Balanced pressure drilling pressure control device and method

Abstract

The invention provides a balanced pressure drilling pressure control device and a method for conducting well drilling pressure control through the balanced pressure drilling pressure control device. In the balanced pressure drilling pressure control device, a wellhead rotary blowout preventer is installed at the upper end of a wellhead blowout preventer set, and the wellhead rotary blowout preventer and a pressure control throttling pipe manifold are connected through a high-pressure pipeline, and a kill manifold is connected with a well drilling fluid filling system through a wellhead four-way part. A filling pump, a gate valve and a check valve are installed on the well drilling fluid filling system in sequence at the outlet end of the kill manifold, and the filling pump is connected with a well drilling fluid circulating tank through a pipeline. The pressure control throttling pipe manifold is connected with a liquid-gas separator through a pipeline, and then is connected to the well drilling fluid circulating tank, so that the well drilling fluid cycle is formed. Compared with an existing pressure control well drilling method, the method has the advantages that facilities and devices such as a return pressure pump and a flowmeter are not arranged on the ground, no pressure measuring transmission devices exist in a well, and matching is easy; and due to the fact that control is conducted according to the stability of the amount of fluid in the well drilling fluid circulating tank in drilling operation, and the size of a drilling stem in tripping operation, and measurement, metering and operation are quite easy and convenient.

Description

technical field [0001] The invention relates to a balanced pressure drilling pressure control device in the technical field of drilling and a method for drilling pressure control using the device. Background technique [0002] Managed pressure drilling technology is a new drilling technology developed in recent years. It is mainly used to protect underground resources such as oil and gas layers, prevent lost circulation during drilling, ensure drilling well control safety and speed up drilling. However, the current managed pressure drilling methods are mainly "bottom hole constant pressure" control method and "micro flow control" control method, which cannot consider and control the bottom hole pressure and formation pressure, and cannot achieve a real-time balance between the two , the drilling of the "zero pressure window" formation cannot be realized. Moreover, the supporting equipment is complicated, the control requirements are high, and the on-site implementation is d...

AI Technical Summary

Problems solved by technology

[0007] There are four problems in this control method: First, the control purpose is "constant bottom hole pressure", that is, p b =p ma +p la +p ax (p b is the bottom hole pressure, p ma is the hydrostatic pressure of the annular space, p la is the annular pressure loss during the cycle, p ax is wellhead back pressure), without considering the balance between bottom hole pressure and formation pressure

The system needs to add back pressure pumps, high-precision inlet and outlet flowmeter devices and instruments, and there are problems such as complex matching and difficult control

For drilling in supersaturated saline layers, the allowable overflow volume of 800L cannot meet the downhole safety requirements

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