Location - Sai Krishna Colony (behind Sai Baba Temple)-Old Bowenpally-Secunderabad

We had done a Geological survey & as per the expert's recommendation we prepared to go for a bore. The recommended depth for water source was app. 1000'-0.

On 05-06-08, we drilled bore (6.5"size) well in our apartments.We went up to 350'-0 and the driller told that loose soil(below 6 mm metal size - Grey in colour) was found and could not drill further as the same collapsing when the drill bit was taking out. At 350'0 we found water size approximately  one inch only.

PVC casing pipe was put up to 80'0 from the top. We were told that after 100'-0 rock was found and below that the loose soil was found.
Now the  depth of bore well was around 170'0. (after further collapse).  The driller could not put the Perforated casing  from 300'-0 to 350'-0. Having put the same the drill might have been gone further.

We would like have expertise opinion regarding the following.

a) How to over come this problem?
b) Can we use the same bore for re drilling and perforated casing can be used or  not? If so How to go about it?
c) If option (b) is not feasible at what distance we have to drill the new bore and how to go about it?
d) Is there a solution for the same?

Kindly provide advice,

N.Ramakrishna
n.ramakrishna@tataprojects.com