Quantification of Reservoir Pressure in Multi-Zone Well under Flowing Conditions Using Spectral Noise Logging Technique, Zubair Reservoir, Raudhatain Field, North Kuwait

Abstract

Abstract Monitoring the reservoir pressures throughout the production life of the field is considered as a cornerstone for reservoir management and optimization of the development plans. There are many challenges to have routine and proper pressure records. Multi-zone single completion wells are one of these challenges, where it is difficult to acquire the reservoir pressure for each zone through the conventional pressure gauges. In addition to that, deferring the production or injection of high rate wells for quite time to acquire downhole static pressure data is adding more to these challenges. Raudhatain Zubair Reservoir is a layered reservoir with difference in reservoir pressure from layer to the other. Spectral Noise Logging technique has been utilized to estimate the average reservoir pressure for each perforated layer in a Multi-zone single completion oil producer. The noise logging survey has been carried out under flowing conditions and on different rates. The process of estimation the average reservoir pressure from Noise logging is based on quantification of the noise power under different rates. The signal recorded by SNL has two main parameters: amplitude and frequency. The frequency ranges widely from 8 Hz to 60 kHz, while the amplitude increases with differential pressure. The power of the acoustic noise signal generated by a reservoir fluid flowing from a particular unit is directly proportional to the product of differential pressure and flow rate. Nonlinear relationship between the noise power and bottom-hole flowing pressure has been utilized to estimate the average reservoir pressure which stays valid under monophasic flow conditions for the hydrocarbon to the wellbore. The estimated pressures for each layer from this technique matched the RFT pressure data that have been recorded in the nearby wells and in also RFT data recorded in same well considering the production history. The noise profile has also indicated the effective sand thickness for each layer and investigated flow behind the casing from non-perforated reservoir to the existing perforations. Utilization of the SNL logging to estimate the reservoir pressure is adding more to reservoir surveillance applicable tools that could mitigate some of the existing challenges and aiming to improve the surveillance process under certain circumstances. This paper presents a case of applying the noise logging in an oil producer with the detailed job procedures, measured data, interpretation process, and the final results