Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B47/00—Survey of boreholes or wells
  • E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
  • E21B47/14—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves
  • E21B47/18—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves through the well fluid, e.g. mud pressure pulse telemetry
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B47/00—Survey of boreholes or wells
  • E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
  • E21B47/14—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves
  • E21B47/16—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves through the drill string or casing, e.g. by torsional acoustic waves

Definitions

• the present invention relates to a method of transmitting drilling data from a well, from the bottom to the surface, and, more particularly to such a method using two parallel transmission channels between the bottom and the surface.
• the master driller When drilling a well, for example an oil well, it is desirable for the master driller to know the conditions existing at the bottom of the well (deflection factors, tool rotation speed, weight on the tool , tool torque, temperature, accelerations, etc.) to better control the drilling parameters. It is preferable to know these conditions in real time, this mistletoe requires means of transmitting data from the bottom of the well to the surface. Knowing the conditions of the bottom of the well allows drilling faster and reducing drilling costs. In addition, the master driller will be able to react quickly. - any change in conditions, for example, change in type of rock or wear of the tool.
• Several means of transmitting data from the bottom to the surface have been proposed. Among these means is transmission by electric conductor, by acoustic or electromagnetic waves.
• Pressure wave data transmission in drilling mud has also been proposed.
• the pressure of the mud flowing along the drill string is modulated, for example, by means of a servovalve mounted in a sub-assembly disposed in the drill string adjacent to the tool.
• the signal transmission speed in such a system is modest, the pressure waves only propagating at around 1500 m / s. Given the deterioration of the waves between the bottom and the surface, the limitations inherent in the modulation of the mud pressure, and the need to preserve the quality of the surface data the data rate remains low.
• the present invention aims to overcome the drawbacks of data transmission by pressure waves in the drilling mud by proposing a data transmission method which is simple and of increased reliability.
• the invention proposes a method of transmitting data for the drilling conditions of a well, from the bottom to the surface, comprising the following operations:
• the method comprises the additional operation of simultaneously detecting the vibrations generated in the drill string by said pulses in the drilling mud.
• FIG. 1 is a schematic sectional view of a drilling assembly
• FIG. 2 schematically shows a processing circuit.
• a drilling assembly comprising a mast 10 provided, in a manner known per se, with a hook 12 to which is suspended a drill string, generally represented at 14.
• the drill string 14 comprises a tool drill 16, drill rods 18 and drill rods 20.
• the drill string 14 is rotated by a rotation table 22 or by a motorized head called "power s ivel”.
• Pressurized drilling mud passes from a source (not shown) inside the rods 20 by a flexible conduit 24. This sludge is recycled to storage tanks (not shown) by a conduit 26.
• a servovalve mounted in a sub-assembly 28 disposed adjacent to the tool 16 is intended to selectively interrupt the flow of the pressurized mud in order to create pressure waves in the mud.
• Measuring devices and control are arranged in the 28-set in allowing, in a known way, to generate pressure waves in the mud that are represented "attempts measurements taken at the bottom. These pressic waves are detected at the surface by a pressure sensor 32 is mounted on the flexible conduit 24.
• the pressure waves created in the mud also generate corresponding vibrations in the drill string 14. According to the invention, it has been found that the reading of the data could be improved by mounting a second sensor on the drill string.
• the drilling assembly further comprises an accelerometer 34 mounted at the upper end of the drill string 14 and intended to measure the longitudinal acceleration of the drill rods 20.
• the circuit for processing the signals generated by the sensor 32 and the accelerometer 34 is shown diagrammatically in FIG. 2.
• the data provided by the additional gauge is used to further reduce the effects of extraneous noise. This data is processed in a parallel way in the diagram in Figure 2.
• the signals produced by the various sensors are processed in the circuit of Figure 2. As the propagation speed of the waves in the material of the drill string is at least three times greater than that in the drilling mud, the processing circuit must allow a temporal readjustment of the signals.
• This readjustment can be carried out either by intercorrelation of the signals, or from knowledge of the speeds in the two media. Then, a weighted averaging of the signals in the time domain should be carried out.
• a quality index is applied, established on each data channel with reference for example to a surface clock. This allows each data channel to be assigned a respective importance and can lead to the abandonment of a channel. An overall quality index could also be deduced from the inconsistencies between the signals, decoded separately.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Life Sciences & Earth Sciences (AREA)
• Acoustics & Sound (AREA)
• Remote Sensing (AREA)
• Fluid Mechanics (AREA)
• Environmental & Geological Engineering (AREA)
• Geophysics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Earth Drilling (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)
• Arrangements For Transmission Of Measured Signals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9400012

Family Applications (1)

Country Status (6)

Cited By (1)

Family Cites Families (6)

• 1990
  • 1990-08-31 FR FR9010910A patent/FR2666419B1/fr not_active Expired - Lifetime
• 1991
  • 1991-08-30 WO PCT/FR1991/000698 patent/WO1992004644A1/fr not_active Application Discontinuation
  • 1991-08-30 CA CA002072128A patent/CA2072128A1/fr not_active Abandoned
  • 1991-08-30 EP EP91916546A patent/EP0499635A1/de not_active Withdrawn
  • 1991-08-30 JP JP03514944A patent/JP3109741B2/ja not_active Expired - Lifetime
• 1992
  • 1992-04-30 OA OA60200A patent/OA09544A/fr unknown

Non-Patent Citations (1)

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