Numerical Simulation of Large-Diameter Annular Pressure Loss in Riser Segment of Deep-Water Drilling
Large-diameter annulus and conventional annulus are very different in hydraulic property. Based on numerical simulation, a study on pressure loss of large-diameter annulus was carried out. The influence of annular velocity, pipes rotation speed, mud property and annular diameter of marine riser segment on pressure loss was also analyzed and compared with that of conventional segment. The results show that under the condition of large-diameter annulus, the pressure loss of power law fluid laminar flow decreases with the increase of the rotational speed of drill pipe and the contrary tendency occurred when it is turbulent flow. With the increase of the flow behavior index and consistency coefficient, annular pressure loss increases exponentially and linearly respectively. From an overall perspective, with the increase of annular size, the annular pressure loss sharply reduced, and it has great effect on pressure loss.