Development of mechanical tool for automatic vertical drilling

In order to effectively improve the penetration rate and quality in vertical drilling,a mechanical tool for automatic vertical drilling was developed by using the current technologies.The mechanical tool can timely respond to the gravity signal of drilling tool while well deviation happens.The actuator can be driven by the gravity of drilling tool and push the piston towards the borehole wall on the higher side under the created pressure difference inside and outside the rotating drill string resulted from the circulation of drilling fluid.The periodic lateral force was acted on the lower side of the borehole in the drilling bit.The deviation of well bore can be timely modified during drilling.Field test results show that the mechanical tool for automatic vertical drilling has the appropriate operating principle,reliable structure and well deviation resistance and also can simultaneously release the drilling pressure and effectively improve the drilling rate.This drilling tool presents an extensive prospect in field application.