MWD surface signal detector having bypass loop acoustic detection means

An apparatus for detecting pressure pulses in drilling fluid contained in a pipeline comprising:

• a bypass loop in parallel with a segment of the pipeline;
• a body in said bypass loop having a fluid passageway formed therethrough, said fluid passageway including a first region having a first cross sectional area that is smaller than the cross sectional area of the pipeline;
• a constrictor in said passageway defining a region of reduced cross sectional area relative to said first region;
• a first pressure tapping formed in said body and exposed to pressure in said first region;
• a second pressure tapping formed in said body and exposed to pressure in said region of reduced cross sectional area;
• a differential pressure transducer having input lines connected to said first and second pressure tappings;
• drilling fluid contained in said input lines and said bypass loop.

A method for detecting pressure pulses in drilling fluid flowing in a supply line comprising the steps of:

• providing a first and a second access port in the supply line;
• connecting a bypass loop between said first and second access ports such that said bypass loop is in parallel with a portion of the supply line, said bypass loop having a passageway that is smaller in cross sectional area than the supply line;
• providing a constriction in said passageway so as to form a region of reduced cross sectional area in said bypass loop;
• substantially filling said bypass loop with a medium capable of conducting pressure pulses;
• comparing the pressure in said region of reduced cross sectional area with the pressure in said passageway at a location outside said region of reduced cross sectional area.

An apparatus for detecting pressure pulses in a drilling fluid supply line comprising:

• a first port formed in the supply line;
• a second port formed in the supply line;
• a bypass loop interconnecting said first and second ports, said bypass loop being in parallel with the segment of the supply line disposed between said first and second ports, said bypass loop including a region of reduced cross-sectional area,
• first and second pressure ports formed in said bypass loop, one of said pressure ports intersecting said region of reduced cross-sectional area;
• and
• means for detecting the fluid pressure at said first and second pressure ports in said bypass loop.

An apparatus for detecting pressure pulses in a drilling fluid supply line comprising:

• a first port formed in the supply line;
• a second port formed in the supply line;
• a bypass loop interconnecting said first and second ports, said bypass loop being in parallel with the segment of the supply line disposed between said first and second ports;
• first and second pressure ports formed in said bypass loop;
• means for detecting the fluid pressure at said first and second pressure ports in said bypass loop;
• a generally tubular body having a fluid passageway therethrough, said passageway forming a portion of said bypass loop and including a first region having a first cross-sectional area and a second region having a second cross-sectional area that is smaller than said first cross-sectional area;
• wherein said first pressure port is formed in said body and intersects said fluid passageway in said first region;
• and
• wherein said second pressure port is formed in said body and intersects said fluid passageway in said second region.