Method and device for controlling pressure during aerated dual-gradient drilling for riser

Abstract

The invention discloses a structure diagram of a method and device for controlling a pressure during aerated dual-gradient drilling for a riser. The device is mainly composed of an upper-part riser, an upper gas-injection channel, a balance communication device, a lower gas-injection channel, a drill rod, a lower-part riser, a blowout preventer, a seabed high-pressure pump, a pressure stabilizer,an emergency cut-off electromagnetic valve C, a blocking device, a high-pressure hydraulic oil conveying pipe and a drilling platform, wherein the upper-part riser extends downwards from the drillingplatform, the lower-part riser extends downwards from the blocking device, and the high-pressure hydraulic oil conveying pipe is arranged on the blocking device; an upper port of the balance communication device is connected with the upper-part riser above the blocking device, and a lower port of the balance communication device is connected with the lower-part riser below the blocking device; theblowout preventer is arranged at a seabed well mouth; the emergency cut-off electromagnetic valve C is arranged in a pipeline of the seabed high-pressure pump, and a pressure reduction pipeline and apressure increasing pipeline are arranged on the seabed high-pressure pump. The device is capable of accurately controlling a bottom-hole pressure in time, and adaptive to varied actual engineering conditions, so that the safe progress of deep sea drilling is ensured.

Description

technical field [0001] The patent of the present invention relates to riser-inflated dual-gradient drilling, in particular to a method and device for controlling pressure in riser-inflated dual-gradient drilling. Background technique [0002] With the intensification of offshore oil and gas exploration and development, drilling in various complex areas is increasing, and the application of conventional drilling technology in these areas may lead to many drilling problems: a large amount of drilling fluid loss caused by leaky formations, blowout accidents, Drill sticking and other downhole complex accidents; at the same time, it will also cause damage to the production layer. Drilling in many areas of our country, the non-operating drilling time is mainly caused by lost circulation, blowout and other downhole complex accidents. Especially in the process of drilling, a large amount of drilling fluid is often leaked, or even leaked and lost, causing blowout accidents, causing ...

AI Technical Summary

Problems solved by technology

[0002] With the intensification of offshore oil and gas exploration and development, drilling in various complex areas is increasing, and the application of conventional drilling technology in these areas may lead to many drilling problems: a large amount of drilling fluid loss caused by leaky formations, blowout accidents, Pipe sticking and other downhole complex accidents; at the same time, it will also cause damage to the production zone

Compared with long-distance well sections, the amount of air charged cannot effectively change the bottomhole pressure in a short period of time, let alone make timely and effective responses to the ever-changing actual engineering conditions

Images