Abstract
Sand control in an open hole typically results in risky completions, especially in weak or unconsolidated formations. Stand-alone screen completions present the risk of wellbore collapse and screen erosion, while gravel packing involves time-consuming and complicated pumping operations. Although expandable sand screens have recently become available to provide the best of both worlds, fast installation and wellbore support, design constraints limit their application. Wellbore conformance, expansion loads, and connection integrity have been critical issues with these types of screens. Where successful applications have been found, improved production with lowered drawdown have been typical.
Extensive research and finite element analysis have led to the development of bistable expansion cells. These cells have minimal plastic deformation during expansion and exhibit a hysteresis -like behavior. The specific cut pattern can open with relatively low expansion force, and then resist higher-level collapse loads. Due to the low plastic strain levels, bistable cells are compatible with any common oilfield material, achieving expansion ratios as high as 1.6 times the original screen diameter. This paper will cover the design, development, and testing of an expandable sand screen using bistable cell technology. In addition, the design and development of the proprietary expandable connection will be presented. The testing presented covers a wide range of structural integrity, expansion, sand retention, mudflow, and geomechanical tests performed on the screen, base pipe, and connection.
In late 2002, the first bistable expandable sand screen was deployed in a 4,400-ft water injection well in west Texas. The compliant expansion tool deployed the screen in one trip at speeds exceeding 1,800 feet per hour with set-down loads of less than 20,000 pounds.
