Welltest 200: PTA Tool Kit

Everything is Broken: Broken hands on broken ploughs, broken treaties, broken vows, broken pipes, broken tools, people bending broken rules…(Bob Dylan). In the spirit of global discordance, let’s look at failed #welltests… Sometimes mysterious, unusual, and bizarre things happen #welltesting, and we have no idea what happened… This well lost 25% of it’s reservoir drive pressure after a 23 h swab evaluation. Following an additional 70 h of flow evaluation the reservoir pressure was 79% depleted. In reservoir modelling we refer to “tank-type” volumetric depletion, and this is a perfect example of a very small tank depleting on test. But unusually small, analytical synthesis could not history match the material balance. Bottom line: everybody has been shaking their heads lost for an explanation…