Ann: Mukuyu-2 wireline logging progress update, page-625

I would not call myself a drilling fluids expert, but I agree with your opinion that there should be less risk in obtaining a sample in the Lower Angwa within 50m of the current TD at 3718m MD because the formation pressure was said to be increasing, which led to a near "on balance situation".

If the leak off properties of the mud (mud cake) are good and the well is slightly overbalanced, then in theory, there should not be too much mud loss, even when the permeability is favourable. However, would it have been wise to go all the way down to 3700m using the MDT on wireline when the cable might stick further up or the shale ledge in the LA causes problems? My answer is no because the well is not exactly vertical. TLC has to be the best short-term solution, but the rate of progress running in and out of hole is slow making the process costly. In addition, they still probably do not have all the required pre-test pressure data. I have a feeling they will need to be selective regarding which zones they take samples and pressures if it looks as though the hole is deteriorating. Even the best mud chemistry available isn't going to keep the hole open indefinitely - do you agree? Running the liner is also high priority that's why I am apprehensive.