Apparatus and Method for Opening and Closing an Automatic Valve Installed in the Discharge Line of an Oil Well
The invention relates to an apparatus and a method for opening and closing an automatic valve installed in the discharge line of an oil well, characterized by the installation and setup of the apparatus which controls an automatic valve, which is installed in the discharge line of the casing pipes of an oil well. In said oil well a progressive cavity pump system (PCP) has been installed, which pumps the hydrocarbon to the storage tank through the production pipe, said system maintaining the level of hydrocarbon inside the well for improved production. The apparatus to be installed in the oil well consists of three pressure transmitters, which are placed in the discharge lines of the production pipes, casing pipes and in the discharge line going into the storage tank near the well. In addition, in the storage tank, a radar-type level transmitter is installed to keep monitoring the production from the oil well. In the progressive cavity pump engine (PCP) an inductive proximity sensor is installed to monitor the functioning of the PCP pump. All of the transmitters and the inductive sensor are connected to a cabinet which contains the equipment which registers and records the operation of the system, with a system of batteries and recharges by means of solar panels. The method consists mainly of initially characterizing the behavior of the pressures of the well and the production of hydrocarbon during a period of time, analyzing the data and being able to determine a higher or lower configuration of the pressure in the casing pipes, in order to obtain a greater oil production reflected in the level of the tank. Once the operating pressures to be maintained in the casing pipes are determined, the equipment for the automatic valve to automatically open and close is set up to maintain said pressure and thus obtain a higher level of production of hydrocarbon in the storage tank.
This invention relates to an apparatus which automatically opens and closes an automatic full bore valve, installed in the discharge line coming from the casing pipes (CP) of an oil well without a packer with an artificial lift system housed in the production tubing (PT), based on a progressive cavity pump system (PCP) or mechanical pump (MP), triggered by a smart actuator based on gauging the pressures in the casing pipes (CP) and programming the apparatus, with the purpose of improving the exploitable level of liquid hydrocarbons in oil wells, through draft control of the hydrocarbon by the associated gas from the bottom of the oil well to the surface through the casing pipes (CP), where the pressure is automatically gauged and controlled with the valve's opening and closing process.
INVENTION BACKGROUNDOil wells with a content of associate gas but where the hydrocarbon does not flow through the production tubing (PT) are known as non-flowing wells, which require having a pump in their production tubing (PT) to raise the oil to the collection tanks on the surface, such as a progressive cavity pump (PCP) or mechanical pump (MP) for extracting said hydrocarbon from the bottom of the oil well. Gas is released in the annular space between the production tubing (PT) and the casing pipes (CP) causing an increase in pressure in said casing pipes (CP), which affects the well's production capacity because the fluids located in said casing pipes (CP) settle according to their density and the gas ends up in the upper portion and the fluids under the gas, which on occasions their level is located at a depth lower than the location of the progressive cavity pump (PCP) or mechanical pump (MP) installed on said production tubing (PT), which prevents an efficient extraction and production of hydrocarbons in the oil well.
This innovative apparatus was developed in order to solve the aforementioned problems, which allows for the hydrocarbon level in an oil well with an artificial PCP or MP (progressive cavity pump or mechanical pump) system to remain above said pump, improving the hydrocarbon production in the oil well.
This problem of maintaining the hydrocarbon level in the oil well above the location of the progressive cavity pump (PCP) or mechanical pump (MP) installed (only one pump type may be installed) is achieved with a controlled regulation of the pressure in the annular spaces of the CP (casing pipes) by opening and closing an automatic valve, using an apparatus called recorder-controller, which monitors the variables in pressure and the oil level in the oil well.
The characteristic details of this innovative invention are clearly described in the following description and in the attached drawings, which are intended to be illustrative but not limited thereto.
Additionally, three manometric pressure transmitters (5, 6 and 7) are installed: one in the 2⅜-in diameter casing pipe discharge line (8), another one in the 2⅜-in diameter production tubing discharge line (18), and one more in the 2⅜-in diameter discharge line to the production tank (19). A radar level transmitter (10) is installed on top of the oil production storage tank (9). Sensor electrical conduits (11) are used for connecting the control cabinet (13) to the inductive proximity sensor (17) with an 18 AWG 3 conductor aluminum shielded cable; the manometric pressure transmitters (5, 6 and 7) and the level transmitter (10) with a heavy duty 14 AWG 2 conductor cable. Likewise, the automatic valve (2) is connected with a multi conductor 16 AWG 4 conductor cable to the control cabinet (13) through the valve electrical conduit (12). Said control cabinet (13) is installed on a pole (15) made with a 4-inch steel channel, anchored on the ground to a concrete base (16) measuring 40 centimeters long, 40 centimeters wide and 10 centimeters tall. Located on top of the control cabinet (13) and also supported by the post (15), a 12-VDC, 20-Watt solar panel (14) made up by 2 serial photocells is used for recharging some batteries inside the control cabinet (13) to feed the whole system with direct current, including the revolutions sensor (17), pressure transmitters (5, 6 and 7), level transmitter (10) and automatic valve (2).
Said automatic valve (2) is made of stainless steel in order to avoid corrosion and has an inlet (20) and an outlet (21) of 2 inches in diameter on each side, and that is where said casing pipes (8) are connected as described in
The recorder-controller device (35) is connected to the radar level transmitter (10), to the inductive proximity sensor (17) and to the manometric pressure transmitters (5, 6 and 7), all described in
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- 1) +24V: Positive power input.
- 2) +VT: Positive power output to the devices with HART-communication protocol.
- 3) +W: Positive power output to the automatic valve.
- 4) CIE: Positive control output to execute the closing of the automatic valve.
- 5) AP: Positive control output to execute the opening of the automatic valve.
- 6) GND: Circuit's negative (3 terminals amongst themselves).
The main function of this apparatus consists in opening and closing the automatic valve (2) installed in the casing pipe discharge line (8), with the purpose of controlling the increase and decrease in pressure in said line coming from the oil well (1), staying within a certain range (highest and lowest) previously established and programmed in the recorder-controller device (35). Said pressure in the casing pipes (8) is received in the recorder-controller device (35), by the manometric pressure transmitter's (5) measurement installed on said casing pipes (8), and where a software in the recorder-controller device (35) monitors the pressure. Opening or closing of the automatic valve (2) is activated based on pressure values that have been previously set up in said recorder-controller device (35): it opens if the pressure goes over the highest value set and it closes if it goes under the lowest pressure set. Initially and prior to setting up the highest and lowest pressure to be controlled in the casing pipes (8), the pressures obtained by the manometric pressure transmitters (5, 6 and 7) installed on the casing pipe discharge line (8), on the production tubing discharge line (18) and on the discharge line to the production tank (19), respectively, are monitored and analyzed, as well as the data from the level transmitter (10) installed in the production tank (9) is analyzed. Said analysis is carried out by collecting information from the pressure transmitters (5, 6 and 7) and level transmitter (10), operating the automatic valve (2) for six days as programmed, in various open and close positions, this way achieving a characterization as to in what pressure ranges in the casing pipes (8) and the behavior shown in the pressures in the production tubing (18) and in the discharge line to the tank (19), a greater increase in the production storage tank (9) is obtained in eight-hour periods of time. The inductive proximity sensor (17) installed on top of the progressive cavity pump (3) motor indicates when the pump is in operation, this way discarding possible errors in production measuring in the event the oil well (1) is not producing any hydrocarbon; that is, if the pump is not operating, it is going to be very difficult to trust the pressure characterization, unless this is a naturally-flowing oil well.
The object of this system is to establish a method to maximize the production of hydrocarbon in the oil well (1) through the following steps:
1. Installing the apparatus described in
2. Prior to the autonomous operation of the automatic valve (2) the apparatus is programmed to collect information on the operation of the oil well (1) with the pressure transmitters (5, 6 and 7), level transmitter (10) and inductive sensor (17) for six days in a row, opening the automatic valve (2) initially 15% on the first day and increasing by 15% each day until reaching 100% and/or six days of operation. The information is recorded by the recorder-controller device (35) to be analyzed later, and is as follows:
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- a) Date. Format: dd/mm/yy.
- b) Data recording time. Format: hh:mm.
- c) Progressive cavity pump operation indicator. 1=In operation, 0=Stopped. Data is not recorded in the recorder-controller device (35) if the progressive cavity pump is not in operation as determined by the inductive proximity sensor (17).
- d) Pressure in the casing pipe discharge line (8) in PSI units.
- e) Pressure in the production tubing discharge line (18) in PSI units.
- f) Pressure in the discharge line to the production tank (19) in PSI units.
- g) Opening percentage of the automatic valve (2) in function of the voltage applied to the actuator.
- h) Tank level of the production storage tank (9) in lineal meters (m).
- i) Tank level in cubic meters (m3). This is calculated from the tank dimensions by multiplying the tank's area by the level in meters.
- j) Tank level in cubic meters (Barrels). This is calculated from the level in cubic meters (m3) divided by 0.159 m3 which is the equivalent of one barrel of 159 liters equals 0.159 m3 (1 m3 equals 1,000 liters).
3. The information stored in the recorder-controller device (35) is recovered with a portable computer through the USB port (49), the data is transferred to an Excel worksheet, and the following information is added to each record saved:
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- a) Conversion of the production storage tank (9) level from centimeters to m3 according to the dimensions of said tank.
- b) Conversion of the production storage tank (9) level from Barrels (bbl) according to the dimensions of said tank.
4. The pressures recorded in the casing pipes (8) and production tubing (18) are plotted on a graph.
5. The levels of the production storage tank (9) in Barrels are recorded during the data collection period.
6. The maximum and minimum pressures of best operation in the casing pipe discharge line (8) are determined by using and analyzing the graphs, where the highest level of hydrocarbon production is shown in the storage tank (9).
7. The recorder-controller device (35) is set up for the automatic valve (2) to operate autonomously, with the highest and lowest pressure values to be controlled in the casing pipes (8), obtained with the prior data depicted by the whole system operating for six days.
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- PT measuring 2⅜ inches in diameter (79) with 433.20 lineal meters in depth. The production tubing discharge line (18) is connected to the PT.
- Outer CP measuring 9⅝ inches in diameter (8) with 51 lineal meters in depth.
- Inner CP measuring 7 inches in diameter (81) with 290 lineal meters in depth. The casing pipe discharge line (8) is connected to this CP on the surface.
As shown in Tables 1 and 2, the data is recorded each second showing the columns with the information described above in step number 2 of the objective of this system. It is worth pointing out that that Table 2 shows 2 columns which are Level (m3) and Level (bbl) which are calculated based on the tank's dimensions from the column Level (m), data which is sent by the level transmitter (10) installed in the production storage tank (9). The dimensions of said tank are 3.50 meters in diameter and 4.80 meters in height, so the area of said tank is 9.62 m2, which is multiplied by the Level (m) resulting in the value for column Level (m3). The value of column Level (bbl) is obtained by dividing the column Level (m3) by the equivalent of 1 oil barrel which is 0.159 cubic meters (1 barrel equals 159 liters and equals 0.159 cubic meters).
By analyzing the data in this graph in
The decision making process in order to set up the autonomous operation of the automatic valve (2) is centered on the pressures in the casing tubing discharge line (84), which is what represents the variation in pressure which modifies the hydrocarbon production, maintaining the level of said hydrocarbon in the oil well (1), obtaining a greater amount of barrels with the progressive cavity pump (PCP). The pressure in the production tubing discharge line (85) is maintained constant without any variation, without any dependency on the hydrocarbon production as it is seen in the description of
The correlation of Graphs 17 and 18, where the pressures in the casing pipe discharge line (8) are compared to the production storage tank (9) levels, establishes the method to determine the lowest and highest pressure range to be set up in the recorder-controller device (35). The opening of the automatic valve (2) is initially set up to open at 50%, this way allowing for the whole autonomous system to regulate the pressures between 395.848 PSI established as the lowest pressure and 439.764 PSI established as the highest pressure, while variations over and under said pressures may occur, considered as part of the normal adjustments made by the apparatus during its operation. The pressure transmitter (5,
The total period of time graphed in this
The range of data in Table 5 cannot be clearly appreciated in the graph of this
Claims
1. An apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, which comprises:
- a) One discharge line (8) connected to the casing pipes of an oil well, one discharge line (18) connected to the production tubing of an oil well, and interconnection of said 2 discharge lines to one single discharge line (19) to one storage tank (9) near the well.
- b) One stainless steel automatic valve (2), 2 inches in diameter, with a 24-volt electric actuator, connected in the casing pipe discharge line (8).
- c) Three pressure transmitters (5, 6 and 7) with a port for data input and transmission, 24 volts and HART-communication protocol installed: one in the casing pipe discharge line (8) before the automatic valve (2), another in the production tubing discharge line (18) and the last one in the discharge line (19) to the production tank (9).
- d) One radar level transmitter (10) installed on top of the oil production storage tank (9).
- e) If the oil well is equipped with a progressive cavity pump system (PCP), an inductive proximity sensor (17) installed on top of the motor.
- f) One control cabinet (13) consisting of one recorder-controller device (35), one 24-VDC 5-Amp voltage regulator (36) and two sealed 24-VDC 35-AH rechargeable batteries (37).
- g) One recorder-controller device (35) comprised by one section of the recorder formed by one PIC18F26J50 processor (56), one InLink OEM HART protocol modem (57), one USB cable connector (58) one cable connector (59), one 2 GB SD memory card (61), one 270Ω/1 W resistor (62) and one 5 KΩ resistor; one power supply section formed by two LM317 linear regulators (65), two 1 KΩ precision potentiometers (66), one 220 pF capacitor (67), two 200Ω resistors (72) and two 10 pF capacitors (73); and a controller interface section formed by one Latch 74LS573 integrated circuit (68), two 24 V coil relays (69), two TIP41C transistors (70), two 5 KΩ resistors (75) and two 1 Amp semiconductor diodes (76).
2. The apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 1 a), wherein the 3 discharge lines are 2⅜ inches in diameter.
3. The apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 1 f), wherein the control cabinet (13) is held by a pole (15) made with a 4-inch steel channel, anchored on the ground to a concrete base (16) measuring 40 centimeters long, 40 centimeters wide and 10 centimeters tall.
4. The apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 3, wherein a 12-VDC, 20-Watt solar panel (14) made up by 2 serial photocells connected to the voltage regulator (36) inside the control cabinet (13) is located on top of the post (15).
5. The apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 1, wherein the automatic valve (2) is connected with a multi conductor 16 AWG 4 conductor cable to the control cabinet (13) through the valve electrical conduit (12).
6. The apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 1, wherein the pressure transmitters (5, 6 and 7), level transmitter (10) are connected to the control cabinet (13) with a heavy duty 14 AWG 2 conductor cable.
7. The apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 1, wherein the inductive proximity sensor (17) is connected to the control cabinet (13) with an 18 AWG 3 conductor aluminum shielded cable.
8. A method for opening and closing an automatic valve installed in the discharge line of an oil well, comprising the following steps:
- a) Providing and installing the apparatus described in claim 1.
- b) Placing in operation the apparatus with an initial programming and setup in order to collect preliminary information on the oil well (1), with the pressure transmitters (5, 6 and 7) and level transmitter (10) for six days in a row, gradually opening the automatic valve (2) during said period of time.
- c) Recovering the data recorded on the oil well (1) with a portable computer connected to the recorder-controller device (35) through the USB port (49).
- d) Transferring the data recovered from the recorder-controller device (35) to a spreadsheet.
- e) The date and time when the data and pressures (PSI) recorded in the casing pipe discharge line (8) and in the production tubing discharge line (18) are plotted on a graph to better analyze their behavior.
- g) The same date and time when the data described in subparagraph e) above are plotted on a graph with the data on the level in barrels (bbl) as recorded in the storage tank (9).
- h) The minimum and maximum pressures in the casing pipe discharge line (8) achieving a stable increase in hydrocarbon as reflected by the level in the storage tank (9) are determined based on the analysis made from the data and graphs.
- i) The recorder-controller device (35) is set up with the minimum and maximum pressure values as determined in subparagraph g) above, in which the pressure must be maintained in the casing pipe discharge line (8) by opening and closing the automatic valve (2) in an autonomous fashion.
9. The method for opening and closing an automatic valve installed in the discharge line of an oil well, according with claim 8 b), wherein the initial programming for collecting information on the operation of the oil well (1) is carried out in the recorder-controller device (35).
10. The method for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 7 b), wherein during the period for collecting data on the oil well (1) for six days, the automatic valve (2) is programmed to open gradually starting at 15%, gradually increasing until reaching 100% open.
11. The method for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 7 c), wherein the data recorded in the recorder-controller device (35) and which is transferred to the portable computer is: date, time, operation status of the progressive cavity pump (PCP), pressure in the casing pipe discharge line, pressure in the production tubing discharge line, pressure in the discharge line to the production tank, automatic valve's opening percentage, storage tank level in linear meters, and two columns with the calculation of the storage tank level in cubic meters and barrels according to its dimensions, based on the level in linear meters.
12. The method for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 7 g), wherein the minimum and maximum pressure values are established by analyzing the correlation between graph line (96) for the pressure in the casing pipes (8) and the graph line (102) for the level in the storage tank (9), within the ranges of highest stable increase in the hydrocarbon production.
13. An apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 7 h), wherein the automatic valve (2) closes in order to increase the pressure in the casing pipe discharge line (8) and opens in order to decrease it.
14. An apparatus for opening and closing an automatic valve installed in the discharge line of an oil well, according to claim 7 h), wherein the pressure in the casing pipe discharge line must be maintained within the set maximum and minimum pressure values, but during its operation it may exceed said ranges over and under.
Type: Application
Filed: Jan 18, 2013
Publication Date: Dec 25, 2014
Inventor: Vicente Gonzalez Davila (Madero)
Application Number: 14/371,633
International Classification: E21B 41/00 (20060101); E21B 43/12 (20060101); E21B 47/06 (20060101); E21B 34/02 (20060101);