Air-lift reverse circulation drilling technology is often used in geothermal well drilling, but there are many problems along with drilling depth increasing, such as double-wall drill pipe leaking, air-water mixer blo.
[pdf] Reverse circulation is achieved by blowing air down the annulus of the rod, the differential pressure creating air lift of the water and cuttings up the inner tube which is inside each rod. It reaches the deflector.
[pdf] Before starting casing, the drilling supervisor should hold a pre-job safety meeting and confirm the following with the crew: 1. Remove unnecessary tools. 2. Good Housekeeping before the job 3. Rig up Casing handling equipment: Using appropriate hand. .
A circulation sub, fitting the casing thread, equipped with a WECO connection, shall be readily available on the rig floor at all times during casing running.
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