Lessons Learned from Existing Horizontal Fractured Wells on University Lands in the Midland Basin: Rate Transient Analyses Vs Completion and Field Development Optimization

摘要

Unconventional reservoir production heavily depends on a successful hydraulic fracturing treatment. More than 2000 horizontal wells were drilled since 2010 on the University Lands in the Midland Basin. Finding the optimal completion and field development plan on the University Lands acreage is always one of the top priorities for the Texas Oil and Gas Institute (TOGI). A traditional way to evaluate a well performance is to look at the initial production rate, cumulative production at different time period, and estimated ultimate recovery (EUR) based upon decline curve analyses (DCA). The approach is easy-to-use but its prediction may be suboptimal due to lack of considerations in geology, fluid property, completion design, and production operation. Well performance can be also evaluated through reservoir simulation based on a realistic physical model. However, the model building process is usually time-consuming due to the need of integrated study of geology, petrophysics, geomechanics, and reservoir engineering. For this reason, a full-scale model-based simulation usually cannot be done in real-time projects due to constraint on time and resources. In this paper, we show an alternative way to analyze well performance through a multiphase rate transient analysis (RTA) on individual wells. The method is more efficient and it runs on a representative physical model, producing result comparable to what can be achieved through a full-scale simulation study. We identify critical parameters that have significant impact on completion design and field development strategy based on RTA results and observed completion parameters such as cluster spacing, well spacing (fracture half-length) in different areas of University Lands in the Midland Basin.