Hi Stefoid and Wayang KulitIn answer to your question, while I...

Hi Stefoid and Wayang Kulit

In answer to your question, while I am certainly no expert I would assume that any deviation caused is due to the hardness of the subsurface and/or the dipping nature of rock beds. One way to overcome this dipping and resultant deflection is to reduce the bit pressure and allowing the drill bit to do the work, hence reduced drill rate. Baraka are silent on degree of deviation however I would suggest it is minimal given the technology available for determining the degree of deviation and the importance of ensuring that the well is as vertical as possible. This should be much of an issue in my opinion except for the blowout in time taken to reach target.

In relation to hydrocarbon generative windows I would suggest they are now lower than 3800m as my interpretation is that it is relative to the Aptian level. As previously pointed out on HC in a response from Baraka the uncertainty is caused by the lack of control wells in the vicinity of Heron. Previous response from Baraka is detailed below.

”Firstly, the depths quoted as "seismic" depths. In other words, depths calculated from the time that sound waves have been generated at the surface, hit a density-contrast surface and travel back to be captured by an array of geophones strung out along the ground - "the seismic line".

The optimal word is "calculated". We have only one control wells in the area and that a long 30km away. Moreover, the travel time of sound waves in the earth are difficult to measure. Because we have little control information, our depths quoted have a margin of error that is not mentioned but usually understood by geoscientists. This is where we may have made a mistake in not mentioning the margin of error that is implied in these depths to the investing fraternity. Depending on the discrepancy of the model stratigraphic section used (Texaco's Autruche-1) in the calculations and the actual one penetrated in the well (Heron-1), there may be over 200m of discrepancy in the calculated and the real depth to a seismic feature, such as a shale-to-(reservoir)sandstone interface at depth.

Secondly, the +/- 2200m and +/- 3600m "targets" are indeed that and we have what appears to be sand-reservoirs evident at these seismic depths. These two reservoirs have what may be interpreted as Direct-Hydrocarbon-Indicators. This does not detract from the fact that the whole section between these depths is prospective, and ANY sand-body between 2200m and 3600m may or may not be hydrocarbon-bearing, potentially to economic levels.”

Another long winded post – apologies.

Danash