Numerical Simulation of Water and Sand Blowouts When Penetrating Through Shallow Water Flow Formations in Deep Water Drilling  

作　　者：REN Shaoran LIU Yanmin GONG Zhiwu YUAN Yujie YU Lu WANG Yanyong XU Yan DENG Junyu 

机构地区：[1]School of Petroleum Engineering, ChinaUniversity of Petroleum (East China) [2]Department of Petroleum Engineering, Curtin University [3]Research Institute of Engineering Technology, ChinaNational Petroleum Corporation

出　　处：《Journal of Ocean University of China》2018年第1期17-24,共8页中国海洋大学学报（英文版）

基　　金：Financial supports by the 973 National Research Project of China (No. 2015CB251201);the program for Changjiang Scholars and Innovative Research Team in University (‘PCSIRT’) (IRT_14R58);the Fundamental Research Funds for the Central Universities (No. 15CX0 5036A)

摘　　要：In this study, we applied a two-phase flow model to simulate water and sand blowout processes when penetrating shallow water flow(SWF) formations during deepwater drilling. We define ‘sand' as a pseudo-component with high density and viscosity, which can begin to flow with water when a critical pressure difference is attained. We calculated the water and sand blowout rates and analyzed the influencing factors from them, including overpressure of the SWF formation, as well as its zone size, porosity and permeability, and drilling speed(penetration rate). The obtained data can be used for the quantitative assessment of the potential severity of SWF hazards. The results indicate that overpressure of the SWF formation and its zone size have significant effects on SWF blowout. A 10% increase in the SWF formation overpressure can result in a more than 90% increase in the cumulative water blowout and a 150% increase in the sand blowout when a typical SWF sediment is drilled. Along with the conventional methods of well flow and pressure control, chemical plugging, and the application of multi-layer casing, water and sand blowouts can be effectively reduced by increasing the penetration rate. As such, increasing the penetration rate can be a useful measure for controlling SWF hazards during deepwater drilling.In this study, we applied a two-phase flow model to simulate water and sand blowout processes when penetrating shallow water flow(SWF) formations during deepwater drilling. We define ‘sand' as a pseudo-component with high density and viscosity, which can begin to flow with water when a critical pressure difference is attained. We calculated the water and sand blowout rates and analyzed the influencing factors from them, including overpressure of the SWF formation, as well as its zone size, porosity and permeability, and drilling speed(penetration rate). The obtained data can be used for the quantitative assessment of the potential severity of SWF hazards. The results indicate that overpressure of the SWF formation and its zone size have significant effects on SWF blowout. A 10% increase in the SWF formation overpressure can result in a more than 90% increase in the cumulative water blowout and a 150% increase in the sand blowout when a typical SWF sediment is drilled. Along with the conventional methods of well flow and pressure control, chemical plugging, and the application of multi-layer casing, water and sand blowouts can be effectively reduced by increasing the penetration rate. As such, increasing the penetration rate can be a useful measure for controlling SWF hazards during deepwater drilling.

关 键 词：shallow WATER flow(SWF) deepwater DRILLING WATER BLOWOUT SWF hazards FLOW simulation 

分 类 号：P7[天文地球—海洋科学]