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ORIGINAL RESEARCH article
Front. Earth Sci.
Sec. Georeservoirs
Volume 13 - 2025 | doi: 10.3389/feart.2025.1558305
This article is part of the Research Topic Intelligent Artificial Lift and Multiphase Flow in the Wellbore in the Oil and Gas Production Systems View all articles
Prediction and analysis of flow behavior during gas kick considering wellbore-formation coupling and gas solubility
Provisionally accepted- 1 PetroChina Southwest Oil and Gasfield Company, Chengdu, Sichuan Province, China
- 2 Southwest Petroleum University, Chengdu, China
This paper presents a novel transient flow model for gas kick by taking wellboreformation coupling and gas solubility into account during drilling operation. Then, the main flow parameters such as gas void fraction, mixture velocity and mixture density are analyzed for cases with or without considering the coupling effects. Furthermore, the flow behaviors for both OBM and water-based muds (WBM) are investigated for comparison. Finally, the reliable indicators of monitoring gas kick in OBM and WBM drilling are discussed. The results show that the gas void fraction increases after an initial decrease with the increased wellbore depth with coupling effects, while it constantly decreases with the increase of the well depth with non-coupling effects. The variation of bottomhole pressure (BHP) with gas kick time is similar in two cases. Both the mixture velocity and mixture density change more significantly in the middle-lower part of the wellbore compared with non-coupling effects. In particular, the performances of surface response to a gas kick are quite different compared to the WBM under similar conditions in OBM drilling and the potentially dangerous gas kick is easy to be neglected. More importantly, it is confirmed that pit gain is more beneficial for detecting gas kick compared with the annulus return flow rate (ARFR) for WBM, but neither of these indicators is suitable for gas kick detection in OBM drilling. The results identify pit gain as a reliable indicator for detecting gas kick in WBM drilling, while real-time bottomhole pressure (BHP) monitoring is emphasized for OBM drilling under low influx rates.The results can provide guidance for controlling the wellbore pressure in WBM drilling and new ideas for detecting gas kick in OBM drilling.
Keywords: gas kick, Drilling operation, Flow behavior, Gas solubility, wellbore-formation coupling, Gas kick detection
Received: 10 Jan 2025; Accepted: 17 Mar 2025.
Copyright: © 2025 Su, Ma, Xia, Peng, Guo, Shen, Fu and Tang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Chi Peng, Southwest Petroleum University, Chengdu, China
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