Short hop communication link for downhole MWD system

A short-hop electromagnetic communication based data acquisition system for transmission of measured operating, environmental and directional parameters in a well, comprising:

• (a) a drill string including a bottom-hole assembly, terminating in a drill bit;
• (b) motor means for operating said drill bit;
• (c) means for connecting said motor means to said drill bit;
• (d) means for sensing any one of said parameters and generating an output signal indicative thereof, said sensing means being housed in said connecting means;
• (e) transmission means for receiving the output signal from said sensing means and for generating an electromagnetic data signal, said transmission means being housed in said connecting means;
• and
• (f) data communication control means forming part of said bottom-hole assembly and positioned uphole from said motor means, said data communication control means including a receiver means for receiving the electromagnetic data signal.

A downhole telemetry system for transmitting data signals between two points downhole in a well, comprising:

• a drill bit;
• a pulser collar located above said drill bit for transmitting mud pulses to an acoustic receiver located near the surface of the well;
• a control module located above said pulser collar and connected electrically to said pulser collar and disposed at a subsurface location downhole of and remote from the acoustic receiver;
• tubing means positioned between said pulser collar and said drill bit;
• transmitter means positioned in said tubing means for transmitting the data signals;
• and
• receiver means positioned in said control module for receiving the data signals transmitted from said transmitter means.

A system for transmitting signals a relatively short distance downhole, comprising:

• a downhole component disposed at a subsurface location;
• sensor means disposed below said downhole component for monitoring at least one of the operational, environmental, and directional parameters, downhole and providing electrical signals indicative thereof;
• a first subsurface transceiver means, electrically connected to said sensor means, positioned on the downhole side of said component for obtaining said electrical signals from said sensor means and transmitting electromagnetic data signals correlative to said electrical signals;
• and
• second subsurface transceiver means positioned on the uphole side of said component for receiving said electromagnetic data signals from said first transceiver means.

A short-hop electromagnetic communication based data acquisition system for transmission of measured operating, environmental and directional parameters in a well, comprising:

• (a) motor means with an extended driveshaft;
• (b) means for sensing one of said parameters and generating an output signal indicative thereof, said sensing at least means being housed in said extended driveshaft;
• (c) transmission means for receiving the output signal from said sensing means and for generating an electromagnetic data signal, said transmission means being housed in said extended driveshaft;
• and
• (d) data communication control means positioned at a subsurface location uphole from said motor means, said data communication means including receiver means for receiving the electromagnetic data signal.

A short-hop electromagnetic communication based data acquisition system for transmission of measured operating, environmental and directional parameters near the motor a short distance in a well, comprising:

• (a) means for sensing at least one of said parameters and generating an output signal indicative thereof, said sensing means being housed in a sub below said motor;
• (b) transmission means for receiving the output signal from said sensing means and for generating an electromagnetic data signal, said transmission means also being housed in said sub;
• (c) data communication control means positioned uphole from said motor, said data communication means including
• (1) receiver means positioned a short distance from said transmission means for receiving the electromagnetic data signal, and
• (2) a telemetry means for communicating information reflecting the electromagnetic data signal to the surface;
• (d) a battery connected to said transmission means and said sensing means for supplying power, said battery being housed in said sub.

A method for communicating operating, environmental and directional parameters from near a drill bit, around a motor, to the surface of a well, including the steps of:

• (a) sensing at least one of said parameters;
• (b) transmitting an electromagnetic signal indicative of said sensed parameter a relatively short distance from below the motor;
• (c) receiving the electromagnetic signal at a point above the motor;
• (d) converting at least a portion of the electromagnetic signal to a mud pulse signal;
• and
• (e) transmitting said mud pulse signal to the surface.

A method for communicating parameters measured near a drill bit to a point above a motor, including the steps of:

• (a) transmitting a command signal from the point above the motor;
• (b) receiving the command signal at a point in a bottom-hole assembly below the motor;
• (c) deciphering the command signal to determine the parameter desired;
• (d) sensing the desired parameter;
• (e) transmitting a signal indicative of said sensed parameter a relatively short distance from below the motor;
• (f) receiving the signal at a subsurface point above the motor and within said relatively short distance;
• (g) analyzing the signal to recover information indicative of the desired parameter.

A method for communicating parameters measure near a drill bit in a well to a point above a motor, including the steps of:

• (a) transmitting a command signal from a first downhole point in a downhole assembly above the motor at a variety of frequencies, said first downhole point being remote from the surface of the well;
• (b) receiving the command signal at a second downhole point below the motor;
• (c) determining the frequency which delivers the best signal-to-noise ratio for the transmission from said first downhole point to said second downhole point;
• (d) transmitting a signal from said second downhole point to said first downhole point indicative of the desired parameter, at the frequency with the best signal-to-noise ratio.

An apparatus measuring parameters near the drill bit, comprising:

• a bottom-hole assembly, including a drill bit;
• a downhole motor, in the bottom-hole assembly, positioned above the drill bit;
• a sensor module, in the bottom-hole assembly, positioned between the drill bit and the motor, said sensor module including a first transceiver means and a processing means;
• a control module, in the bottom-hole assembly, positioned above the motor, said control module including a second transceiver means;
• wherein said second transceiver means emits a sounding signal at a variety of frequencies which are detected by said first transceiver means, and said processing means analyzes the received signals to determine which frequency has the best signal-to-noise ratio.

A short-hop electromagnetic communication based data acquisition system for transmission of measured operating, environmental and directional parameters in a well, comprising:

• (a) a downhole assembly terminating in a drill bit;
• (b) a downhole component;
• (c) connecting means for connecting said downhole component to said drill bit;
• (d) means for sensing at least one of said parameters and generating an output signal indicative thereof, said sensing means being housed in said connecting means;
• (e) transmission means for receiving the output signal from said sensing means and for generating an electromagnetic data signal, said transmission means being housed in said connecting means;
• and
• (f) data communication control means positioned in said downhole assembly uphole from said downhole component, said data communication control means including a receiver means for receiving the electromagnetic data signal.