Solid tubular expansion in horizontal wells

The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures under normal operations. Simulation work, laboratory tests, and field trials proved the viability of tubular expansion downhole and field engineers have gained enough knowledge in handling this process. However, tubular expansion in open hole of horizontal sections still presents another challenge to researchers and field engineers due to gravity and drag between the seal and the formation. The present work, therefore, presents simulation results of tubular expansion under various field conditions. In this study a typical tubular size of 57.15 mm outer diameter and 6.35 mm wall thickness is used with two different elastomer seals, 5 mm and 7 mm thick placed at equal spacing of 20 cm. It is found that the drawing force increases as the mandrel angle, expansion ratio, and friction coefficient increase. A typical expansion simulation showed that the drawing force required for expansion using a rotating mandrel is 15% less than that of non-rotating mandrel having same configuration. However, tubular thickness reduction is found to increase by 47% for a rotating mandrel as compared to a non-rotating one, which may affect the post-expansion tubular performance. The tubular wall thickness decreases as the mandrel angle, expansion ratio, and friction coefficient increase.