New Understanding of Temperature Change Rules of Horizontal Sections of Different Well Body Structures and the Relationship Between Production Capacity and Stimulation Parameters Based on Das/Dts
Authors: Qiao Yan , Zhang Yang , Gong Wanxing , Wu Xi , Wang Siqi 
Published: May 2024

Since 2019 DAS has been widely used with horizontal well fracturing dynamic monitoring and interpretation analysis, achieving quantitative calculation of fluid and sand production in each fracturing section and cluster, however, there is a lack of in-depth understanding of the change rule of temperature, fluid production in each section and cluster and stimulation parameters under the conditions of different production regimes in horizontal wells with different well body structures.

In this study, by conducting continuous tubing through fiber-optic fluid production profile tests on wells A (downslope wells) and B (upslope wells) with different well body structures and DTS/DAS data acquisition for 10mm, 6mm/5mm nozzles and shut-in production regimes, we obtained data on the temperature change and vibration change under the conditions of different production regimes. Then we interpreted and analyzed the monitoring results by applying the temperature and acoustic interpretation model to get the fluid production of each fracturing section cluster under the conditions of different production regimes.

The monitoring results show that the overall temperature change of the wellbore caused by the production adjustment of 10mm/6m/5mm nozzle is small, and the temperature change caused by the adjustment of the production regime of shut-in/opening the well is large, and the whole wellbore warms up/cools down significantly. The vibration response of DAS in the area of the main production layer is obvious, and the vibration signal has obvious intensity change in the process of regime switching, and the production signal stops after shutting in the well. The toe temperature of downslope wells is higher than the heel temperature, the wellbore temperature of the heel increases after the toe produces fluids, and the larger the nozzle is, the more obvious the heel warming is; the toe temperature of upslope wells is lower than the heel temperature, the wellbore temperature of the heel decreases after the toe produces fluids, and the larger the nozzle is, the more obvious the heel cooling is. There is a certain positive correlation between fluid production and injected fluid volume/pumped sand volume, and the correlation between fluid production and injected fluid volume is stronger for small nozzles. Increasing the production differential pressure of downslope wells can increase the effective mobilization of toe, and increasing the production differential pressure of upslope wells is difficult to increase the effective mobilization of toe, which can be improved by increasing the modification strength of toe.

This study was the first time to find out the temperature change rule of horizontal section of different well body structures and the relationship between production capacity and stimulation parameters based on DTS/DAS, which provided a reference for the formulation of the subsequent development plan of the oilfield and the optimization of stimulation measures.