Gas invasion early monitoring device and method in drilling process

Abstract

The invention belongs to the technical field of oil drilling, and particularly relates to a gas invasion early monitoring device and method in the drilling process. The gas invasion early monitoring device in the drilling process comprises an underground monitoring device and a ground monitoring device. The underground monitoring device conducts real-time measurement and analog-to-digital conversion on the acoustic attenuation data, the temperature data and the pressure data of mineshaft annulus fluid. Then the data are sent to the ground monitoring device, and the ground monitoring device is used for analyzing and processing the monitored data, and conducting early warning and alarming. According to the gas invasion early monitoring device and method in the drilling process, whether an underground annulus is invaded by stratum gases or not is monitored in real time, and the characteristic of being sensitive in responding is achieved; the stratum gas invasion amount of the annulus at the underground measuring short section is calculated in real time through the data set which is uploaded to a ground data analysis module in real time, so that the invasion amount of the stratum gases is calculated in an accumulative mode; whether the stratum gases invade or not can be accurately judged at the gas invasion stage, and early warning is conducted in advance; the gas invasion amount is acquired through calculation, and data support is provided for preparation of killing well materials.

Description

technical field [0001] The invention belongs to the technical field of petroleum drilling, and in particular relates to an early monitoring device and method for gas intrusion during drilling, which are used to monitor whether there is formation gas intrusion in the annulus of a wellbore and prevent the occurrence of blowout accidents. Background technique [0002] During the drilling process, when the formation pore pressure is greater than the bottom hole pressure, the natural gas in the formation pores will invade the well, which is called gas invasion. If a large amount of natural gas in the formation invades the wellbore and ejects out of the ground, it is called a gas-invasion blowout. The gas-invasion blowout has a development process: gas invasion-overflow-kick-blowout-blowout out of control. Due to the characteristics of compression and expansion of gas, after the gas invades the drilling fluid, the gas volume is small due to the pressure of the upper liquid column ...

AI Technical Summary

Problems solved by technology

The monitoring of the outlet flow by the Corio type mass flowmeter is also completed above the wellhead, and the alarm still has a certain delay

The real-time measurement of annular pressure by downhole PWD combined with the hydraulic model can theoretically monitor the hydraulic conditions of the annular space. However, because the annular pressure is the result of the combined effect of annular flow pressure loss and drilling fluid static pressure, it is interfered by complex engineering factors. The influence of displacement and rheological parameter changes is greater, which makes it more difficult to identify kicks, and the decrease or increase of bottomhole pressure is not obvious, which will increase the possibility of misjudgment of kicks

Once a blowout occurs, it is not monitored by the PWD, which may also cause a blowout

[0005] To sum up, the early monitoring methods and devices for gas intrusion kicks currently used in land and offshore drilling operations have the disadvantages of delay and inaccurate discrimination in the monitoring of well kicks

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