engleski

How to drill and achieve primary cementing under blowout condition and loss of circulation

Since the carbonate sediments in the Dinaric Alps are characterised by the hydrogeological phenomena described and technical problems, on the basis of the acquired experience, the following technical principles for further realisation of Dinaric wells have been adopted: a)The first (introductory) acsing string must be cemented from shoe to well head in such a way that regardless of the loss of circulation a 100 % stability and hermeticism is achieved. b)In the continuation of drilling sea water should be used for rinsing by the application of the best technique of rinsing regardless of a complete or partial loss of circulation. c)When caverns and fractures are met, drilling should be performed without circulation, and caverns should only be closed if technical reasons require their closing e. g.: excessive settling of rock particles on the well bottom, the sticking of the drill stem, possible fractures of tools, increased caution because of the expected discovery of deeper carrier rocks etc. d) If non-consolidated rocks layers are discovered it is esential to consolidate these non-consolidated zones completely before resuming drilling. e) To perform cementing of the casing string which will ensure the maximum possible pumping of the cement slurry into the annulus.

Technical solutions; well bowouts; primary cementing

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