In particular, high-pressure and intermediate-pressure casing components are susceptible to frequent cracking due to thermo-mechanical low-cycle fatigue at the nozzle fit corner radius and other stress concentration shapes.
The important parameters were as follows: well depth of 3,980 m, dominating radius of 88 m, initial reservoir pressure, Pi, of 40.8 MPa, casing pressure of 43.2 MPa, casing diameter of 14.6 cm, well spacing of 200 m, injection pressure, Pe, of 45 MPa, water injection rate of 150 m3, injection time of 5610 h, and injected water temperature of 18.5 °C.
And then, in light of the features of automatic monitoring instruments, automatic production of CBM wells was divided into four stages (i.e. before casing pressure occurring, casing pressure building, initial gas production and gas production).
This paper presents the use of a model to predict sustained casing pressure (SCP), from early pressure buildup data, as a basis for inherently safer well integrity testing.
On the other hand, the pressures that develop during bull-heading at a high rate must not exceed wellhead pressure rating, tubing or casing burst pressures or the formation breakdown gradient, since this will lead at best to a very inefficient job.
This keeps the total flow rate of liquid somewhat constant throughout the adjustment of casing pressure.
Regulators issued an emergency order March 4 requiring the gas company to perform pressure tests and casing inspections of any wells to be put back into use.
Finally, a well plan which includes pore pressure, fracture pressure, drilling mud policy, casing policy and kick tolerance graph were proposed to give clear picture on well planning on the top of the anticline in pore pressure point of view.
Increased internal pressure requires casing with a higher internal pressure resistance.
Based on this aspect, certain parameters are calculated such as the pressure gradient, casing, temperature and their associated geological and geophysical parameters.
