Patent Application
20080034856
a, 1b, and 1c illustrate a longitudinal cross-section of the apparatus of the present invention, and wherein, 1b is as extension of 1a, and 1c is an extension of 1b;
a is a cross-sectional view of sensor and data transmission means, showing the recessed insulated conductive element used to inject and/or receive currents into the formation;
b is a longitudinal cross section of the sensor and data transmission means showing the recessed insulated conductive element used to inject and/or receive currents into the formation.
a thru 1c shows a longitudinal cross section of the apparatus of the present invention, showing major components. The outer case or main housing 1, which may include multiple sections along its length, is shown to have a threaded tubular connection 2 at its upper end, for connection to other elements of a drill string above this apparatus indicated generally at 2a. A stator 3 and a rotor 4 for a “Moineau” or progressive-cavity type motor operated by the flow of drilling fluids pumped down through the drill string from the surface, are shown. A torsion bar or flexible shaft 6 is used to connect the eccentric motion of the rotor 4 to the lower elements of the apparatus. See connection 6a. The lower end of the shaft 6 is connected as at 6b to a rotary shaft 10 which drives a bit attached to the threaded connection 11 at the lower end of the apparatus. The bit diagrammatically indicated at 40. A bent subassembly 7 and 8 houses a radial and thrust bearing assembly 9 that transfers load from the bit at the lower end of the assembly, and shaft 10, to the case 8. Bending of the shaft 6 as shown accommodates both the eccentric motion of the rotor 4 and the bend angle between the axis 41 of the housing 1 and the bent axis 42 of the bent subassembly 7 and 8. As shown, axis 42 is concave toward axis 41, and convex radially away from axis 42. For suitable drilling operations the bend angle Δ between the housing axis 41 and the bent subassembly axis 42 may lie in the range of 0 to 4 degrees.
A sensor and data transmission assembly is provided at 5 adjacent case 1, and contains short range data transmission circuitry of the type shown in U.S. patent application Ser. No. 11/353,3624, “Electric Field Communication for Short Range Data Transmission in a Borehole”, wherein a recessed insulated conductive element is used to inject electrical signal currents outwardly directly into a formation 43 for detection at another nearby location in the drill string using another insulated conductive elements. The other nearby location is typically in the drill string as at 44 above this apparatus, where desired data may be transmitted on to a surface location by known transmission means. Two well known such means are by pressure pulses induced in the drilling fluid or by electrical transmission. Note particularly the parallel placement of the sensor and data transmission assembly 5 and the torsion bar or flexible shaft 6 such that no length is added to the total apparatus. Also note that the sensor and transmission assembly may be removed and replaced without any disassembly of the total apparatus. For this purpose assembly 5 may be located in a carrier 46 removably received sidewardly at 48 in a cavity 47 defined by housing section 1c.
Any selected array of sensors may be included in the sensor and data transmission assembly 5. Typically, such an array may include inclination sensors, direction sensors, formation resistivity sensors, gamma ray sensors, pressure sensors. RPM sensors, torque sensors, weight-on-bit sensors and temperature sensors. Requirements on what may be placed in the assembly 5 are fit and power requirements. A block diagram of sensor and data transmission assembly elements including elements of an upper location to communicate therewith, is shown in FIG. 5 of U.S. patent application Ser. No. 11/353,364, “Electric Field Communication for Short Range Data Transmission in a Borehole” incorporated herein by reference.
Drilling fluid enters the apparatus of the invention through the connection 2 and flows through the interior of the apparatus as at 12 and past shaft 6, to exit the apparatus into the drill bit at 40, through connection 11. Since the sensor and data transmission assembly 5 is in parallel with and located at one side of the torsion bar or flexible shaft 6, there is no need for an axial opening through the assembly 5 as is described for the sensor housing in U.S. Pat. No. 5,456,106.
a is a view of the sensor and data transmission means 5 showing the recessed insulated conductive element 5b and an insulating material 5a used to inject and/or receive currents into or from the formation, or to pass electric fields.
It will be seen from the above that one or more housing units extend lengthwise generally longitudinally, said torsion bar or flexible shaft also extending generally longitudinally, and said sensor and data transmission assembly is offset laterally from the torsion bar or flexible shaft which extends within said one or more housing unit sections. Also, it will be seen that the sensor and data transmission assembly includes an insulated electrically conductive element which extends longitudinally in a position which is recessed inwardly relative to a cylinder defined by the outer surface of said one or more housing units, and is also spaced laterally from said torsion bar or flexible shaft, whereby drilling fluid is flowable therebetween. Also, the housing defines a side recess, everywhere at one side of the output shaft, and which contains said data and transmission assembly, there being a fluid flow path between said shaft and said side recess.
This application claims priority from provisional application Ser. No. 60/836,486, filed Aug. 8, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60836486 | Aug 2006 | US |
