A gel slug isolation well control method

Abstract

The invention discloses a gel plug packing well control method. The well control method includes the following steps that S1, a gel plug is built in a wellbore when spillage together with complicated wellbore conditions appear; S2, throttling circulating exhaust is performed on packed upper portion of the wellbore; S3, preparatory work for boring stopping and leaking stoppage is performed in safe operation time provided by wellbore packing; S4, the gel plug is broken to remove the wellbore packing, and leaking stoppage operation is performed by the adoption of an extrusion method; S5, weighted drilling fluid is used for throttling well killing. The well control method has the advantages that due to wellbore packing through the gel plug and removal of wellbore packing through gel breaking, a brand new choice is provided for processing the complicated wellbore conditions; the gel plug blocks an oil-gas shifting-up channel, in this way, overflow is effectively controlled to be located in the bottom hole, the safe operation time is provided for leaking stoppage and well killing, and safety risks of well control are reduced; the technical thought is novel, the technical scheme is reliable, and the well control method is beneficial for forming a practical engineering technology.

Description

technical field [0001] The invention relates to the technical field of oil and gas well pressure control (well control), in particular to a gel slug isolation well control method suitable for the complex situation of fractured reservoir overflow and coexistence of wellbore. Background technique [0002] For fractured reservoirs, the existence of holes and fractures makes a good channel between the wellbore and the reservoir. Compared with the traditional well control technology for permeable reservoirs, the fractured reservoir well control There are considerable differences in well control theory, established technical system and other aspects. [0003] Because the fractured reservoir does not meet the seepage conditions, the seepage resistance is very small, resulting in a narrow safe density window: under negative pressure conditions, it is a typical negative pressure continuous overflow (only overflow but not leakage); under positive pressure conditions, it is typical Le...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, provide a gel slug isolation well control method, provide safe operation time for drilling stoppage and plugging (such as deploying mud plugging, tripping drill string, etc.), improve overflow Kill the success rate, reduce the safety risk of well control, and solve the problems of conventional well control technology in the complex wellbore situation where the fractured reservoir overflows and leaks coexist

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