Abstract

The use of radioactive tracer materials for production surveillance monitoring has sometimes been limited by tracer material cost, availability and potential problems in handling. A more favorable alternative to the radioactive tracer is the exploitation of a property which is unique to each element: their different abilities to absorb thermal neutrons. This phenomenon is the principle behind cased-hole pulsed neutron logging in the petroleum industry. However, the inability of standard tools (both radioactive tracer and pulsed neutron) to distinguish between wellbore and annulus environments has limited their usefulness in the past.

The introduction of a new dual burst neutron device that is capable of distinguishing the wellbore from the formation environment has led to potentially wider applications of the pulsed neutron technique. This paper discusses the use of the new tool to monitor injection of Borax treated water in PT Stanvac Indonesia's Jene Field where failures in injector well primary cementation have compromised water injection efficiency.