热采井筒高压条件下过热水膨胀蒸汽爆炸试验研究

In light of the frequent accidents occurring in Steam-Assisted Gravity Drainage (SAGD) wells, a physical explosion experimental system for superheated water steam was designed and constructed. This system simulates and investigates pressure variations during Boiling Liquid Expansion Vapor Explosions (BLEVE) of superheated water under high-temperature and high-pressure conditions within the wellbore. The study explores the effects and causes of initial pressure, release diameter, and initial temperature on the maximum rebound pressure peak within the container, utilizing rupture disk nominal pressure, design diameter, and steam heating temperature as key parameters. The initial pressure was set at 3 MPa, 4 MPa, and 5 MPa, while the release diameters were configured at 3 mm, 10 mm, and 15 mm, and the initial temperatures were established at 180 ℃, 200 ℃, and 220 ℃. Utilizing the experimental data, the tensile load generated by physical explosions at the casing head during superheating was calculated, and the variation patterns of this tensile load were analyzed alongside corresponding preventive measures. The results indicate that the maximum rebound pressure peak is approximately 1 to 4 times the initial pressure. Under constant conditions for the other two variables, increases in initial pressure, initial temperature, and release diameter lead to higher maximum rebound pressure peaks. The experimental data were utilized to calculate the tensile load generated by a BLEVE during an instantaneous release within the wellbore. It was found that under conditions of an initial pressure of 5 MPa, an initial temperature of 180 ℃, and a release diameter of 10 mm, the minimum maximum force recorded was 124 kN. In contrast, under an initial pressure of 5 MPa, an initial temperature of 220 ℃, and a release diameter of 15 mm, the maximum force reached 598 kN. Based on these findings, several recommendations were proposed for the SAGD process to prevent BLEVE occurrences or to mitigate potential damage to production operations. Future research will focus on developing BLEVE suppression structures and conducting coupled analyses involving multiple parameters.