| Multilateral well was once reputed to be one of the eight new drilling techniques by oil international experts, in which there are one well-head and more than one underground bore-hole. About 720 multilateral wells had been built from 2001 to 2011 by Harlliborton Incorporated, most of which is TAML 4 or 5. More than 10000 casing cutting operations have been completed by Weatherford Incorporated. According to the difficulty multilateral well is classified into 6 types, in which TAML 4 is used the most widely.The deep, hard to exploit reserve is above 40 percent in Liaohe oil field. The TAML 4 multilateral well is needed to enhance single well controlled reserve and production to reduce marginal development cost. The are many difficulties for regular multilateral well technique in this formation, for example long window cutting period, heavy whip-stock retrieving hook load, high pressure for hydraulic tool and so on.Hard formation casing cutting tools are developed in this text. New milling material and welding method are used to solve the difficulty of low milling speed and little footage for one miller. Concave whip-stock, anti-cutting tool, new whip-stock fishing tool and so on are designed and used. Ground test and field application have shown more than 3 times milling speed and below half window cutting period than before.Whip-stock seat, releasing tool, and so on multilateral completion tools suited for 75MPa pressure are developed in this text. Solidworks software is used for design and analysis. And than lots of ground tests are implemented to check out the design and choose the best roughness and sealing method. The tools were proven reliable in a 75MPa well. |
