Drilling downhole gas cut monitoring and intelligent well control system and implementation method

Abstract

The invention relates to a drilling downhole gas cut monitoring and intelligent well control system and an implementation method, and belongs to the technical field of oil and gas drilling. A cyclonegenerator is redesigned to effectively prolong the service life of the cyclone generator and improve the precision of ultrasonic gas cut monitoring. The underground gas cut degree is divided into three well control risk levels, and the underground gas cut well control risk levels and wellbore pressure information are sent to the ground through an underground monitoring signal transmission path, sothat a reliable basis and precious time are provided for implementing a reasonable well control plan on the ground; for low-risk gas cut and medium-risk gas cut, the system automatically judges the gas cut degree and controls the opening degree of a packer in real time, and real-time control over the wellbore pressure and the gas cut is achieved by reducing the pressure drop generated by the section area of an annulus flow channel; and for high-risk gas cut, the system can automatically pack a wellbore and an annulus and construct a weighted drilling fluid pumping channel, the wellbore annulus pressure and the formation pressure are restored to be balanced, the system is more intelligent and efficient, and the risks and the well control cost are reduced.

Description

technical field [0001] The invention relates to a downhole gas invasion monitoring, intelligent well control system and implementation method, belonging to the field of oil and gas drilling. Background technique [0002] Intelligent drilling technology is the future development direction in the field of drilling engineering, and the existing drilling technology is gradually developing in the direction of informatization, automation and intelligence. In the field of well control, the early monitoring and control of gas kick is very important, and it is also one of the research hotspots in recent years. How to detect downhole gas invasion as soon as possible and accurately and quickly implement effective well control measures is a current technical problem. [0003] Chinese patent document CN111255443A discloses an intelligent downhole gas invasion control system, which monitors the viscosity and resistivity changes of the drilling fluid to judge whether there is gas invasion...

AI Technical Summary

Problems solved by technology

However, the patent document CN111255443A can only judge the occurrence of gas invasion and directly implement the measure of "temporarily sealing off the wellbore and injecting heavy drilling fluid", but cannot judge the degree of gas invasion and implement different levels of well control measures according to the degree of gas invasion. Aggravating the drilling fluid is time-consuming and costly. It is a well control measure that has to be taken in view of the large well control risk. It is applied to low- and medium-risk gas invasion, which increases the control time and economic cost; Real-time monitoring of downhole gas invasion degree and well control risk level

[0004] Chinese patent document CN202010209748.8 aims at the problem of low resolution of bubbles and cuttings by ultrasonic waves, and proposes a monitoring scheme based on downhole gas-solid separation, which greatly improves the recognition accuracy of ultrasonic waves for gas intrusion. However, patent document CN202010209748.8 The gas-solid separation system in the technical plan is only an early monitoring plan for gas kick, and there is still a period of manual judgment and operation between "monitoring to the occurrence of gas kick" and "successful implementation of effective well control measures", which reduces the risk of gas kick. Invasion well control efficiency and increased uncertainty

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