Downhole pressure gauge converter

• US 5,499,533 A
• Filed: 08/26/1992
• Issued: 03/19/1996
• Est. Priority Date: 08/26/1992
• Status: Expired due to Fees

• Current Assignee: Mark J. Miller, Thomas Allen Miller
• Original Assignee: Mark J. Miller, Thomas Allen Miller
• Inventors: Miller, Mark, Miller, Thomas W.
• Primary Examiner(s): Chilcot, Jr., Richard E.
• Assistant Examiner(s): FELBER, JOSEPH LEON
• Application Number:
  US07/935,860
• Time in Patent Office: 1,301 Days
• Field of Search: 73/151, 73/151.5, 73/152, 73/153, 73/155, 73/734, 346/33 TP, 346/33 WL, 338/40
• US Class Current: 73/152.51
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: G01L 9/0027 using variations in ohmic resistance

Abstract

The apparatus disclosed is a type of downhole pressure gauge to be used to measure and record pressure information about oil and gas wells. The apparatus measures fluctuations in pressure by means of a mechanical pressure sensitive device, such as a Bourdon tube, and records and stores this information by converting mechanical movement, associated with pressure changes as detected by the mechanical pressure sensitive device, into corresponding voltage changes across a potentiometer which are stored in an electronic memory board. The change in voltage over time corresponds to the change in well pressure over time, thereby providing important information to the well operator. Also disclosed is a method for measuring well pressure by means of combining a mechanical pressure sensitive device with an electrical system and an electronic memory board for storing the measurements. Also disclosed is a kit, whereby an existing downhole mechanical pressure gauge can be converted to a mechanical/electrical combination by the replacement of certain parts.

Claims

1. A downhole pressure gauge for wells to provide measurement and recordation of the pressure and fluctuations thereof over time, comprising:

A mechanical pressure sensitive device;

A connecting pin linking the mechanical pressure sensitive device to a potentiometer in such a manner that fluctuations in well pressure as detected by the mechanical pressure sensitive device are converted into rotational changes in the connecting pin and thence into corresponding voltage changes across the potentiometer;

An electronic memory board connected to the potentiometer and capable of detecting and storing the voltage changes and expressing them as a function of time;

An electrical power source electrically connected to the potentiometer and electronic memory board;

A housing containing the above components.

2. The apparatus of claim 1 wherein the housing can be broken down into a plurality of parts, the first part of which contains the mechanical pressure sensitive device and connecting pin, and the second part of which contains the potentiometer, electronic memory board, and power source.

3. The apparatus of claim 2 wherein the first part and second part are threadedly connected together.

4. The apparatus of claim 2 wherein a removable sleeve or adapter is placed on the end of the connecting pin before the first part and second part are joined, the removable sleeve or adapter mating the connecting pin to the potentiometer.

5. The apparatus of claim 1 wherein the connecting pin is linked to the potentiometer by means of a removable sleeve or adapter which fits on the connecting pin and mates it to the potentiometer.

6. The apparatus of claim 1 wherein the mechanical pressure sensitive device is a Bourdon tube.

7. A method of obtaining measurement and recordation of well pressure, comprising:

(a) Providing a housing having a mechanical pressure sensitive device, a connecting pin, a potentiometer, an electronic memory board and an electrical power source;

(b) Providing means for the housing to be lowered into a well bore for the length of time pressure testing is desired;

(c) Measuring the fluctuation of the pressure of the well over time by the mechanical pressure sensitive device, translating the measurements by way of rotational movement of the connecting pin into proportional voltage changes across the potentiometer, and storing the measurements in the electronic memory board;

(d) Retrieving the housing from the well bore and obtaining the results of the measurements as stored on the electronic memory board.

8. A method of obtaining measurement and recordation of well pressure, comprising:

(a) Providing a housing having a mechanical pressure sensitive device, a connecting pin, and a potentiometer;

(b) Providing an electronic memory board and an electrical power source which are remotely connected by wire to the potentiometer in the housing;

(c) Providing means for the housing to be lowered into a well bore for the length of time pressure testing is desired;

(d) Measuring the fluctuation of the pressure of the well over time by the mechanical pressure sensitive device, translating the measurements by way of rotational movement of the connecting pin into proportional voltage changes across the potentiometer, and storing the measurements in the remotely located electronic memory board.

9. In a downhole pressure gauge for wells including a housing containing a mechanical pressure sensitive device with connecting pin linked to a stylus and a mechanical recording unit and clock, wherein the improvement comprises the replacement of the stylus, mechanical recording unit and clock with a potentiometer fitted to receive the connecting pin, said potentiometer being connected to an electronic memory board and a electric power source, all to be contained in the housing.

10. A kit of parts for improving conventional downhole mechanical pressure gauges for wells by replacing certain parts in such gauges, comprising:

(a) A stylus convertor block to attach to the connecting pin from the mechanical pressure sensitive device of the downhole mechanical pressure gauge; and

(b) A potentiometer body with a recess designed to receive the stylus convertor block; and

(c) An electronic memory board to store voltage fluctuations across the potentiometer body; and

(d) An electric power source; and

(e) A housing of such size and shape to allow it to hold the potentiometer body, electronic memory board, and electric power source, and to allow it to function as a component part of a conventional downhole mechanical pressure gauge.

11. The kit of claim 10 wherein the potentiometer body, electronic memory board, and electric power source are contained in a convertor holder which can fit within the conventional downhole mechanical pressure gauge after certain parts in such gauge have been removed.