How does the formation respond to production or injection? How do we measure the production profile and saturation change in our wellbore?
To establish production profile, we use production logging tools (PLT).
For vertical well or single phase flow, we use a PLT tool string with single inline and fullbore spinner. In horizontal hole with multiphase flow, we use multi spinners and multi sensors holdup tools.
We then complement the PLT run with Pulsed Neutron Logs. To measure the changes in saturation over time, we use sigma time lapse logs. In some situation where sigma is adversely affected by high salinity, or when sigma oil value and sigma value has similar values, we run the pulsed neutron log in Carbon/Oxygen (C/O) mode.
Sometimes, we run cased hole resistivity (CHFR) and cased hole formation testers (CHDT). We only use CHDT and CHFR if if other cased hole logs could not be used. We also run temperature log with spectral noise logs to establish the flow profile across our wells, but we rarely do this.
We run three types of Production Logs. Click the individual link to learn more about it.
For vertical well and a single fluid phase: PLT [coming soon]
For horizontal wells with two or three phase fluids: Multiple sensors PLT [coming soon]
For low rate or when PLT is not accessible: Spectral Noise and Temperature Logs [coming soon]