Early overflow and leakage monitoring system for well drilling

Abstract

The invention discloses an early overflow and leakage monitoring system for well drilling. The early overflow and leakage monitoring system for the well drilling comprises a Y-shaped elevated pipe; the Y-shaped elevated pipe comprises a main pipe and two measuring pipes, the two measuring pipes are symmetrically welded to the main pipe, an elevated hose-pipe is connected to one end of the Y-shapedelevated pipe, a pneumatic shut-off valve and an elevated pipe are connected to the other end of the Y-shaped elevated pipe through a flange, and shut-off valves and mass flow meters are correspondingly installed on the two measuring pipes; two buffer tanks are symmetrically distributed on both sides of the elevated pipe; and measurement signals of the mass flow meters, a mud pool level gauge, abell mouth level gauge, a pump stroke sensor, a turntable torque sensor, a turntable rotary speed sensor, a stand pressure sensor and a casing pressure sensor are transmitted to a monitoring control alarm device through signal cables, and the monitoring control alarm device controls a switch of the pneumatic shut-off valve and performs pre-alarm of overflow and leakage. The early overflow and leakage monitoring system for the well drilling is suitable for flow measurement of water-based and oil-based mud, and the monitoring accuracy of the wellbore outlet flow is improved.

Description

technical field [0001] The invention relates to early drilling overflow and leakage monitoring in the exploration and development drilling field of the petroleum and natural gas industry, and belongs to the technical field of drilling well control. Background technique [0002] In the process of oil and gas drilling, mud is generally used to balance the formation pressure. If the bottom hole pressure is not properly controlled, it will often cause overflow or lost circulation. If the overflow and leakage are not detected in time or handled improperly, it is likely to develop into a blowout. Once the blowout is out of control, it often causes huge property losses and even threatens the lives of personnel. At present, overflow and lost circulation are generally judged by monitoring the liquid level of the mud pool or the outlet flow of the wellbore. [0003] The liquid level monitoring of the mud pool is to use the liquid level gauge or the liquid level gauge to monitor the r...

AI Technical Summary

Problems solved by technology

In practical application, this method has great defects: 1. Since the wellhead mud needs to flow into the mud pool through elevated tanks, vibrating screens, grit chambers, etc., the mud passing path is long and there are many equipments, so the liquid level of the mud pool needs to be changed for a long time. time, resulting in a large delay in the monitoring of overflow and lost circulation. When the liquid level reaches the alarm value, the overflow and leakage in the wellbore are already very serious; 2. The volume of the mud pool is large. When overflow and lost circulation occur, the liquid level The range of ups and downs is small, and it is difficult to monitor the change of the liquid level in time, resulting in untimely detection of overflow and leakage, and delaying the timing of treatment; 3. The liquid level gauge is easily affected by the fluctuation of the mud pool liquid level, and manual recording of the liquid level gauge reading cannot guarantee the monitoring timeliness and reliability

This method directly monitors the outlet flow. Compared with the liquid level monitoring of the mud pool, it can monitor the overflow and lost circulation timely and has good reliability. However, there are also disadvantages: 1. The target flowmeter currently used is limited by its structural principle It has the characteristics of easy mud formation on the baffle plate, poor measurement accuracy, and poor working reliability, so it cannot be applied to the monitoring of early overflow and leakage

2. The dissatisfied pipe flow of the mud at the wellbore outlet, as well as the different physical properties of water-based and oil-based muds, have affected the use of high-precision flowmeters. The first mud logging company in Dagang, which was engaged in this research earlier, developed by Sun Hehui and others. Early overflow loss monitoring device, also only applicable to water-based mud

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