CN-121993066-A - Device and method for monitoring annular return flow of drilling fluid at normal pressure wellhead

CN121993066ACN 121993066 ACN121993066 ACN 121993066ACN-121993066-A

Abstract

The invention discloses an annular return flow monitoring device and method for drilling fluid at an atmospheric wellhead, which relate to the technical field of drilling, wherein an inlet of a bypass pipeline is connected with a side wall of a shaft, an inlet of a branch riser is connected with the bypass pipeline, an outlet of the branch riser is connected with an inlet of a downlink drain pipe, the inlet of the branch riser is lower than the outlet of the branch riser, the outlet of the downlink drain pipe and the outlet of the bypass pipeline can be connected with the inlet of a riser manifold, the outlet of the riser manifold is communicated with the wellhead of the shaft, a main flow monitoring structure and a main flow valve are arranged on the branch riser, a bypass flow monitoring structure and a bypass valve are arranged on the bypass pipeline, the main flow monitoring structure, the bypass flow monitoring structure, the return flow monitoring structure and the liquid level monitoring structure are all electrically connected with a data acquisition system. The invention can realize accurate measurement of flow.

Inventors

SUN XIAOFENG
LIU SHUJIE
ZHOU YINGCAO
XIAO CHENGCHENG
XU RUI
Hao Yaochi
WANG BIAO
SUN SHIHUI
QU JINGYU
HOU ZHAOKAI
HU QIAOBO

Assignees

东北石油大学

Dates

Publication Date: 20260508
Application Date: 20260309

Claims (10)

1. The device is characterized by comprising a main through pipeline, a bypass pipeline, a riser manifold, a liquid level monitoring structure and a data acquisition system, wherein the main through pipeline comprises a branch riser and a descending drain pipe, the inlet of the bypass pipeline is connected with the side wall of a shaft, the inlet of the branch riser is connected with the bypass pipeline, the outlet of the branch riser is connected with the inlet of the descending drain pipe, the inlet of the branch riser is lower than the outlet of the branch riser, the outlet of the descending drain pipe and the outlet of the bypass pipeline can be connected with the inlet of the riser manifold, the outlet of the riser manifold is communicated with the wellhead of the shaft, the branch riser is provided with the main through flow monitoring structure and the main through valve, the bypass pipeline is provided with the bypass flow monitoring structure and the bypass valve, the liquid level monitoring structure is used for monitoring the liquid level in the shaft, and the main through flow monitoring structure, the bypass flow monitoring structure, the return flow monitoring structure and the liquid level monitoring structure are electrically connected with the data acquisition system.
2. The apparatus of claim 1, wherein the inlet of the downstream drain is higher than the outlet of the downstream drain.
3. The apparatus of claim 1, wherein the inlet of the bypass line is higher than the outlet of the bypass line.
4. The apparatus of claim 1, wherein the riser is positioned at a highest level above the wellhead of the wellbore.
5. The apparatus for monitoring annular return flow of drilling fluid at an atmospheric wellhead according to claim 1, wherein the branch riser has an inner diameter equal to the diameter of the bypass line and an inlet lower than an outlet of the branch riser.
6. The apparatus of claim 1, further comprising a screen structure, wherein the outlet of the down drain and the outlet of the bypass line are both connected to an inlet of the screen structure, and wherein an outlet of the screen structure is connected to an inlet of the riser manifold.
7. The apparatus of claim 1, wherein the main valve and the bypass valve are electrically connected to the data acquisition system.
8. The atmospheric wellhead drilling fluid annulus return flow monitoring device of claim 1 wherein: still include the slush pump, the slush pump all sets up on the riser manifold.
9. The device for monitoring the annular return flow of drilling fluid at the constant pressure wellhead according to claim 8, wherein the diameter d of the downstream drain pipe is as follows: ; wherein f is a van der waals friction factor, L represents the length of a downlink liquid discharge pipe, Q represents the displacement of a slurry pump, m 3 /min, g is gravity acceleration, m/s 2 , and H represents the total water head, m.
10. A monitoring method employing the atmospheric wellhead drilling fluid annulus return flow monitoring device of any of claims 1-9, comprising: Step one, installing downlink liquid discharge pipes with different pipe diameters according to the flow rates of different times; step two, closing the bypass valve, opening the main through valve, monitoring the flow of the main through pipeline and the flow of the riser manifold, and monitoring the liquid level in the shaft: when the flow of the riser manifold is less than a preset value, there are two situations: 1. If the liquid level in the shaft is continuously reduced, judging that the shaft is lost, and continuing circulating drilling after the loss is treated, and returning to the step two; 2. If the liquid level in the shaft is continuously increased, the main through pipeline is judged to be blocked, the main through valve is closed, and the bypass valve is opened until the flow of the bypass pipeline is monitored to be stable: When the flow of the main communication pipeline is continuously increased and the liquid level in the shaft is continuously increased, judging that the shaft overflows, and continuing drilling after well closing and well killing, and returning to the step two; Step three, judging whether to change the time: if the first step is not replaced, returning to the second step; If the number of times of replacement is changed, the process returns to the step one.

Description

Device and method for monitoring annular return flow of drilling fluid at normal pressure wellhead Technical Field The invention relates to the technical field of drilling, in particular to an annular return flow monitoring device and method for drilling fluid at an atmospheric wellhead. Background The front edge of the oil and gas resource exploration and development field is expanded to a complex stratum characterized by high pressure and high safety density, and well leakage and overflow accidents are extremely easy to induce in the environment of the extreme working conditions. However, the conventional monitoring and measuring method has the defects of strong hysteresis, weak anti-interference capability and low detection sensitivity, and can not realize the identification of early abnormal working conditions of the wellhead, thereby causing great potential safety hazards of well control. In order to acquire more real-time shaft dynamic information, delay is prevented, a monitoring point is moved to a return pipeline based on a drilling fluid inlet and outlet balance principle, flow detection is carried out, and dynamic change in the shaft is fed back in time. The pressure control well drilling realizes wellhead closed loop by rotating the blowout preventer, and back pressure is applied by utilizing the choke manifold, so that the back pipeline is in a state of being pressurized and full of pipes, and the measuring requirement of the flowmeter on the fluid medium full of the pipes is met. However, conventional drilling, where the wellhead is connected to the atmosphere, the return line forms an "open channel" under the action of the atmosphere, failing to meet the measurement standards of the flowmeter. The conventional well drilling return line flow measurement has the bottleneck of low precision and poor engineering adaptability, and the urgent need of early and accurate identification of a wellhead cannot be realized. Disclosure of Invention The invention aims to provide a device and a method for monitoring annulus return flow of drilling fluid at an atmospheric wellhead, so as to solve the problems in the prior art and realize accurate measurement of flow. In order to achieve the above object, the present invention provides the following solutions: The invention provides an annular return flow monitoring device for drilling fluid at an atmospheric wellhead, which comprises a main through pipeline, a bypass pipeline, a riser manifold, a liquid level monitoring structure and a data acquisition system, wherein the main through pipeline comprises a branch riser and a descending drain pipe, the inlet of the bypass pipeline is connected with the side wall of a shaft, the inlet of the branch riser is connected with the bypass pipeline, the outlet of the branch riser is connected with the inlet of the descending drain pipe, the inlet of the branch riser is lower than the outlet of the branch riser, the outlet of the descending drain pipe and the outlet of the bypass pipeline can be connected with the inlet of the riser manifold, the outlet of the riser manifold is communicated with the wellhead of the shaft, the main through flow monitoring structure and the main through valve are arranged on the branch riser, the bypass flow monitoring structure and the bypass valve are arranged on the bypass pipeline, the liquid level monitoring structure is used for monitoring the liquid level in the shaft, and the main through flow monitoring structure, the bypass flow monitoring structure, the return flow monitoring structure and the liquid level monitoring system are electrically connected with the data acquisition system. In some embodiments, the inlet of the downstream drain is higher than the outlet of the downstream drain. In some embodiments, the inlet of the bypass line is higher than the outlet of the bypass line. In some embodiments, the uppermost position of the branch riser is no higher than the wellhead of the wellbore. In some embodiments, the inner diameter of the branch riser is equal to the pipe diameter of the bypass line, and the inlet of the bypass line is lower than the outlet of the branch riser. In some embodiments, the system further comprises a screening structure, wherein the outlet of the down drain pipe and the outlet of the bypass line are both connected to an inlet of the screening structure, and an outlet of the screening structure is connected to an inlet of the riser manifold. In some embodiments, the main valve and the bypass valve are both electrically connected to the data acquisition system. In some implementations, a mud pump is also included, each disposed on the riser manifold. In some embodiments, the pipe diameter d of the downstream drain pipe has the following value:; wherein f is a van der waals friction factor, L represents the length of a downlink liquid discharge pipe, Q represents the displacement of a slurry pump, m 3/min, g is gravity acceleration, m/s 2, and H represe