CHFR Can Better Monitor Gas Sand Pay Zones Hydrocarbon Potential

Gharib M. Hamada, Sr.¹* and Ahmed A. Hegazy, Sr.^2
1KFUPM, Saudi Arabia
²Petrol Balyem Co., Egypt
*[email protected]

The ability to detect and evaluate bypassed hydrocarbon and track fluid movement in sandstone reservoir is vital in the quest to improve production and increase recovery. The main technique, which has been used for monitoring reservoir saturations, is the thermal decay time (TDT) tool. However it is difficult to interpret the TDT data in reservoirs with low-salinity formation water. This problem cannot be solved because TDT measurements depend on the salt content in formation brine. Instead the cased hole formation resistivity tool (CHFR) is proposed to overcome many of the limitations associated with pulsed-neutron tools. This presentation compares the results of reservoir-saturation monitoring obtained from TDT and CHFR logs recorded in wells in an oil field in the Sinai Peninsula, Egypt. The results are referenced to open-hole resistivity logs. It was found that water saturations calculated from CHFR logs are more accurate than TDT log in most cases. Moreover, when a quick decision is required the initial interpretation of CHFR logs always agreed with its quantitative interpretation. In contrast the quick interpretation at TDT log was generally found to be very difficult, and not to agree with its quantitative interpretation.

AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain