40 CFR § 147.503 - Existing Class II (except enhanced recovery and hydrocarbon storage) wells authorized by rule.

Maximum injection pressure. To meet the operating requirements of § 144.28(f)(3)(i) of this chapter, the owner or operator shall use an injection pressure at the well head no greater than the pressure calculated using the following formula:

Pm = (0.733−0.433 Sg)d

where:

Pm = injection pressure at the well head in pounds per square inch

Sg = specific gravity of injected fluid (unitless)

d = injection depth in feet.

[49 FR 45306, Nov. 15, 1984]