D40 Misconceptions

D40: #AER Directive 40 (aka Guide 40) Initial Pressures… With a minimum eight hours (8 h) of subsurface #welltest pressure data, it doesn’t matter whether-or-not the test meets the 2 kPa Rule, if the data are analyzable. Pressure Transient Analysis (#PTA) has been used for decades to extrapolate build-up and fall-off tests to a theoretically stable point in time (p*). We can analyze (PTA & PITA) F&BU, DFIT, PID, & FLO tests to provide the #AER with extrapolated pressures (p*). The advent of digital data submissions (DDS) required the programming of “business rules” for the Board’s computer to check, before accepting PAS files. Unfortunately, the 2 kPa and 14 Day Business Rules have been misinterpreted and misunderstood.