Shale gas well blowout fire and explosion modelling

Abstract

This paper presents the development and application of a multi-phase CFD flow model for predicting the thermal radiation and explosion over-pressure in the event of an accidental well blowout during shale gas production. The transient discharge rate and the fluid phase composition at the ruptured wellhead serving as the source term are determined based on the numerical solution of the conservation equations using the Method of Characteristics. Two scenarios covering immediate and delayed ignition of the escaping gas respectively leading to a jet fire or an explosion are considered. In the former case, the flow model's output, including the transient flow rate, fluid phase and composition, is linked to the widely used Chamberlain semi-empirical jet fire model to generate the resulting flame area and incident heat flux. In the case of a delayed ignition leading to an explosion, the TNO Multi-Energy Vapour Cloud Explosion is linked to the flow model to predict the resulting blast overpressure for both un-confined and partially confined explosions. The blowout model is tested by simulating the accidental well-head rupture of a real shale gas production well for which the required design, operational and prevailing ambient data are publicly available. The simulation results are presented in the form of 2D plots of thermal radiation contours as a function of distance and time and explosion overpressure/distance profiles; in turn employed to determine minimum safe distances to personnel and equipment.

Risk assessment of offshore fire accidents caused by subsea gas release

“…The ambient temperature is 21.4 • C, and the relative humidity is 60%. The gas release rate of a shallow gas blowout can be calculated through the theoretical model (Buaprommart et al, 2019). This study uses the assumed gas flow rate based on previous publications and accident reports and takes multiple gas release rates to explore its effect on offshore fires.…”

Structural Response Analysis of FPSO under Pool Fire

“…Although this platform has many advantages, the high level of congestion caused by pipe networks and upper crude oil processing equipment poses a higher risk to the FPSO [4][5][6]. As the offshore platform or FPSO are far from the land, once fire and explosion accidents occur, it is difficult to conduct a timely rescue, which results in disastrous loss [7].…”