Geology Quality: A Method of Using 3D Geology Model Data for Completion and Fracturing Optimization in Horizontal Wells

Abstract

Abstract Engineered completion designs consider reservoir quality (RQ) and completion quality (CQ) for horizontal well completion optimization. This is more effective than the geometric strategy that is sometimes used. However, both RQ and CQ are derived from the wellbore logs, which means the true geology and reservoir properties inside the geology model (e.g., the thickness of the pay zone or the properties of the rocks) are not fully utilized. That information is often hidden inside the 3D geological model grid properties, and the current completion and fracturing practice cannot use 3D data for optimizations. To address this challenge, we define geology quality (GQ) via 3D models, which aims to support completion and fracturing optimizations with geology considerations quantitatively. GQ is generated by projecting the total effective grid property to the wellbore, so that all the grid in 3D space that is potential for production contribution is cumulated on the nearest wellbore in the form of a 1D wellbore log. This allows GQ to be used in combination with RQ and CQ. While RQ and CQ answer the completion staging design and perforation refinement, GQ is especially useful for the design parameter variations of the hydraulic fracturing. Recently, the GQ concept was used in a six-well campaign in an Ordos shale oil project. In this case, GQ was generated based on the grid property of the 3D geology model. The fracturing parameters, particularly the volume and rate, were designed in proportion to the GQ level along the wellbore for each well. Chemical tracer was pumped into two wells to measure the contribution along the laterals, which also aimed to verify GQ practice. The production results from the campaign outperform the offset platforms and the tracer results from two wells match GQ calculations. GQ is an important new element to enrich the current existing geoengineering workflow. Case studies show the definition and application of GQ not just improve the consistency of the job design, execution, and evaluations, but also enhance the productivity of the well. The concept of using the 3D geology model quantitatively in the form of GQ ultimately helps to upgrade the engineered completion to the next level.