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

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.

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.