Method and device for early monitoring of wellbore gas kick based on annular pressure measurement while drilling

Abstract

The invention relates to a method and a device both based on annulus pressure measuring while drilling and for early monitoring gas invasion of a wellhole. The device is characterized in that the device comprises a drilling column arranged in the wellhole, the bottom of the drilling column is connected with an annulus pressure measuring while drilling device and a drilling bit, the annulus pressure measuring while drilling device comprises an annulus pressure sensor, an annulus temperature sensor, a signal monitoring circuit, a data storage circuit, a battery and a data connector, the top of the annulus pressure measuring while drilling device is connected with a measuring while drilling device which comprises a signal receiving module and a pulse generator, a drilling fluid returning flowmeter is arranged on the upper portion of the drilling column, one side of a wellhead is connected with a mud pump and a mud circulating pool through a pipeline, a mud pressure sensor is mounted on the mud pump, a mud level meter is arranged in the mud circulating pool, the drilling fluid returning flowmeter, the mud pressure sensor and the mud level meter are in wire connection with a well logging instrument respectively, a filter module and a signal measuring module are arranged in the well logging instrument, and the well logging instrument is connected with a data analyzing and alarming module through a wire. The method and the device can be applied to deepwater oil drilling operations.

Description

technical field [0001] The invention relates to a monitoring method and device, in particular to an early monitoring method and device for wellbore gas invasion based on annular pressure measurement while drilling in deepwater drilling operations. Background technique [0002] Since the consolidated and loose sedimentary layer is often encountered in deepwater drilling, and the window between the drilling fluid pressure gradient and the formation pressure gradient and the formation fracture pressure gradient is narrow, safe and efficient deepwater drilling is one of the key factors for the development and utilization of offshore oil resources. The basic premise. How to detect overflow early and effectively is the key point of deep water well control, otherwise, if a blowout accident occurs, it will cause serious consequences. The working characteristics of marine deepwater floating drilling units also require that a kick monitoring method that is faster than conventional ki...

AI Technical Summary

Problems solved by technology

However, the traditional gas intrusion prediction and alarm response based on changes in mud logging information and other data (such as dc value and drilling fluid properties, etc.) is not accurate and timely enough to meet the requirements

Moreover, the sensitivity of most existing drilling monitoring systems is about 7 barrels (1 cubic meter). Only when this condition is met will an alarm signal be given. However, when the water depth increases, the safety margin of the wellbore will continue to decrease. The minimum is about 1 barrel, so the existing kick monitoring methods are difficult to meet the requirements of special working conditions in deep water

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