Research and test of a horizontal well casing dropping control unit

Compared with vertical wells, horizontal well fishing operations are more difficult, high cost and taking the risk of well abandoned. For this case, high-intensity dropping control unit for horizontal wells in ultra-low permeability reservoirs was developed, which is specific suitable for horizontal well structure. The device structure, technique principle and technical features of this unit were introduced in this paper, and then the anchoring strength was theoretical calculated and performance index was studied in lab tests. Theoretical calculation and repeated laboratory and field tests show that the device has a good adaptability to the downhole and anchor effect, which can basically meet the production requirement of horizontal wells in ultra-low permeability reservoirs. The device has a feasible principle, logical structure, reliable performance and could be widely applied.