Retrieval Tool With Slips for Retrieving Bottom Hole Assembly During Casing While Drilling Operations

An apparatus for casing-while-drilling operations, comprising:

• a bottom hole assembly for releasable connection with a casing string;
• a retrieval tool adapted to be run into the casing string and moved downward into contact with the bottom hole assembly;
• a latching device mounted to the retrieval tool for engagement with the bottom hole assembly, defining a retrievable unit comprising the retrieval tool and the bottom hole assembly;
• a set of slips mounted to the retrieval tool for movement from a retracted position during running in to an engaged position during upward movement of the retrievable unit, the slips adapted to engage the casing string while in the engaged position so as to prevent downward movement of the retrieval tool but allow upward movement of the retrieval tool in the casing string;
• a flow passage extending through the retrieval tool and the bottom hole assembly;
• and
• a check valve in the retrievable unit that allows downward flow through the flow passage but prevents upward flow, so that fluid may be circulated through the retrievable unit while suspended with the slips.

A retrieval apparatus for retrieving a bottom hole assembly during casing-while-drilling, comprising:

• a body having a flow passage therethrough;
• a seal assembly mounted and protruding outward from the body;
• a plug member in the flow passage having a blocking position that blocks downward flow through the flow passage, enabling the body to be pumped down the casing string into engagement with the bottom hole assembly, the plug member being movable to an open position in response to fluid pressure applied to the casing string after engaging the bottom hole assembly;
• a gripping member mounted to the body for gripping engagement with the bottom hole assembly;
• the body being upwardly movable in the casing string, along with the bottom hole assembly in response to a pressure differential;
• a set of slips mounted to the body for movement from a retracted position during running in to an engaged position during upward movement of the body, the slips adapted to engage the casing string while in the engaged position so as to prevent downward movement of the body but allow upward movement of the body in the casing string;
• and
• a check valve in the body that allows downward flow through the flow passage after the plug is in the lower position but prevents upward flow, so that fluid may be circulated downward through the body while suspended with the slips.