geoservices mudlogging problems

[pendex]

hi everybody
i m doing a investigation about some problems with mudlogging data......we drilled until 3500 m and we found 4 interesting zones.....we got in range of 90 000 ppm at 180 000 ppm of gas ..... the software of geoservice showed a triangle that according to software and wellsite engineers theses zones contained a comercial amount of condensate.
then schlumberger logged the well with GR, SP, others and XPT (Pressure xpress) and determined that the well was dry and with water..........the boss were 2 days meeting to decide to run down casing, the geologist of the company decide that we had to run casing so we did...we found nothing except black oil with very low formation pressure.

why we got high values of gas ppm?
how works the geoservice software to decide if in the well we have gas?'
why we found oil and we didnt detect it?
what i can do to not decide wrong about running casing or abandon the well?

thank for help

[mariosarmiento]

I don´t know a lot of that topic but I think that you need calibrate your chromatograph so that the pixler are good, and then you see if you have a producted gas and/or production oil. Moreover, you could see the oil shows.

[radkusuma]

3 Kinds hydrocarbon sensor for Geoservices; FCP/FGP, GFF and the best one is reserval with 3 varians. You should calibrate them before drilling. and also always check flow line, pressure and flow coming into sensor, this also including the H2 gas supply. If everything within sensor required, it should be a valid sensor reading come into RTM.