Risk Assessment Study Of Offshore Ground Test Process

Testing is the most direct and accurate way to assess the consistency of oilfield,monitoring,and other data;wellhead pressure,temperature,oil and gas ratio,steady production,composition of formation fluid,compression coefficient,and other data can all be recorded using surface testing equipment;as a result,testing is vital for the efficacy and protection of oil and gas field growth.There is currently no formal risk evaluation of the offshore surface testing process and the related safety mechanism in China,and there are few reports on the risk identification of major injuries and the safety system in offshore surface testing operations.The offshore ground test process system is the research object of this paper,which uses theoretical analysis and Ansys finite element software to investigate each major risk point in the offshore ground test process system,establishes the offshore ground test process system's accident tree model and Bayesian network,and examines the boundary conditions,limit working conditions,and critical states:(1)Establishment of an offshore ground test phase framework accident tree model:In order to improve the risk identification rate of the offshore surface process system and reduce the process risk factors,the risk factors such as sand content,hydrate,temperature and pressure variation,erosion,vibration and thermal radiation need to be sorted out systematically,and the probability of occurrence of each evaluation index and its interconstraint relationship are analyzed by accident tree analysis and hierarchical analysis.A risk assessment system was constructed for the offshore ground test process,and a Bayesian network model was formed.(2)A study of surface process pipeline erosion was conducted: Based on the field ground test process bend data,Ansys-Fluent geometry model and erosion model were established;based on the results of pipeline erosion risk analysis in the accident tree model,the simulation calculation of bend erosion with different solid particle diameters,different solid phase particle contents and different flow velocities was carried out,and the erosion analysis under the coupling of flow velocity and solid phase particle contents was completed.(3)Ground process pipeline vibration was investigated: The nonlinear fluidstructure coupled vibration equation of the ground process straight line and the fluidstructure coupled vibration equation of the ground process straight line under pressure shock excitation are analyzed,and the inherent frequencies of the ground process straight line,bend and reducer in different forms are simulated;the dynamic response of the bend is analyzed under different bend radii and different discharge pressure fluctuations,and the stress,deformation and acceleration of the bend are obtained.The stress,deformation and acceleration of the bend are obtained.(4)Surface process hydrates and thermal radiation were studied: The temperature and pressure distribution during the passage of high-pressure liquid through the nozzle was analyzed using Ansys-Fluent,and the pressure,temperature and velocity clouds at the nozzle needle valve for different pressure inlet cases were obtained to predict the region of gas hydrate generation.Ansys analysis software was used to obtain the trends of radiation volume and radiation temperature range generated by the jet flame for different pipe diameters of the same production rate and for different production rates of the same pipe diameter.(5)Establishing an offshore ground process system risk system: In view of the above risk point analysis and combined with relevant standards to classify the risk level of risk factors,establish the tracking and management mechanism of major risk factors,put forward the preventive measures of major risk factors,and effectively avoid the losses caused by major risk factors.