Method for solving air screw drill runaway problem and pneumatic speed limiting valve device
A technology of screw drilling tools and speed-limiting devices, which is applied to the valve device of wellbore/well, drilling with liquid/gas jet, earth-moving drilling, etc. The effect of improving drilling efficiency, prolonging working life and reducing drilling cost
Inactive Publication Date: 2006-12-13
CNPC DRILLING RES INST
View PDF0 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0007] (1) Increased ground equipment;
[0008] (2) causing a large power loss;
[0009] (3) The control effect is not good, because the soft characteristics of the air drive make the motor characteristics change with the well depth, the reasonable flow adjustment is variable, and 1 / 2Q is not the only constant optimal value;
[0010] (4) The difficulty of operation is increased, because lifting off the bottom of the well is a frequent operation, and it is stipulated to operate the surface flow valve before lifting the drill, which is troublesome and easy to make mistakes
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0024] The method provided by the present invention to solve the problem of air screw drill runaway is to set at least one passage leading to the upper and lower ends inside the rotor of the air screw drill motor, and to determine the direction of the passage through a control valve that uses the pressure difference at both ends of the passage as a signal. In the opening and closing state, the passage is closed when the air screw drilling tool is drilling, and the passage is opened when the pump is idling, and the air volume entering the motor is automatically adjusted to suppress the runaway.
[0025] Specifically, a pneumatic speed limiting device can be installed on the upper end of the rotor of the air screw drilling tool as a speed limiting valve, and the rotor is provided with at least one passage (the central through hole of the motor rotor) in the axial direction, leading to the lower end of the speed limiting device; The outlet, that is, the pressure difference Δp betw...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The present invention relates to method and equipment as the solution of runaway problem of air screw rod drilling tool. The method is to control the rotation speed of bit in air screw rod drilling tool while being separated from the bottom of well by means of the pressure difference method based on automatic control principle. The equipment includes one pneumatic speed-limiting valve mounted to the rotor of the air screw rod drilling tool and the rotor with one central via hole in the lower end of the valve. The pressure difference between of motor air inlet during idle rotation and that during drilling is used as the control signal in regulating the working state of the speed imitating valve to limit the speed of the motor. The automatic control can prolong the service life of the air screw rod drilling tool and raise well drilling efficiency.
Description
[0001] Field [0002] The present invention relates to a kind of oil drilling, in particular to a method and device for solving the problem of air screw drill runaway by using the differential pressure method. Background technique [0003] In oil and gas drilling, screw drilling tools (PDM, Positive Displacement Motor) are often used. Conventional screw drilling tools use drilling fluid (commonly known as mud) as the power transmission medium, and convert the liquid pressure energy from the ground drilling pump into the mechanical energy of the screw drilling tool and the work of the drill bit to break rocks. Due to the incompressibility of the liquid and the characteristics of the screw drilling tool as a volumetric machine, when the drilling tool is lowered to make the drill bit touch the bottom of the well for drilling or the drilling tool is lifted to make the drill bit leave the bottom of the well for idling circulation, the rotational speed of the screw drill and the dri...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): E21B34/06E21B7/18
Inventor 苏义脑窦修荣王家进张润香
Owner CNPC DRILLING RES INST