A plugging method for oil and gas wells

Abstract

The present invention provides a method for plugging leaks for oil and gas wells, which includes the following steps: detecting the oil and gas wells and determining the position and length of the lost well section; The drill pipe and the lost circulation drilling tool are run into the lost circulation drilling tool until the bottom of the lost well section; the cement slurry is injected through the drill pipe and the lost circulation drilling tool until the slurry replacement is completed. The drill pipe is pulled out; the drill bit is drilled to remove the cement plug and the plugging drilling tool solidified in the cement slurry, so as to be able to carry out the subsequent drilling construction, so as to complete the plugging construction of the lost well section; wherein, the The drill pipe and the plugging drill are assembled and connected by disconnecting joints. During the process of pulling out the drill pipe, the drill pipe is pulled until the disconnected joint is broken, so as to be connected with the solidified cement slurry. The plugging drilling tool in the device is disconnected, thereby pulling out the drill pipe.

Description

technical field [0001] The invention relates to the technical field of drilling engineering of oil and gas wells, in particular to a plugging method for oil and gas wells. Background technique [0002] With the continuous development of oil and gas exploration projects to deep formations, the structure of drilling formations is becoming more and more complex. For example, there are problems such as fault development, formation fragmentation, fracture and pore development in deep formations, which may lead to loss of drilling fluid during drilling. Traditional drilling methods have many types of lost circulation, many lost horizons, high occurrence rates, and difficult governance. These will not only seriously endanger the safety of drilling operations, but also greatly interfere with normal drilling and affect production progress. Seriously It will also cause a series of complicated situations such as drilling sticking, blowout, well collapse, etc., and even lead to the scr...

AI Technical Summary

Problems solved by technology

However, there are still some problems in the existing bare drill pipe grouting plugging

For example, when the cement slurry solidifies for a long time, the cement slurry enters the formation and then enters the formation along the leakage channel, which cannot form an effective protective layer in the fracture and wellbore, and its plugging effect is poor, and the leakage layer cannot be effectively sealed

When the cement slurry solidifies for a short time, it is very easy to cause the drill pipe to solidify in the cement slurry, resulting in the occurrence of "flag pole" accidents, which complicates the downhole situation and further aggravates the difficulty of plugging the lost well section

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