This paper presents the first real field application of Electric logging in Pakistan with a new conveyance Technique in order to acquire logging data where conventional Wireline logging data acquisition is not possible due to complex bore hole condition (depth, deviation and hole size etc.).
The new logging technique was successfully conducted on a wild cat exploratory and a development well in Margala North & Tal Blocks respectively. Open-hole logs data was acquired from potential reservoir zones that under normal wireline logging conditions would not have been possible due to high risk of sticking or losing the well due to presence of radioactive sources in the tool string.
In this new technique, logging tools are conveyed to TD inside the drill pipe by wireline or by pumping them with a specialized piston. Once tools reach the TD, they are pumped out of the drill pipe and latched at the bottom, and then pipes are pulled up while data is recorded by the tools hooked with drill pipes. In some of the runs, the logs were acquired while pipes were constantly rotated and mud was circulated through.
The logs acquired through this technique consisted of Laterolog Resistivity, Neutron Porosity, Bulk Density & PE, Sonic Porosity Cross Dipole Sonic and Formation Imaging.
The successful application of this technique in Pakistan has opened new ways to acquire logs data in challenging bore-hole conditions with logging tools and radioactive sources being at low risk of losing down hole.