True statements about casing design include (select any that apply):
__ Wells without H2S are called “sweet”.
__ A mixture of water and carbon dioxide is very corrosive.
__ Casing grade C-90 was developed with special metallurgy to resist sulfide stress cracking.
__ Casing grade T-95 was developed with special metallurgy to resist sulfide stress cracking.
__ Typically, high temperatures and lower-stress states accelerate hydrogen embrittlement.
__ For sour service, tubular-material selection is based on minimum temperature, yield strength, manufacturing process, and application.
__ Gas systems are sour when the maximum pressure exceeds 265 psi and partial pressure of H2S is greater than 0.05 psi.
__ Multiphase systems are considered sour if the maximum gas/oil ratio is less than 5,000 scf/bbl and the maximum pressure exceeds 265 psi, and H2S partial pressure in the gas phase is greater than 0.05 psi.
__ Multiphase systems are considered sour if the maximum gas/oil ratio is less than 5,000 scf/bbl and the maximum pressure is less than 265 psi, and H2S partial pressure in the gas phase is greater than 10 psi.
__ Multiphase systems are considered sour if the maximum gas/oil ratio is less than 5,000 scf/bbl and the gas phase contains more than 15 H2S.
These types of questions come from Textbook Series and some are pretty detailed. Much of the information ia also in the Handbook Series. At a minimum, I would know the basics, and these these types of questions have been selected as such.
X Casing is classified according to five properties: the manner of manufacture, steel grade, type of joints, length range, and the wall thickness unit weight (HS2 P288). X Wells without H2S are called “sweet” (TS12 P405). X A mixture of water and carbon dioxide is very corrosive (TS12 P405). X Casing grade C-90 was developed with special metallurgy to resist sulfide stress cracking (TS12 P405). X Casing grade T-95 was developed with special metallurgy to resist sulfide stress cracking (TS12 P405).
__ Typically, high[low] temperatures and lower[higher] stress states accelerate hydrogen embrittlement (TS12 P405). X For sour service, tubular-material selection is based on minimum temperature, yield strength, manufacturing process, and application (TS12 P406). X Gas systems are sour when the maximum pressure exceeds 265 psi and partial pressure of H2S is greater than 0.05 psi (TS12 P406). X Multiphase systems are considered sour if the maximum gas/oil ratio is less than 5,000 scf/bbl and the maximum pressure exceeds 265 psi, and H2S partial pressure in the gas phase is greater than 0.05 psi (TS12 P406). X Multiphase systems are considered sour if the maximum gas/oil ratio is less than 5,000 scf/bbl and the maximum pressure is less than 265 psi, and H2S partial pressure in the gas phase is greater than 10 psi (TS12 P406). X Multiphase systems are considered sour if the maximum gas/oil ratio is less than 5,000 scf/bbl and the gas phase contains more than 15 H2S (TS12 P406).
