Looking for 3D detectors for a borewell in Bangalore Rural

I have a borewell with 800 ft depth with a single source of water at 550 ft, casing of 48ft but I have motor of 10hp and it pulls out water for only 15-20 min in a 2 inch pipe. 

1. I would like to do 3D mapping and see if I can get more water below

2. What other options I can try out, if I replace 10hp motor with a 7.5hp how would I know if that works or not?