inject N2 into the 4 yz"short tubing to displace fluid. 5. Shut in well head short and long string, shut injection and production tap lines, depressurize and drain skid. Examples of pressures at the well head that are currently observed during normal operation and pressures at the wellhead that will be observed during the above procedure are as follows: Assumptions Short tubing depth 1915' Long tubing Depth 2320' SG of nahcolite solution 1.07 SG of Injection Fluid 0.9 Production wellhead pressure 325 psig MAID 800 psig Normal Operation: Hydrostatic Pressure at the bottom of the short tubing string - (1915 feet)(0.43 psi/ft)(1.07 sg) + 325 psig = 1148 psig Hydrostatic Pressure at the bottom of the long tubing string - (2320 feet)(0.43 psi/ff)(0.90 sg) + 800 psig = 1698 psig In this example, wellhead pressures of 325 psig and 800 psig would be observed. Displacement Procedure Hydrostatic Pressure at the bottom of the short tubing string - (1915 feet)(0.43 psi/ff)(1.07 sg) + 325 psig = 1148 psig Hydrostatic Pressure at the bottom of the long tubing string - (2320 feet)(0.43 psi/ff)(1.07 sg) + 325 psig = 1392 psig In this example, wellhead pressures of 1148 psig and 1392 psig would be observed at the wellhead during the procedure due to the density difference between the N2 gas and fluid. The pressure that would be observed during the displacement procedure would exceed the MA1P that is currently set forward in American Soda LLP'sEPA Class Ill Permit.