US20140374090A1

US20140374090A1 - Apparatus and Method for Opening and Closing an Automatic Valve Installed in the Discharge Line of an Oil Well

Info

Publication number: US20140374090A1
Application number: US14/371,633
Authority: US
Inventors: Vicente Gonzalez Davila
Original assignee: Geo Estratos de C V SA
Current assignee: Geo Estratos de C V SA
Priority date: 2012-02-10
Filing date: 2013-01-18
Publication date: 2014-12-25
Also published as: CA2861218A1; MX2012001757A; WO2013119099A1; MX346417B

Abstract

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.

Description

INVENTION PURPOSE

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 BACKGROUND

Oil 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.

INVENTION DESCRIPTION

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.

FIG. 1 shows the general schematics of the installation of the elements comprising the apparatus for opening and closing the automatic valve in an oil well with an artificial lift system (ALS) called progressive cavity pump (PCP).

FIG. 2 shows the 2-inch stainless steel automatic valve with 24-volt direct current (VDC) electric actuator.

FIG. 3 depicts the inductive proximity sensor utilized for calculating the revolutions per minute (RPM) of the progressive cavity pump (PCP).

FIG. 4 shows the base used for the inductive proximity sensor and which is installed on the progressive cavity pump (PCP) surface equipment.

FIG. 5 shows the manometric pressure transmitters used in the apparatus, with stainless steel casing and 10.5 to 45 VDC feed.

FIG. 6 shows the radar level transmitter installed on the oil production storage tank.

FIG. 7 shows the cabinet where the apparatus's control system is located.

FIG. 8 shows an outside top view of the recorder-controller device.

FIG. 9 shows an outside bottom view of the recorder-controller device.

FIG. 10 shows the recorder-controller device and its internal components provided with a computerized system.

FIG. 11 describes the components of one of the 2 sections of the recorder-controller device, called recorder section.

FIG. 12 shows the schematics for the recorder circuit of the recorder-controller device's recorder section.

FIG. 13 describes the components of the recorder-controller device's controller interface section and power supply.

FIG. 14 shows the schematics for the power supply circuit of the recorder-controller device's controller interface section and power supply.

FIG. 15 shows the schematics for the controller interface circuit of the recorder-controller device's controller interface section and power supply.

FIG. 16 generally depicts the mechanical state of an oil well in which this invention's method is being applied.

FIG. 17 shows a graph of this invention's method and apparatus being used, with pressure data obtained during the characterization prior to the configuration for the automatic valve's autonomous operation.

FIG. 18 shows a graph with the production data in oil barrels resulting from the application of this invention's method and apparatus, during the characterization period prior to the configuration for the automatic valve's autonomous operation.

FIG. 19 shows the pressure graph in the discharge lines of an oil well operating the complete system configured automatically.

FIG. 20 shows the oil well's production levels graph in barrels, with the complete system working automatically.

FIG. 1 illustrates the general schematics for the installation of apparatus for opening and closing, where the automatic valve installation (2) is shown placed in the casing pipe discharge line (8). The oil well (1) has a 2⅞-inch blow out preventer (BOP) (4) to prevent spills due to an increase in pressure, and an artificial lift system (ALS) with the surface motor and equipment of a progressive cavity pump (PCP) (3) installed on top of said oil well (1). An inductive proximity sensor (17) is located on top of the progressive cavity pump's motor and equipment (3) which is used for calculating the revolutions per minute (RPM) of the progressive cavity pump (PCP).
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).
FIG. 2 describes the automatic valve (2) used in the apparatus, which is installed, as described in FIG. 1, in the casing pipe discharge line (8).
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 FIG. 1. The automatic valve (2) has a 24-Volt direct current electric actuator on top (22) to open and close it, connecting the power cables to the side ports (23) as shown in said FIG. 2. The function of said automatic valve (2) is to control the outflow of the gas found in the casing pipe discharge line (8) described in FIG. 1.
FIG. 3 describes the sensor utilized to obtain the revolutions per minute (RPM) of the progressive cavity pump (PCP). The sensor used is an inductive proximity sensor (17), which is utilized to detect objects within a specific range of operation. The RPM count is made in the control cabinet apparatus (13) by transmitting the information via the sensor connecting cable (24), which is connected through the sensor electrical conduits (11) described in FIG. 1. Said inductive sensor (17) requires a voltage feed of 24 volts direct current, with a measuring range of 8 to 20 mm. The sensor's diameter is 30 mm.
FIG. 4 depicts the base for installing the inductive proximity sensor (17) described in FIGS. 1 and 3. Said sensor requires a mounting base (25) made of steel and which is used with the purpose of having a proper support for said inductive proximity sensor (17), which is attached by two nuts (26).
FIG. 5 describes the manometric pressure transmitters (5, 6 and 7), which are used/in the opening and closing apparatus, and which are the same type and model. Said pressure transmitters (5, 6 and 7) model number STK131, are a ceramic sensor with a port for data input and transmission (27), 24 volts direct current and HART-communication protocol, with a ½-inch NPT connection to the pipe (26) where it is screwed in and fastened, with a stainless steel outer casing (28) and process connection (29). The pipes where said pressure transmitter are installed as described in FIG. 1, are the casing pipe discharge line (8), production tubing discharge line (18), and discharge line to the production tank (19).
FIG. 6 shows in detail the radar transmitter (10) mentioned in the description of FIG. 1, which is connected to the control cabinet (13) by a heavy duty 14 AWG 2 cable which goes through the sensor electric conduit (11), and goes into the level sensor connecting cable port (31). Additionally, inside the oil storage tank (9) and connected to the radar level transmitter (10) the level sensor antenna is mounted which emits signals to determine the level of the tank. Said information is sent to the apparatus installed inside the control cabinet (13) to be processed.
FIG. 7 describes the control cabinet (13), which is made of galvanized sheet metal material with epoxy paint measuring 50×40×21 centimeters, and has a door (33) that opens in order to install the apparatus and cables inside, which has 2 locks (34) to be opened and closed with a key. The recorder-controller device (35), a 24-VDC 5-Amp voltage regulator (36) and 2 sealed 24-VDC 35-AH rechargeable batteries (37) are installed inside said control cabinet (13). The voltage regulator (36) is connected to the photocell solar panel (14) described in FIG. 1, to the recorder-controller (35) and to the sealed rechargeable batteries (37) using heavy duty 14 AWG×2 C cable (41, 42 and 43). The function of said voltage regulator (36) is to regulate the voltage coming from the solar panel (14) to the batteries (37) to prevent overcharging them and at the same time supply power to the recorder-controller (35). The sealed rechargeable batteries (37) are connected in series by a cable (38) forming a 24-VDC 35-AH battery bank.
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 FIG. 1, by the sensor connecting cables (39). Additionally, said recorder-controller (35) is connected to the automatic valve (2) by a with a multi conductor 16 AWG 4 conductor cable (40). The cables coming out from the recorder-controller (35) to the radar level transmitter (10), to the proximity sensor (17) and to the manometric pressure transmitters (5, 6 and 7) go inside a sensor electric conduit (11) described in FIG. 1. Likewise, the cables coming out of the recorder-controller (35) to the automatic valve (2) go inside the valve electric conduit (12), described in FIG. 1.
FIG. 8 shows an outside top view of the recorder-controller device (35), which shows an LF LED (44) which when on indicates that the device is in reading mode and data recording, an LV LED (45) which when on indicates that the automatic valve (2) described in FIG. 2 is in operation, an LH LED (46) which when on indicates that the HART communication with the sensors is in progress, a 2-step switch (47) which function is to configure the recorder's operation mode, which is reading or recording, a reset button (48) to reset the recorder and a USB port (49) used for transferring the data recorded in the recorder-controller device (35) to a laptop.
FIG. 9 shows an outside bottom view of the recorder-controller device (35), which has an INTENC switch (50) for turning the device on and off, a LEDENC LED (51) where one can identify if the device is in operation (turned on), and it additionally has a connection panel (52) where the following are connected from left to right:

- 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).

FIG. 10 depicts the internal components of the recorder-controller device (35), which is divided in 2 sections: the recorder section (53) and the controller interface and power supply section (54). Both sections are connected by 3 cables (55) which are used to carry current for the circuits in the recorder section and for the automatic valve control (2) described in FIG. 2, from the controller interface and power supply section (54). FIGS. 11 and 12 describe in detail said sections of the device.
FIG. 11 depicts in more detail the recorder section (53) of the recorder-controller device (35). Said section shows in addition to the description in FIG. 8, the PIC18F26J50 processor (56), the InLink OEM HART protocol modem (57), the USB cable connector (58) coming from the USB port (49) and the cable connector (59) which receives the three cables (55) coming from the controller interface and power supply section (54) described in FIG. 10. The function of the InLink OEM HART protocol modem (57) is to receive information from the manometric pressure transmitters (5, 6 and 7) and the level transmitter (10) described in FIG. 1. Said information collected from the transmitters via the HART protocol modem (57) is sent to the controller interface and power supply section (54) to be processed, which is described below in FIG. 13.
FIG. 12 illustrates the recorder section (53) but in the form of a schematic diagram of the circuit, where it is possible to see in a single plane components not observed in the description in FIG. 11. The diagram shows the PIC18F26J50 microprocessor (56), the InLink OEM HART protocol modem (57) and the output schematics to the USB port (49). Additionally, it illustrates the 2 GB SD memory card (61), the HART protocol modem (57) output to the pressure transmitters (5, 6 and 7) and the level transmitter (10), the 270Ω/1 W resistor (62), the 5 KΩ resistor and the microprocessor output (56) to the controller interface and power supply section (54). The function of this section of the recorder (53) is to store the data from the pressure transmitters (5, 6 and 7) and the level transmitter (10) described in FIG. 1, primarily to analyze the data on the oil well (1) and secondly to configure by programming the controller interface section (54), so that, based on the data obtained online, opening and closing of the automatic valve (2) described in FIG. 1 is placed in operation by analyzing the pressures in the casing pipes (8), in the production tubing (18) and in the discharge line to the production tank (19), and the oil level in the oil production storage tank (9). This operation of the automatic valve (2) in a configured fashion will allow for keeping the hydrocarbon levels in the oil well above the progressive cavity pump, maintaining the oil well (1) in a continuous production by keeping optimum operation pressures. The analysis of the information on the operation (pressures and tank level) of the oil well (1) is carried out because the 2 GB SD memory card (61) stores said information, and it is extracted through the USB port (49) to a computer for data analysis in graphic form.
FIG. 13 shows the controller interface and power supply section (54). Said section is comprised by two circuit schematic diagrams: the power supply (FIG. 14) and the controller interface (FIG. 15). This FIG. 13 depicts some of the components, such as: two LM317 linear regulators (65), two 1 KΩ precision potentiometers (66), one 220 pF capacitor (67), one Latch 74LS573 integrated circuit (68), two 24 V coil relays (69) and two TIP41C transistors (70).
FIG. 14 depicts one of the circuit schematic diagrams of the recorder-controller device (35), called power supply circuit (71) which is located in one of the sections (54) of said device. The purpose of the power supply circuit (71) is to describe the control in order to supply power in volts to the whole system in the recorder-controller device (35) for the proper operation thereof. At the same time, said voltage power supply comes from the voltage regulator (36) described in FIG. 7. The components comprising the power supply circuit (71) are: 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).
FIG. 15 describes another circuit schematic diagram of the recorder-controller device (35) called controller interface circuit (71) which is located in one of the sections (54) of said device. The function of this controller interface circuit (74) is to open and/or close the automatic valve (2) by the activation of its actuator (77), in order to maintain a certain range of pressures in the oil well (1) (closed system), and where said pressures were established in the program stored in the recorder-controller device (35), based on production tests previously performed at said well, and said production was corroborated by the level transmitter (10) mounted on the oil production storage tank (9), where an increase in the amount of oil (tank level) extracted from the oil well (1) can be validated. The components comprising the controller interface circuit (74) and subject of this FIG. 15 description are: 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).
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 FIG. 1 and all of its components comprising it described in FIG. 2 to FIG. 15, at the oil well (1).
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:

- 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:

- 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.
FIG. 16 describes an oil well (1) generally showing its components in the area below the ground surface (78), known as wellbore. The operation data describing the method of this invention is an oil well (1) with certain physical characteristics, but please note that the apparatus and method can operate on any type of oil wells, including natural-flowing wells. The oil well (1) wellbore is as follows:

- 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.

FIG. 17 depicts a graph showing the pressure data in the casing pipe discharge line (8) and in the production tubing discharge line (18) obtained by the pressure transmitters (5, 6), showing all the data records obtained from an oil well with a progressive cavity pump, with the apparatus installed as described in FIG. 1 and FIG. 16. Tables 1 and 2 show some of the records with the data obtained from the recorder-controller device (35) that were plotted on a graph. These records (date and time) are divided in two tables in order to show all columns of the data being recorded. Not all data is shown in Tables 1 and 2 because there are about 7,770 records or lines, and Table 1 does not show a column for the operation indicator of the progressive cavity pump (PCP) as recorded by the inductive proximity sensor (17) because the pump was in operation for all records analyzed.

TABLE 1

Part 1 of the data obtained by the
recorder-controller device

		CASING	PRODUCTION	TANK
	TIME	PIPES	TUBING	DISCHARGE
DATE	(Hrs)	(PSI)	(PSI)	TUBING (PSI)

Apr. 13, 2011	15:13	147.422	12.872	5.942
Apr. 13, 2011	15:14	147.363	12.872	6.882
Apr. 13, 2011	15:15	147.298	12.872	6.882
Apr. 13, 2011	15:16	147.227	12.872	6.882
Apr. 13, 2011	15:17	147.157	12.872	6.882
Apr. 13, 2011	15:18	147.100	12.872	6.882
Apr. 13, 2011	15:19	147.082	12.872	6.882
Apr. 13, 2011	15:20	147.024	12.872	6.882
Apr. 13, 2011	15:21	147.000	12.872	6.882
Apr. 13, 2011	15:22	146.975	12.872	6.882
Apr. 13, 2011	15:23	146.966	12.872	6.882
Apr. 13, 2011	15:24	146.930	12.872	6.882
Apr. 13, 2011	15:25	146.928	13.781	6.882
Apr. 13, 2011	15:26	146.894	13.781	6.882
Apr. 13, 2011	15:27	146.888	13.781	6.882
Apr. 13, 2011	15:28	146.874	12.872	6.882
Apr. 13, 2011	15:29	146.854	12.872	6.882
Apr. 13, 2011	15:30	146.841	12.872	6.882
Apr. 13, 2011	15:31	146.841	12.872	6.882

TABLE 2

Part 2 of the data obtained by the
recorder-controller device

		VALVE
	TIME	OPENING	LEVEL	LEVEL	LEVEL
DATE	(Hrs)	PERCENTAGE	(m)	(m3)	(bbl)

Apr. 13, 2011	15:13	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:14	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:15	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:16	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:17	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:18	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:19	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:20	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:21	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:22	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:23	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:24	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:25	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:26	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:27	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:28	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:29	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:30	10.0	0.83	7.985	50.223
Apr. 13, 2011	15:31	10.0	0.83	7.985	50.223

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 FIG. 17, all records collected by the apparatus can be observed as a whole, where the X-axis (82) shows the date and time of operation of the apparatus and the Y-axis (83) shows the pressure in PSI unites. The graph contains two lines representing the pressure in the casing pipe discharge line (84) and the pressure in the production tubing discharge line (85). Table 3 shows X-axis (82) data where the following dates and times with the approximate opening percentage of the automatic valve are shown:

TABLE 3

Approximate opening percentage at certain
operating date and time during data characterization

	Time	Automatic Valve
Date	(Hrs)	Opening Percentage

Apr. 21, 2011	21:21	15%
Apr. 22, 2011	22:21	30%
Apr. 23, 2011	23:21	45%
Apr. 24, 2011	00:21	60%
Apr. 26, 2011	01:21	75%

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 FIG. 18. Pressure Point 1 (86) which is 395.848 PSI dated Apr. 25, 2011 at 00:21 hrs, and pressure Point 2 (87) which is 439.764 dated Apr. 25, 2011 at 18:40 hrs, both in the pressure graph line for the casing pipes (84), represent the pressure range with a stable increase in hydrocarbon production, as described in FIG. 18 below.
FIG. 18 shows the graph line (90) for the level of the production storage tank (9) on the same dates and times as the pressure graph described in FIG. 17. The X-axis (88) shows the date and time of the measurements taken of the level in said tank and the Y-axis (89) shows the hydrocarbon barrels (bbl). This Graph 18 shows level Points 1 and 2 (91, 92), which correspond to the same pressure Points 1 and 2 (86, 87) described in FIG. 17. Said points correspond to the level Point 1 dated Apr. 25, 2011 at 00:21 hrs measuring 21.663 bbl, and level Point 2 dated Apr, 25, 2011 at 18:40 hrs measuring 73.943 bbl. The measurement in this period of time corresponds to a production of 52.280 bbl, calculated by the difference between the two points. It is important to clarify that the graph shows a drop in the level (93) of the production storage tank (9), which is due to the extraction of hydrocarbon by a tanker truck called PW (Pressure & Vacuum Vehicle), which is carried out periodically to keep the tank from filling and spilling.
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, FIG. 1) installed on the casing pipe discharge line (8) is the one keeping within the established lowest and highest pressure range with the automatic valve's (2) opening and closing control which is carried out by the recorder-controller device (35). This way the lowest and highest pressure is determined, by characterizing the previous information and analyzing it in graphic form.
FIG. 19 shows the graph of the pressures in the casing pipe discharge line (8) and production tubing discharge line (18) with the recorder-controller device (35) that has been set up and programmed at the lowest pressure of 395.84 PSI and at the highest pressure of 439.764 PSI. The automatic valve (2) opens or closes as the pressure increases or decreases in the casing pipe discharge line (8), which is measured by its pressure transmitter (5) and the data is sent to the recorder-controller device (35). The X-axis (94) contains the date and time when the pressures were measured and the Y-axis (95) contains the pressure in PSI measurement unit. The graph line for the pressure in the casing pipes (96) shows the behavior of the configured system in operation, and likewise, the graph line for the pressure in the production tubing (97). Table 4 shows a segment of the data plotted on the graph which is stored in the recorder-controller device (35), where the behavior can be observed as to the pressures due to the adjustments in opening and closing the automatic valve (2) in order to keep them within the lowest and highest range of pressures in the casing pipe discharge line (8). A reflection of the hydrocarbon level in the oil well (1) and the continuous pumping by the progressive cavity pump system (PCP) installed at said well can be observed below in FIG. 20 where the production's behavior can be seen in the storage tank level (9).

TABLE 4

Segment of the pressure records during the
autonomous operation of the automatic valve (2)

		CASING	PRODUCTION	TANK
	TIME	PIPES	TUBING	DISCHARGE
DATE	(Hrs)	(PSI)	(PSI)	TUBING (PSI)

May 4, 2011	19:20	243.590	57.907	52.749
May 4, 2011	19:21	227.567	58.816	52.749
May 4, 2011	19:22	235.971	58.816	53.719
May 4, 2011	19:23	240.703	60.692	54.659
May 4, 2011	19:24	337.522	8.594	4.669
May 4, 2011	19:25	368.261	9.816	2.274
May 4, 2011	19:26	376.996	8.415	2.153
May 4, 2011	19:27	378.846	7.887	1.971
May 4, 2011	19:28	388.574	8.620	2.426
May 4, 2011	19:29	391.423	11.640	6.640
May 4, 2011	19:30	398.599	13.282	6.549
May 4, 2011	19:31	401.320	12.491	4.548
May 4, 2011	19:32	405.998	15.381	7.895
May 4, 2011	19:33	408.087	10.782	6.064
May 4, 2011	19:34	409.520	9.793	4.548
May 4, 2011	19:35	365.846	9.793	4.487

The total period of time graphed in this FIG. 19 corresponds to the range from May 1, 2011 at 16:00 hrs to May 5, 2011 at 16:00 hrs. The graph shows the starting points with the highest control (98, 99) of the automatic valve (2) over the pressure in the casing pipes (8), where in FIG. 20 below can be observed that the hydrocarbon level in the oil well (1) starts to be kept constant with an increase in level in the storage tank (9), by opening the automatic valve (2) in order to decrease the and opening it to increase it in said casing pipes (8). This opening and closing control is carried out by the recorder-controller device (35) as programmed and with the help of the whole apparatus installed at the oil well (1).
FIG. 20 shows the storage tank (9) level in barrels (bbl), in the same date and time period as the pressures plotted on the graph in FIG. 19 above. This way the effect of the automatic valve (2) operating autonomously may be correlated by comparing the pressure control to the increase in level in the storage tank (9). This information shows that the hydrocarbon level in the oil well (1) is kept thanks to the configuration of pressures maintained in the casing pipe discharge line (8), with the opening and closing operation of the automatic valve (2). The X-axis (100) on the graph shows the date and time when the level was measured, which corresponds to the same period of time when the pressures were measured as described in FIG. 19. The Y-axis (101) shows the storage tank (9) level measured in barrels (bbl). The tank level graph line (102) shows an increase in the oil well (1) production, due to the control in pressure in the casing pipe discharge line (8) maintains the level of hydrocarbon in the oil well, thus allowing for a higher pumping through the progressive cavity pump (PCP) installed at said well. This same figure shows a drop in the tank level (103) due to the hydrocarbon having been extracted by a tanker truck, with the purpose of preventing a spill. It is important to point out that the production of hydrocarbon occurs through the production tubing discharge line (18) to the discharge line to the tank (19). Table 5 shows the same data with the date and time as Table 4, but with information about the opening percentage of the automatic valve and the production tank level (9), with the conversions in meters, cubic meters and barrels as described above in the description for Table 2 in FIG. 17.

TABLE 5

Level records segment during the
autonomous operation of automatic pump (2)

VALVE

		OPENING	LEVEL	LEVEL	LEVEL
DATE	TIME	PERCENTAGE	(m)	(m3)	(bbl)

May 4, 2011	19:20	75.0	1.96	18.874	118.707
May 4, 2011	19:21	75.0	1.98	19.048	119.796
May 4, 2011	19:22	75.0	1.99	19.144	120.401
May 4, 2011	19:23	45.0	1.98	19.048	119.796
May 4, 2011	19:24	30.0	1.99	19.144	120.401
May 4, 2011	19:25	30.0	1.99	19.115	120.220
May 4, 2011	19:26	30.0	2.00	19.240	121.006
May 4, 2011	19:27	15.0	2.00	19.240	121.006
May 4, 2011	19:28	15.0	2.00	19.240	121.006
May 4, 2011	19:29	15.0	2.01	19.336	121.661
May 4, 2011	19:30	15.0	2.01	19.336	121.661
May 4, 2011	19:31	15.0	2.00	19.240	121.006
May 4, 2011	19:32	15.0	2.01	19.336	121.661
May 4, 2011	19:33	15.0	2.01	19.336	121.661
May 4, 2011	19:34	30.0	2.02	19.432	122.216
May 4, 2011	19:35	30.0	2.02	19.432	122.216

The range of data in Table 5 cannot be clearly appreciated in the graph of this FIG. 20 because the amount of data plotted is over 5,500 records, and Table 5 only shows 16 records. The exact point of the data in Table 5 in the level graph is shown in FIG. 20 with reference number 104.

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.