Software Simulation and System Design of Dynamic Killing Technique

摘要

Uncontrolled eruption of a well is one of the most critical accidents that can occur in the exploration and exploitation of hydrocarbon fields. Several well control methods have been developed to bring blowout wells under control as quickly as possible. The dynamic killing technique is typically adopted when a relief well needs to control the event. The method calls for bringing the blowout well under control by pumping water (or brine) at a flowrate sufficient to exceed the formation pressure of the blowing well. This phenomenon occurs through a combination of kill fluid static head and frictional pressure losses of kill fluid in the blowout well. Dynamic killing is constituted by a complex multi-phase fluid dynamic system with a complex geometry: blowing well, relief well and reservoir. An advanced model able to simulate the killing phenomenon during all its transients is necessary for applicability screening and system design.A software has been developed under an HSE R&D project and implemented by an integrated work team made up of the safety, production, drilling and reservoir engineering departments of oil and service companies. The dynamic killing software, by simulating the killing transient with a series of loops through submodels, correlates killing flowrate, breakthrough and killing time, relief bottom hole pressure and required killing pump head and power as outputs. This model is able to simulate the dynamic killing of an atmospheric or underwater blowout event. It is also able to analyze the in-string killing disabling the reservoir submodel. This paper fully describes the dynamic killing model in terms of both subroutines (blowing well, relief well and reservoir models) and software applications (method applicability, system design, main killing parameters).In addition, the results of software validation simulating dynamic killing cases in the field are reported. This analysis indicates good accuracy of the model in terms of transient duration and killing requirements.