| 摘要 |
A whipstock (100) is attached to a cutting tool (120) by a shearable connection (405, 410) whereby the whipstock and cutting tool assembly may be run into the wellbore simultaneously. Upon compressive force from above, the shearable connection fails and the cutting action can begin. The shearable connection (405, 410) is designed to fail in compression but to withstand forces in tension brought about by the whipstock, accessories and extensions required to properly place the whipstock above a preset packer in the wellbore. In one aspect, the shearable connection means provides a first set of shearable members (410) with equal shear resistance in tension and in compression. Another set of shearable members (405) provide shear resistance against tensile forces but do not provide shear resistance against compressi ve forces. Failure of the connection due to the weight of the whipstock assembl y is less likely.
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