Cost-Effective Evaluation of Geological Reserves using Optimal Logging Suite in Exploration Well Drilled through Multilayer Hydrocarbon-Bearing Clastic Formations in West Kazakhstan

Abstract

Modern advanced logging suite and wireline formation tester (WFT) were used for prompt and cost-effective hydrocarbon reserves evaluation for well, drilled through multi-layer clastic formations on unexplored block of the oilfield in West Kazakhstan. Based on acquired comprehensive open-hole wireline logging data and data interpretation results, cased-hole well testing program was severely minimized. Described in this work appraisal well was drilled thru 16 hydrocarbon-bearing clastic formations of Jurassic and Triassic age deposits. Employed logging suite included quad-combo and nuclear magnetic resonance (NMR) tool for accurate evaluation of required petrophysical properties. Quick-look log data interpretation allowed to derive formations properties and their saturation profiles, preliminary delineate several fluid contact levels, as well as prepare optimized formation testing program. WFT was used to measure formation pressure and fluid mobility, as well as to confirm or clarify formation saturation and fluid contacts, capture representative samples of reservoir oil and gas. Current case study demonstrates cost-effective approach of obtaining all the required information for quick estimation of hydrocarbons geological reserves for multi-layer clastic formations. Although large number of reservoirs were confidently characterized, described in this work single well formations evaluation, and testing in open hole took less than two weeks. After setting casing, five out of sixteen productive intervals were perforated and tested, whereafter well was turned into production. Since conventional cased hole testing was performed only for reservoirs, which were required prove of commercial flow, entire well reservoirs testing program was drastically reduced. Described study demonstrates modern and cost-effective way of comprehensive evaluation of hydrocarbon deposits for multi-layer clastic formations of fluvial origin.