HORIZONTAL WELL DRILLING APPARATUS FOR TESTING LUBRICITY AND TESTING METHOD, TAKING CUTTINGS BED INTO ACCOUNT

摘要

A horizontal well drilling apparatus for testing lubricity, taking a cuttings bed into account. The testing apparatus comprises a simulated wellbore (8), wherein one end of the simulated wellbore is provided with a pulley (16), and the other end is fixed with a hydraulic cylinder (38) and installed with a drill pipe (5), the drill pipe (5) being connected to a drive mechanism (1) and a rotation drive mechanism (4), and the drill pipe (5) being provided with a thrust sensor (2) and a torque sensor (3); a cuttings feeding port (9) is arranged above the simulated wellbore (8), and is connected to a slurry tank (24) via a fluid inlet pipeline (18), the fluid inlet pipeline (18) being provided with a high-pressure pump (23), a flowmeter (22) and a pressure sensor (19); a lower end of the simulated wellbore (8) is connected to a fluid return pipeline (26), the fluid return pipeline (26) being provided with a temperature- and pressure-reducing mechanism (29), a flowmeter and a conveying pump (28); and the simulated wellbore (8) is provided with an ultrasonic probe (6) and is connected to a core holder (13), the core holder (13) being provided with a heating mechanism, a core (11) and a pressure mechanism, and an inner side of a lower wall of the simulated wellbore is provided with a cuttings lifting platform (7). According to the apparatus, during a test, cuttings and a drilling fluid are added, and the pressure, the temperature, and the thickness of the cuttings are adjusted to simulate composite drilling. The apparatus not only takes the friction between a drill column and the drilling fluid, a well wall and a mud cake into account, but also takes the friction between the drill column and a cuttings bed into account, thus being more in keeping with actual working conditions.