No abstract

With the gradually increasing applications of fiber-optic distributed temperature sensors (DTS) in unconventional resources exploitation, academic researchers have developed general theoretical models for forward temperature simulation and inverse flow rate profiling during and after stimulation workover. However, there have been no enough field applications for the established theoretical models and some practical issues still exist such as different completion scenarios are still lack of consideration in current models. This paper presents a DTS flow profiling case for a horizontal multi-stage fractured well in tight gas reservoirs with open-hole packer completion scenarios by applying a newly improved theoretical model. In this paper, for the modeling part, we start with the semi-analytical wellbore-fracture-reservoir coupled flow/thermal model but improve it to consider open-hole packer completion scenario. Compared with the conventional cased, cemented and perforated completion style, the fracture initiation points in open-hole stimulated well are more effected by near wellbore in-situ stress field. Therefore, the open-hole packer completion possibly forms a two-fold flow regime. The formation fluid firstly flows through the fracture into the open-hole annular space between formation and the packer liner, then flow along the annular space until meet the frac port on the production pipe. The two-fold flow regime results in double temperature drops due to Joule-Thompson cooling effect. The original theoretical model is improved by adding a simulation sub-region representing open-hole annular which helps to understand the flow and heat transfer inside it. With the improved mathematical model, DTS monitoring data during a three-rate production test in a horizontal multi-stage fractured well in Erdos Basin of China was simulated and analyzed. The improved model with open-hole packer completion was applied and then the gas flow profiling was accomplished.