Geosteering in Swept and Stacked Channel Reservoir - Integrated Approach Using Mathematical Reservoir Modeling Towards Completion Optimization

Abstract

Abstract Bedding characteristics and the vertical fluid distribution are factors that, when not addressed properly, can jeopardize the results of a horizontal drilling campaign. However, the risk and uncertainty can be mitigated by the integrated reservoir and geological modeling approach using recent LWD technological development. this paper will present an analytical roadmap from reservoir modeling toward well placement evaluation and completion optimization. The reservoir context of this study is divided into upper and lower sand packages. The upper sand has two stacked channels separated by a silty layer, thus becoming the main producer reservoir target. The lower sand has one stacked channel, which is expected to be swept (water zone), as indicated by some offset wells having high water cuts. The first roadmap is to build a workflow to geosteer the upper stacked sand packages. The second one simulates the expected swept zone properties and correlates it with Ultra Deep Resistivity. The third roadmap is to evaluate the formation evaluation to enhance the completion optimization. The well was drilled along a 1000ft MD interval at the upper sand package, which first half at the first lobe, then continues to the second lobe at the second half. High-definition Ultra-Deep Resistivity (UDAR) resistivity inversion helps to optimize well placement and maximize reservoir exposure. UDAR Inversion also maps the second layer reservoir properties. The observation at the lower sand lobe with the potential water-swept zone with more than 80 – 90 % saturation in some areas. The information was paired with the information about channel geometry and internal architecture, enabling the delineation of reservoir architecture and properties. Based on this finding, the formation evaluation analysis combined with the UDAR inversion to optimize the inflow control completion design. The success of this well has shown the benefits of utilizing a new deterministic parametric deep resistivity inversion. The information about the channel sands’ extent and geometry, as well as the identification of their internal architecture, has reduced uncertainties and increased reservoir understanding.