Advancement in Slim LWD Tool Measurement Improves Precision in Geosteering for Complex Lithology Reservoirs

The challenge in the industry today is to maximize recovery from existing assets that require drilling and geosteering in complex clastic reservoirs. Consequently, optimization of the well trajectories while drilling this type of formation is vitally important to achieve the maximum production from each drainage point. Therefore,sophisticated geosteering capabilities coupled with technical support is important, especially when the lateral is planned to be drilled in the direction of the minimum stress. The borehole is normally slim with horizontal section exceeding 3,000 ft. In response to the above challenge a slim azimuthal spectral gamma ray tool (4.75 inches) has been used as a solution for proactive geosteering which provides real time petrophysical evaluation in the complex clastic reservoirs. The ability to measure uranium (U), potassium (K), and thorium (Th) in combined with resistivity, density, and neutron and sonic successfully optimized the path through the sweet spot in the reservoir thus avoiding the tight non-reservoirs sandstones. This paper shares the results of wells geosteered using LWD Spectral Gamma combined with quad-combo data and the real time petrophysical model for shaly-sand evaluation using Multimin models. In addition, this paper discusses the advantages of real time geo-mechanics evaluation which leads to successful geosteering.