Slim LWD Spectral Gamma Ray for Both Well Placement and Petrophysical Evaluation of Clastics Reservoir in Saudi Arabia

Abstract

With the world's increasing energy demand, it has become more crucial to safely and efficiently maximize recovery from existing assets. This paper focuses is on clastic reservoirs where horizontal wells are drilled to maximize reservoir contact and drainage area. In this environment, well placement and real time Petrophysical evaluation are the keys to maximizing net-to-gross ratios. Technology has recently evolved toward a multidisciplinary approach and to the integration of real-time answer products to address these challenges. To this end, Saudi Aramco has introduced and utilized the slim size LWD spectral Gamma Ray in combination with the multi-functional Logging While Drilling (LWD) technology. By measuring uranium (U), potassium (K) and thorium (Th) in real-time, petrophysicists can identify clay mineral types in addition to the standard evaluation, this information allows for more accurate formation evaluation throughu reliable multimineral petrophysical modeling. It also minimizes uncertainty on the volume of shale (Vsh) estimation, which has an impact on the effective porosity calculations. From real-time 16-bin spectral Gamma Ray data and an X-Y magnetometers to track the azimuthal position of the detectors, a high resolution image is preferred — over the standard Gamma Ray — for properly identifying target entry and for optimizing well trajectory in clastic formations where the lithology changes vertically and laterally.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014