Well drilling overflow control method and system

Abstract

The invention provides a well drilling overflow control method and system. The well drilling overflow control method comprises the following steps of applying back pressure to a drilled wellhead; obtaining the increased speed of the well bottom overflow quantity or the descent speed of the well bottom pressure after applying the back pressure to the drilled wellhead; judging the overflow type according to the increased speed of the well bottom overflow quantity or the descent speed of the well bottom pressure; when the overflow type is underbalance overflow, obtaining the well drilling parameter; according to the well drilling parameter, calculating the maximum allowable initial overflow quantity; according to the maximum allowable initial overflow quantity, the initial well bottom overflow quantity, the well bottom overflow quantity within the lagged time and the wellhead pressure, selecting the well drilling overflow control manner to control the well drilling overflow; and when theoverflow type is gravity displacement overflow, according to the initial well bottom overflow quantity, the well bottom overflow quantity within the lagged time and the wellhead pressure, selecting the well drilling overflow control manner to control the well drilling overflow. With the adoption of the well drilling overflow control method, the well drilling overflow can be effectively controlledto gain time for overflow control.

Description

technical field [0001] The invention relates to the technical field of drilling engineering, in particular to a drilling overflow control method and system. Background technique [0002] Overflow is one of the most common downhole complex accidents that affect drilling safety. Overflow will not only increase the investment cost of exploration and development, resulting in low efficiency of oil and gas development, but also cause major vicious accidents such as pipe sticking and blowout if the control is not effective. In recent years, with the development and application of precise MPD technology, the overflow and leakage caused by conventional technology "unpredictable" and "uncontrollable" have been improved. Therefore, it is of great significance to study the overflow control method based on fine pressure control. [0003] Existing technologies and methods mostly focus on the monitoring and identification of overflow, and cannot effectively control the overflow of drill...

AI Technical Summary

Problems solved by technology

[0003] Existing technologies and methods mostly focus on the monitoring and identification of overflow, and cannot effectively control the overflow of drilling

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