Productive casing

• Productive casing is the oil and gas well casing program in the last layer of casing from the wellhead has been down to the reservoir through the following. Casing down into the depths, basically the drilling depth.
  Casing is the role of oil and gas to the surface of the channel, and all oil and gas formations isolated to ensure oil and gas pressure leak. After the casing in oil and gas wells into production and maintain a certain level of production to guarantee its quality.
  Production casing cementing quality of, on the one hand bearing as well, is the key to oil and gas test; the other concerns as well, directly affect the well of life.
  The cement seal between the casing and the borehole clearance height above the reservoir at least 500 metres, or until a layer of sleeve of 200 meters.