Calculation and Full-Size Experimental Research on Performance of Titanium Alloy Screen Pipe under the Thermal Recovery Condition

Stem from high specific strength, low density, low elastic modulus, excellent mechanical properties, high temperature resistance and corrosion resistance, titanium alloy has become a promising candidate material to solve the high casing damage rate under heavy oil thermal recovery conditions. However, the study of titanium alloy slotted screens under thermal recovery conditions is still lacking. In this paper, the physical and chemical properties, axial thermal deformation, axial thermal stress, the change law of screen and slot shape of titanium alloy screen pipe under typical working conditions of heavy oil thermal recovery in Liaohe Oilfield were investigated by finite element assistance (FEA) calculation and full-size test. The results show that titanium alloy screen has good strength and toughness properties under thermal recovery condition, and the thermal stress of titanium alloy screen under 350 degrees C thermal recovery temperature is only 19.3% and 20.4% of those of CMS screen and composite screen. After seven cycles of thermal recovery temperature, the axial elongation of titanium alloy screen at 350 degrees C is only 58.7%similar to 60.4% of that of steel screen. Under the large bending degree of 20 degrees/30 m and the high temperature of 350 degrees C, the titanium alloy screen has excellent deformation resistance, the maximum ovality is only 4.13%, the parallel slit remains intact and the sand control ability is better than that of the steel screen of the same specification. Based on this study, it can be considered that the titanium alloy screen and casing can effectively reduce the axial thermal stress and elongation of the thermal recovery pipe string under the thermal recovery condition, have high temperature resistance and fatigue resistance, and have good deformation resistance under the extreme bending condition of thermal recovery, which is one of the effective methods and development directions to solve the problem of high casing damage rate in heavy oil thermal recovery field in China, this study also provides technical reference for the design, use and management of titanium alloy screen.