Journal Article

Wellbore Flow Behavior and Natural Flow Cessation Prediction in Ultra‐Deep Wells: A Case Study of Shunbei Oilfield

Gao, Lirong, Luo, Chengcheng, Peng, Zhenhua, Liu, Yonghui, Li, Su

2025

Overview

With continuous attenuation of reservoir pressure, an increasing number of self‐flowing wells in deep and ultra‐deep reservoirs will face flow cessation. Accurately predicting wellbore pressure drop and bottom‐hole flow pressure is key to determining flow cessation time. Existing commonly used pressure models in engineering exhibit poor prediction performance due to the limitation of high‐temperature and high‐pressure conditions in deep and ultra‐deep wellbores. This study first considers the effect of wellbore temperature and pressure on fluid properties, and corrects the crude oil high‐pressure physical parameters based on the measured results of high‐pressure PVT parameter. Second, a new liquid holdup model is established by fitting the fluid holdup derived from the back‐calculation of actual temperature and pressure from production wells. The new model is validated by an example well in Shunbei Oilfield to be significantly superior to other commonly used engineering models in predicting wellbore flow pressure. Finally, a prediction method for self‐flowing well cessation is established using nodal system analysis. Further validation using wells that experienced natural flow cessation in Shunbei Oilfield confirms < 3% error in predicting cessation reservoir pressure. This study develops a framework for predicting flow cessation in ultra‐deep wells, featuring a crude oil property correction model accounting for ultrahigh pressure/temperature effects, a revised liquid holdup model with field‐fitted coefficients, and an integrated pressure drop model coupled with nodal analysis to link reservoir inflow and wellbore outflow dynamics. These innovations address the limitations of conventional methods in ultra‐deep well conditions, enabling accurate flow cessation prediction.

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Crude oil / Deep wells / Density / Dimensional analysis / Flow velocity / Flowing wells / Liquid hold up / liquid holdup / Machine learning / Methods / Natural flow / natural flow cessation / nodal system analysis / Oil and gas fields / Oil field equipment / Oil fields / Oil wells / Parameters / Physical properties / Predictions / Pressure drop / Reservoirs / Reynolds number / Simulation / Systems analysis / Temperature / Trends / ultra‐deep natural flow well / Viscosity / Well drilling / wellbore pressure drop