The Role of Enhanced Production Logging Measurements in Challenging Openhole Horizontal Completions

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe keys to proactive production and reservoir management are production logs that profile fluid entries and diagnose problems in producing wells. Designing optimal production strategies and remedial operations requires highconfidence diagnosis. Production logging in high angle and horizontal wells producing mixtures of various phases is challenging because of complex flow regimes.In this paper we present a field example that uses a new compact, integrated production-logging tool that incorporates the latest technological advances and best practices to address complex production-logging requirements. We are able to demonstrate the added value in terms of comprehensive flow diagnosis.A production logging operation using the new tool, which specializes in horizontal and deviated well logging, was planned to obtain key inputs for the reservoir model and investigate reasons for low well productivity. Production logs from the new tool resulted in accurate flow diagnosis and led to better understanding of complex flow mechanisms across the horizontal section. These enhanced measurements were integrated with borehole imaging information leading to a better understanding of flow contribution from the matrix and fractures. The tool provides a recording of holdup and velocity profiles along the vertical diameter of the borehole cross-section. Three sensor arrays, consisting of six optical probes, six electrical probes, and five spinners, are spread across the wellbore on retractable arms that can be opened and closed with a hydraulic sub to better locate holdup interfaces. The optical probes use the fluid's reflectance to derive the gas holdup, and the electrical probes measure the fluid's impedance to derive the water holdup. The spatial location of the different sensors is accurately known through the use of an integrated relative bearing sensor and a caliper measurement. The direct measurement of the velocity and fluid holdup enhances the capability of the analyst to determine an accurate downhole flow profile.

Temperature-Prediction Model for a Horizontal Well With Multiple Fractures in a Shale Reservoir

“…Mustafa et al (2005) presented a new tool with the miniaturization of the spinners and the mounting of the sensors along a vertical diameter of the wellbore, and its ability to measure the gas velocity and its relatively short length in comparison with conventional tools enable users to better understand their production flow regimes. Zeybek et al (2005) and Mukerji et al (2006) applied the same type of compact new tool presented by Mustafa et al (2005) to the identification of super-permeable zones or conductive fractures and the direct assessment of their flow contributions; determination of water salinity variations to define injection water entry along the wellbore; the evaluation of production pressure loss; and the diagnostics of the downhole flow regime. Fitz et al (2006) also applied the array spinner and array holdup measurements in Chayvo field, and they provided interpretations that are more likely to represent actual downhole conditions than can be achieved from conventional production logging tools.…”