SNL Application for Production Logging in Hard-to-Recover Gas Reserves Wells

Abstract

Determination of Unit T1-2 (Turonian) flow characteristics in Yuzhno-Russky oil and gas condensate field is a priority area in the development process monitoring. This paper is focused on the informative value of downhole logging surveys conducted for assessment of the reservoir and wellbore flow geometry in the well after hydraulic fracturing. A more detailed consideration of this matter has become possible due to the extensive use of integrated logging suite data during estimation of input parameters for interpretation of pressure transient analysis results. The difficulty of this task was due to the fact that the extent of the vertical fracture in the Turonian formation was several times larger than the perforation zone and, as a result, estimation of the actual net pay based on the conventional logging suite data was hardly practicable. Besides that, due to poor perforation quality the geometry of fracture flow from the reservoir was affected. In view of this, Spectral Noise Logging technique was applied to estimate the reservoir effective thickness contributing to the flow through the fracture created as a result of the hydraulic fracturing job. The integrated logging suite supplemented with SNL-HD tool was run at several differential pressures. As a result of SNL-HD and HPT surveys and subsequent flow modelling, valuable information on fracture flow rates was successfully obtained.