Research On The Horizontal Well Hydraulics Of Jet PDC Bit

Horizontal drilling technology is one of the important technologies in the modern oil industry because of the unique advantage. Horizontal drilling, compared with vertical well drilling,has it's own characteristics.When horizontal drilling, debris are in the direct impact of the migration to the below of the wall under the influence of gravity. Reasonable flow field can improve the portable rock effect in the bottom and prevent mine accidents, so the study of PDC bit's bottom hole horizontal well flow is very necessary, because it can improve the effect of horizontal well drilling.In this paper, I use Pro / E software to create a PDC bit of three-dimensional model, then use the software GAMBIT to mesh the three-dimensional model and research it in the bottom horizontal well hydraulics with the FLUENT software. Analysis of the PDC bit in horizontal well drilling process and drill to the bottom of rotating flow under the gravity when the flow field flow; analysis the trajectory of the debris in the bottom; analysis the each nozzle hydraulics situation; analysis the debris at the bottom of the role of horizontal, which movement are cleaned from the flow field of the bottom hole; analysis the result of the flow field that how to weaken, delay the cuttings bed Chip. By changing the nozzle inlet pressure, drill gage width, nozzle diameter factors, to study the changes in these flow fields.Through the study we found that the debris in the bottom have the trend to deposition to the wall below by the gravity when they movement to the ground; the high-speed flow of drilling fluid in the bottom was little affected by the gravity.The overflow tank level and the speed of both the role of Chip can be changed by changing the factors such as the nozzle inlet pressure, drill gage width, nozzle diameter of the PDC bit. Study the fluid jet injection angle and the distance from the center drill, drill on cleaning the bottom and the surface of the debris along the wall direction back to all have an effect. To the PDC drill bits for the horizontal well hydraulics, there are two proposed improvement program to ensure bottom flow field.With the borehole at the bottom of the effect, the increase of one chip removal rate of fluid flow, can be achieved to prevent debris deposition, slow down production and remove cuttings bed purpose of cuttings bed. The results of the research have the important reference and guidance effect to design the hydraulic structure of the PDC bit that using in drilling horizontal well.