Research on Testing a Prototype of an Expandable Profile Liner in a Directional-Well Section in a High-Fidelity Laboratory Environment

Summary The application of an expandable profile liner (EPL) for leakage plugging in a directional section of deep and ultradeep wells is still at the exploratory stage. In this study, the finite–element software Abaqus (2014) is used to optimize the section of nominal diameter (Φ) 5⅞-in. (149.2-mm) EPL that can meet the plugging and strength requirements. The internal–pressure–limit test, crushing test, overall string–sealing experiment, and mechanical shaping experiment are performed, and the optimal welding procedure is developed. After the hydraulic–expansion and mechanical shaping process, the EPL is found to meet the design size and construction requirements. Simulating the trip-in and the expansion process at different reaming–wellbore diameters, with a comprehensive consideration of the expansion requirements and ensuring that the adhesion force effectively seals the EPL against the wellbore, it is better to set the diameter of the reaming wellbore to 6.889 in. (175 mm) with borehole curvature at 30°/98.42 ft (30°/30 m). Using the curved–steel tube to simulate the borehole curvature at 30°/98.42 ft (30°/30 m) with four different inclination–change and azimuth–change combinations, it is feasible to apply the EPL technology (EPLT) for the directional–well–section–leakage plugging when the inclination change or azimuth change is not too large.