Innovative Method to Understand Flow Behavior in Horizontal Wells with Challenging Borehole Conditions Using Spectral Noise, High Precision Temperature and Pulsed Neutron Logs

Abstract

Abstract Understanding flow behavior in horizontal and highly deviated oil producers is crucial to optimize production strategies and ultimately improve hydrocarbon recovery. Traditionally, multi-phase production logging provides flow profiles and fluids entry points in horizontal wells. However, this technology may be less effective for boreholes with challenging conditions such as the presence of sticky material that cause the loss of measurement tool sensors. This paper proposes several techniques, including spectral noise logging, numerical temperature simulations, and pulsed neutron logging as alternatives to provide flow profiles, identify formation fractures, and characterize possible cross flows in horizontal oil producers with high water cut in the presence of sticky deposits. The tool strings of spectral noise, high precision temperature and pulsed neutron logs contain no mechanical parts or exposed probes that could get affected by sticky deposits. The spectral noise log allows identifying flow zones and fracture signatures. An advanced numerical temperature simulator can be used to quantify total flow that correlates with changes in temperature gradients, while pulsed neutron logs provide water flow using carbon-oxygen for three-phase holdup thereby allowing oil flow to be estimated by subtraction the water flow rate from the total flow. The presence of sticky deposits can compromise the ability of mechanical spinners and exposed probes to provide accurate flow profiles without the use of expensive chemical treatment. The proposed approach will provide a complete high-resolution flow profile comparable to mechanical spinners, while also looking deep into the reservoir and correlating the profile with borehole fractures. Also, the flow profile can be generated using the total acoustic noise power of the turbulent flow. The results of both numerical simulations and acoustic flow velocity compared well with the flow profile provided by the mechanical array production tools. The combination of spectral noise, high precision temperature and pulsed neutron logging suite provides valuable reservoir information without the use of any mechanical parts or exposed probes that could be affected by sticky deposits.