Simulation experiment method for determining thickness of rock debris bed based on measurement of fluid speed

Abstract

The invention discloses a simulation experiment method for determining a thickness of a rock debris bed based on measurement of a fluid speed. The method comprises the following steps that 1, a simulated wellbore, a simulated drill string and a flow meter are arranged; 2, a drilling fluid is injected into the simulated wellbore, the simulated drill string is controlled to rotate, a reinjection mechanism injects rock debris into the simulated wellbore, and then a discharging rate of a drilling fluid injection mechanism and a flow rate of the drilling fluid are obtained separately; 3, a cross-sectional area of annulus corresponding to the flow meter in the wellbore are simulated according to the discharging rate and the flow rate; 4, a ratio of the rock debris bed in an area corresponding tothe flow meter in the simulated wellbore to the simulated wellbore according to an inner diameter of the simulated wellbore, an outer diameter of the simulated drill string and the cross-sectional area obtained in the third step; and 5, the thickness of the rock debris bed in the area corresponding to the flow meter in the simulated wellbore is calculated according to the internal diameter of thesimulated wellbore and the ratio of the rock debris bed to the simulated wellbore obtained in the step 4. The method can determine the thickness of the rock debris bed in a water-based / oil-based drilling fluid state at a low cost, and can effectively provide guidance for horizontal well rock debris bed research.

Description

technical field [0001] The invention relates to the technical field of petroleum drilling, in particular to a simulation experiment method for judging the thickness of a cuttings bed based on the measured fluid velocity. Background technique [0002] During the drilling process of highly deviated wells and horizontal wells of oil and gas, cuttings often fail to migrate smoothly and form cuttings beds, which leads to complex problems such as increased friction and poor drilling, and even affects drilling safety in severe cases. With the continuous extension of the horizontal section, the problem of cuttings beds in horizontal wells with long horizontal sections becomes more prominent. How to effectively judge the state of cuttings beds in the horizontal section is the focus and hotspot of current research. [0003] At present, it is an effective method to study the cuttings bed migration law in the horizontal section of the downhole by using the ground simulation experiment d...

AI Technical Summary

Problems solved by technology

[0005] 1. Due to the addition of various chemical substances in the drilling fluid, the working environment of the ultrasonic probe is harsh, and it is easily affected by the drilling fluid, resulting in abnormal signals and failure to work;

[0006] 2. Affected by the flow of drilling fluid, the measurement accuracy and sensitivity of the ultrasonic probe will be reduced, resulting in inaccurate measurement

[0007] 3. The price of the ultrasonic probe is relatively high, which leads to a correspondingly high measurement cost

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