A Lubricity Experimental Device and Experimental Method for Horizontal Well Drilling Considering Cuttings Bed

Abstract

The horizontal well drilling lubricity experiment device considering the cuttings bed includes a simulated wellbore with a pulley at one end, a hydraulic cylinder fixed at the other end, and a drill pipe connected with a driving mechanism and a rotating mechanism. There are thrust and torque sensors; there is a cuttings feeding port above the simulated wellbore, which is connected to the mud tank through the liquid inlet pipeline, and a high-pressure pump, flow meter, and pressure sensor are installed on the liquid inlet pipeline; the lower end of the simulated wellbore is connected to the liquid return pipeline. The liquid pipeline is equipped with a cooling mechanism, a flow meter, and a delivery pump; the simulated wellbore is equipped with an ultrasonic probe connected to a core holder, and the holder is equipped with a heating mechanism, a core, and a pressure mechanism, and a cuttings lifting device is installed on the inner side of the lower wall. step down. During the experiment, cuttings and drilling fluid were added, pressure temperature and cuttings thickness were adjusted, and composite drilling was simulated. Since the present invention not only considered the friction between the drill string and drilling fluid, well wall, and mud cake, but also considered the The friction force of the cuttings bed is more in line with the actual working conditions.

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...

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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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