Design and Simulation of New Unit Earth Anchor for Pre-stressed Cementing

摘要

During prestressed cementing for heavy oil thermal recovery wells, it is encountered that the earth anchor connecting to the bottom of the casing string anchors difficultly, and anchoring force can not meet design requirement. A new type of unit and resettable earth anchor structure for prestressed cementing is introduced. The project can use multiple unit combination according to different formation condition and can choose different length of the earth anchor fluke according to diameter of the well. ANSYS/LS-DYNA is used to simulate the process of the fluke digging into the wall of the borehole with different diameter. Variation of reaction force of rock upon the fluke with different initial digging angle is analyzed, and the most favorable angle range in which the fluke digs into the borehole wall is concluded. A favorable reference to determining fluke's geometric parameter and selecting type of the claw is provided.