DST pressures may not be reliable because the tool is not shut in long enough for pressure to stabilize at final reservoir pressure. A graphical procedure devised by Horner<ref name=ch05r10>Horner, D., R., 1951, Pressure build-up in wells: Proceedings of the Third World Petroleum Congress, The Hague, Section II, p. 503–521.</ref> infers the true reservoir pressure by extrapolating the shut-in periods to infinity. | DST pressures may not be reliable because the tool is not shut in long enough for pressure to stabilize at final reservoir pressure. A graphical procedure devised by Horner<ref name=ch05r10>Horner, D., R., 1951, Pressure build-up in wells: Proceedings of the Third World Petroleum Congress, The Hague, Section II, p. 503–521.</ref> infers the true reservoir pressure by extrapolating the shut-in periods to infinity. |