This text introduced the practice method of the box permanent steel petroleum derrick shaft sinking in the construction of vertical shaft pit shaft.
What's the safe working load of each derrick?
The opening hatch cover method also not to be satisfied that using the warping head of cargo gear not through derrick boom open the hatch cover because using derrick boom is not safe.
What's more, it can deal with and analyze the experimental data gotten and finally achieve the capability parameters of marine workover rigs derrick.
Results show that in view of safety and economy design of the derrick and it's lifting installation are reliable.
The pylon cell units were hoisted to the deck by the transfer derrick.
Study of forecasting the bearing capacity of drill derrick based on dynamic parameters;
Four fixed rings need to be added on upper deck for derrick holds.
The fixed set of pulleys (called sheaves) located at the top of the derrick or mast, over which the drilling line is threaded.
The actual wellbore length from the kelly bushing (KB), derrick floor (DF), foundation or ground level (GL), to a point in the well or bottom of the well.
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