Peter A. Goode

Pressure-transient behavior of horizontal wells with and without gas cap or aquifer

In this paper analytic solutions are presented in real time and as Laplace transforms for horizontal wells in reservoirs bounded at the top and bottom by horizontal planes. Two types of boundary conditions are considered at these planes, and the Laplace-transform pressure solutions are used to include wellbore-storage and skin effects. Solutions are based on the uniform-flux, line-source solution, but differ from most existing solutions owing to the use of pressure averaging to approximate the infinite-conductivity wellbore condition and use of the correct equivalent wellbore radius for an anisotropic reservoir. New flow periods (regimes) are identified, and simple equations and existence criteria are presented for the various flow periods that can occur during a transient test.

Permeability determination with a multiprobe formation tester

This paper presents analytic models to interpret the pressure transients measured by a multiprobe formation tester. The multiprobe tester discussed consists of three probes. The sink probe generates a pressure pulse by withdrawing fluid from the formation while the resulting pressure response is measured at the sink probe and at each of two observation probes. One observation probe is positioned on the opposite side of the borehole on the same vertical plane as the sink and the other is displaced vertically on the same azimuthal plane as the sink. The effect of the various reservoir parameters on the pressure response is discussed. Application of the models is demonstrated through an actual field example.