| 摘要 |
<p>A mechanical down jar (10) and method for its use in releasing stuck objects within a well bore and for conducting other downhole servicing operations. The mechanical down jar mechanism (10) incorporates a tubular body having fixed anvils (28, 30) and telescoping mandrels at each end, the lower of which is connected to the stuck object. An internal load spring (60) is released upon application of predetermined downward force to the housing (12) by a firing lug (110) and firing ring (140) release mechanism having an adjustable release force. When released the lower anvil of the housing is rapidly moved downwardly by the force of the load spring (60) and impacts with significant force against the force transmitting sub of the lower mandrel thus transmitting downwardly directed shock force to the stuck object.</p> |
