Well pipe or object depth indicator

In a method of continuously displaying the total depth of a well string while accommodating raising and lowering the well string supported on a travelling block relative to a crown block on a mast and formed of a plurality of independently rotatable sheaves and wherein a drill line reeved on a drawworks extend around the crown block sheaves and the travelling block with one end of the drill line anchored whereby the travelling block and supported well string may be raised and lowered in a well bore and the total depth of the well string may be continuously measured and displayed at the earth's surface, the steps comprising:

• a. positioning circumferentially spaced magnets on one of the rotatable sheaves of the crown block;
• b. positioning movement measuring means including sensor means to electronically sense the amount and direction of movement of the sheave having the magnets thereon by producing an electronic signal each time one of the magnets passes the sensor means;
• c. electronically coupling electronic totalizer means including a computer counter circuit capable of being preset and having memory with the movement measuring means to instrumentally display the continuous total depth of the well string;
• d. electronically coupling a power source to the totalizer means;
• e. electronically coupling normally open switch means between the totalizer means and movement measuring means, and coupling the switch means with the drill line to close the switch means and supply power to the movement measuring means when the weight of the well string on the drill line exceeds a predetermined amount;
• f. supplying power to the movement measuring means to bypass the switch means when the drill line is moved longitudinally of the mast a predetermined distance;
• g. instrumentally noting on the totalizer means the number of electronic signals generated by the movement measuring means during such predetermined longitudinal movement of the drill line as an indication of the number of magnets passing the sensor means;
• h. determining the amount of longitudinal travel of the drill line for each magnet that passes the sensor means by the expression:
• predetermined longitudinal travel distance of the drill line divided by total number of signals reflected on the totalizer means during such predetermined longitudinal travel distance;
• i. presetting the computer counter circuit of said totalizer means with the amount of longitudinal travel of the drill line for each magnet that passes the sensor means as determined by the immediately preceding recited step;
• j. removing the power bypass to the movement measuring means whereby the switch means thereafter controls the supply of power to the movement measuring means in response to the well string weight when supported on the drill line.

Apparatus for displaying the total depth of an object supported in a well bore by a cable line reeved around at least one rotatable sheave means supported on a mast including:

• movement measuring means for sensing the amount and direction of movement of the cable line around the sheave means said movement measuring means including:
• detectable means mounted at equally spaced circumferential postions on the sheave means;
• and
• sensor means for responding to said detectable means to produce a signal in response to movement of the sheave means with the cable line thereon;
• totalizer means including computer means capable of being preset and having memory for displaying the total depth of the object;
• coupling means including communicating means for communicating the signals from said sensor means to said totalizer means only when the weight of the object supported by the cable line exceeds a predetermined amount;
• means for maintaining said communicating means operative to bypass said coupling means when it is desired to move the cable line a predetermined longitudinal amount relative to the mast with the weight of the object supported by the cable line less than said predetermined amount;
• and
• means for instrumentally noting on said totalizer means the number of signals transmitted by said sensor means during such predetermined cable line longitudinal movement as an indication of the amount of longitudinal travel of the cable line for each detectable means whereby said computer means may be preset with the amount of longitudinal travel of the cable line for each detectable means that passes said sensor means.

Apparatus for displaying the total depth of an object supported in a well bore by a cable line reeved around at least one rotatable sheave means including:

• movement measuring means for sensing the amount and direction of movement of the cable line around the sheave means said movement measuring means including:
• detectable means mounted at equally spaced circumferential postions on the sheave means;
• and
• sensor means for responding to said detectable means to signal rotation of the sheave means with the cable line thereon;
• totalizer means including computer means capable of being preset and having memory for displaying the total depth of the object;
• coupling means for communicating the signals from said sensor means to said totalizer means when the weight of the object supported by the cable line exceeds a predetermined amount;
• coupling means for interrupting the signals from said sensor means to said totalizer means when the weight of the object supported by the cable line is less than said predetermined amount;
• means for bypassing said coupling means when it is desired to move the cable line a predetermined longitudinal amount so that said sensor means remains coupled to communicate signals to said totalizer means as an indication of the total number of detectable means sensed by said sensor means during such predetermined cable line longitudinal movement;
• and
• means for instrumentally noting on said totalizer means the number of signals sensed by said sensor means during such predetermined cable line longitudinal movement as an indication of the amount of longitudinal travel of the cable line for each detectable means whereby said computer means may be preset with the amount of longitudinal travel of the cable line for each detectable means that passes said sensor means.

In a method of continuously displaying the total depth of an object in a well bore while accommodating raising and lowering the object supported on a cable line reeved around at least one rotatable sheave means, the steps of:

• a. positioning circumferentially spaced detectable means on one of the rotatable sheave means;
• b. positioning sensor means to sense the amount of movement of the sheave means by producing a signal each time one of the detectable means passes the sensor means;
• c. communicating totalizer means including a computer counter circuit capable of being preset and having memory with the sensor means to instrumentally display the continuous total depth of the well string;
• d. moving the cable line longitudinally a predetermined amount;
• and
• e. receiving in the totalizer means the number of signals generated by the sensor means during such predetermined longitudinal movement of the drill line as an indication of the number of detectable means passing the sensor means whereby the totalizer means may be preset with the amount of longitudinal movement of the cable line for each detectable means that passes said sensor means.

Apparatus for continuously displaying the total depth of an object supported in a well bore on a cable line reeved around rotatable sheave means comprising:

• movement measuring means for sensing the amount and direction of movement of the cable line around the sheave means;
• detectable means mounted at equally spaced circumferential positions on the sheave means;
• and
• sensor means for sensing the amount and direction of movement of the cable line that extends around the sheave means by producing a signal in response to said detectable means;
• totalizer means including means capable of being preset and having memory for responding to said movement measuring means to instrumentally display the continuous total depth of the well string;
• means for coupling a power source to said totalizer means;
• normally open switch means;
• means for coupling said normally open switch means between said totalizer means and said movement measuring means and for coupling said switch means with the cable line for supplying power to said movement measuring means when the weight of the object on the cable line exceeds a predetermined amount;
• means operable to bypass said switch means for supplying power to said movement measuring means and for coupling said movement measuring means to said totalizer means when the cable line is moved longitudinally relative to the mast a predetermined amount;
• and
• means for instrumentally noting on said totalizer means the number of detectable means sensed by said sensor means during such predetermined longitudinal movement of the cable line whereby said totalizer means may be preset with the amount of longitudinal movement of the drill line for each detectable means that passes said sensor means.

Apparatus for displaying the total depth of an object supported in a well bore by a cable line reeved around at least one sheave means supported on a mast including:

• movement measuring means for sensing the amount and direction of movement of the cable line around the sheave means said movement measuring means including:
• detectable means mounted at equally spaced circumferential positions on the sheave means;
• and
• sensor means for responding to each said detectable means to signal rotation and direction of the sheave means;
• totalizer means including computer means capable of being preset and having memory for displaying the total depth of the object;
• transmission means for transmitting the signal from said sensor means to said totalizer means only when the weight of the object supported by the cable line exceeds the predetermined amount and for interrupting the transmission of the signal from the sensor means to said totalizer means only when the weight of the object supported by the cable line is less than a predetermined amount;
• means for bypassing said transmitting means when it is desired to move the cable line a predetermined longitudinal amount so that said movement measuring means remains coupled to transmit signals to said totalizer means as an indication of the number of detectable means sensed by said sensor means during such predetermined cable line longitudinal movement;
• and
• means for instrumentally noting on said totalizer means the number of signals sensed by said sensor means during such predetermined cable line longitudinal movement as an indication of the amount of longitudinal travel of the cable line for each detectable means whereby said computer means may be preset with the amount of longitudinal travel of the cable line for each detectable means that passes said sensor means.