Abstract：
With the continuous increase in global energy demand, offshore oil & gas resources, especially deep-water oil & gas
resources, have become new development hotspots. The deep-water oil & gas resources are characterized by high reserves, great
potential and low exploration rates, but they are also accompanied by shallow geological hazards and other problems that onshore
drilling works have never faced. Shallow water flow (SWF) is a common geological hazard, which is essentially the over-pres
sured sand section developed in the deep water and shallow areas and mainly formed by rapid deposition and unbalanced
compaction in the formation. SWF hazards have large destructive power and wide distribution areas, which have influence on
the borehole, casing and wellhead, and can seriously damage the integrity of the wellbore. In this paper, the concept, harm, and
main causes of SWF hazards are firstly expounded. Then the identification and prediction technology, risk assessment methods,
prevention, and control measures of SWF hazards are summarized. Finally, risk assessment and comprehensive prevention
methods are put forward. It is concluded that the identification and prediction methods of SWF hazards mainly include logging
and reflection seismic methods. Among these, the reflection seismic method is adopted more commonly in practice, which recog
nizes the overpressure sand body by the abnormal fluctuations of the value of
V
p
/
V
s
. At present, the risk assessment of the SWF
hazards places more emphasis on the pre-drilling prediction and qualitative judgment but lacks quantitative analyses. However,
experimental and numerical simulation studies have been constantly filling this gap in recent years. The prevention and control
operations of SWF hazards include well control measures and working fluid system optimization. Based on current work of the
risk prediction and assessment of the SWF hazards, a new risk assessment system is proposed and then combined with disaster
prevention measures in this study, proposing a dynamic hazard prevention method. This hazard prevention method reasonably
plans the drilling operations in SWF areas, combines the risk assessment scheme with the response mechanism, and continuously
optimizes the drilling scheme during the drilling operation to improve the flexibility of drilling operations and enhances the
hazard prevention ability. Finally, the development trends of SWF hazard prevention are examined. It is considered that basic
research into the flow failure mechanism of the SWF hazards, the development of geophysical identification technology, as well
as the application of artificial intelligence technology (AIT) will be the research emphases in the future.
