Identification of Inflow Zones in Low-Rate Horizontal Wells by Spectral Noise Loggin

Abstract

The modern petroleum industry in Russian Federation has been lately focusing on developing fields with complex flow properties typical, for example, to low-permeability reservoirs. Therefore, it is important to identify flow zones in wells, mostly horizontal ones, when producing from such low-permeability reservoirs. This task is complicated not only by the effect of complex well completion components but also by the small specific rates of inflows into the wellbore. The conventional logging techniques do not always yield sufficient information under such conditions. This paper presents the results of a conventional downhole logging suite supplemented with High-Definition Spectral Noise Logging (SNL-HD) and targeted at determining flow profiles in low-rate horizontal producers. A separate objective was to evaluate the SNL-HD efficiency in identifying flow zones in low-permeability carbonate reservoirs. Upon SNL-HD data analysis, depth-specific broadband noises typical to turbulent flows from naturally fractured carbonate reservoirs into the wellbore were identified. The proposed technique is illustrated with four case studies performed in an oilfield situated in Krasnoyarsk Region in the south of the Evenk Municipal District. These cases studied dealing with the survey, results of which that application of SNL-HD in combination with the conventional downhole logging techniques helps to identify flow zones and thereby monitor horizontal well production and work out recommendations on well performance enhancement.