Experimental device for drilling lubricity of horizontal well considering cuttings bed and experimental method

Abstract

The invention relates to an experimental device for the drilling lubricity of a horizontal well considering a cuttings bed, which comprises a simulated wellbore, wherein one end of the simulated wellbore is provided with a pulley, the other end is fixed with a hydraulic cylinder and equipped with a drill pipe, the drill rod is connected with a driving mechanism and a rotating mechanism, and the drill rod is provided with a thrust and torque sensor; there is a cuttings feeding port above the simulated wellbore, the cuttings feeding port is connected to a slurry tank through a fluid inlet pipeline, the fluid inlet pipeline is provided with a high pressure pump, a flowmeter and a pressure sensor; the lower end of the simulated wellbore is connected with a fluid return pipeline, the fluid return pipeline is provided with a temperature and pressure reducing mechanism, a flowmeter and a conveying pump; and the simulated wellbore is provided with an ultrasonic probe and is connected with a core holder, the holder is provided with a heating mechanism, a core and a pressure mechanism, and the inner side of the lower wall is provided with a cuttings lifting platform. In the experiment, cuttings and a drilling fluid are added, the pressure, the temperature and the cuttings thickness are adjusted, and composite drilling is simulated. The experimental device not only considers the frictionbetween a drill column and the drilling fluid, the well wall and a mud cake, but also considers the friction between the drill column and the cuttings bed, thereby being more in accordance with the actual working condition.

Description

technical field [0001] The invention belongs to the field of petroleum drilling, and in particular relates to a horizontal well drilling lubricity experimental device and an experimental method considering a cuttings bed. Background technique [0002] In recent years, with the rapid development of oil exploration and development technology and drilling technology, the drilling depth is getting deeper and deeper. Horizontal wells can cover multiple oil and gas reservoirs to achieve multiple production from one well. For horizontal wells, one of the major technical difficulties is that cuttings are difficult to carry, and they are easy to accumulate to form cuttings beds, which greatly reduces drilling efficiency. In addition, during the horizontal drilling process, the drill string is almost flat on the build-up section and the horizontal section. Downhole wall, the resulting cuttings bed will also seriously affect the lubricity of the drilling process. [0003] However, th...

AI Technical Summary

Problems solved by technology

For horizontal wells, one of the major technical difficulties is that cuttings are difficult to carry, and they are easy to accumulate to form cuttings beds, which greatly reduces drilling efficiency. In addition, during the horizontal drilling process, the drill string is almost flat on the build-up section and the horizontal section. downhole wall, the resulting cuttings bed also seriously affects the lubricity of the drilling process

[0003] However, the current research on the evaluation of drilling fluid lubricity at home and abroad only considers the friction between the drill string and drilling fluid, wellbore rock, and mud cake, but does not consider the friction between the drill string and the cuttings bed. During the process, the cuttings bed will increase the torque and friction during drilling and tripping, resulting in a decrease in the lubrication performance of the drilling fluid, which will cause a huge difference in the lubrication performance of the drilling fluid between indoor and field. The drilling fluid formula cannot meet the needs of on-site drilling

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