Research On Cuttings Transport With Foam Drilling Fluid

Underbalanced drilling technology is developed rapidly in recent years.It refers to that the pressure of mud fluid column is lower than the underlying pore pressure in the process of drilling,and it is usually applied in the reservoir which is easy to leak,much sensitive to water,and has low pressure,and energy exhaust quickly and natural gas reservoir and coalbed methane reservoir.The foam drilling technology is an important branch of underbalanced drilling technology.Compared with the traditional drilling fluid,foam drilling fluid characterizes in low density,easy tuning,small amount of fluid loss,high cuttings carrying ability,low corrosion,strong salt resistance and good stability.The cycle medium in the process of circulation of foam drilling is foam.Compared with the traditional drilling,the velocity distribution,flow characteristics,carrying rock ability and so on during the annulus have very big difference.At present there is not yet systematic experimental study and a mature systematic theory hasn't been reported on it.In this paper,the flow pattern and cuttings transport properties in the circulation process are studied through the theoretical research combined with experimental research in order to better application of foam drilling in practice.In this study,first of all,cuttings transport with foam drilling fluid is analyzed in theory,and then experimental equipment of cuttings transport in annulus is used to study different factors on the efficiency of cuttings transport with foam.And noted and calculated the experimental data.and took the comparison with academic value and they tallied well with each other.The successful combination of theoretical analysis and experimental study improves the theory of the cuttings transport with foam to a great extent,and promote the use of foam drilling technology.