US2905135A

US2905135A - Warning device for oil wells

Info

Publication number: US2905135A
Application number: US536149A
Authority: US
Inventors: Harry R Jukes
Original assignee: Gulf Research and Development Co
Current assignee: Gulf Research and Development Co
Priority date: 1955-09-23
Filing date: 1955-09-23
Publication date: 1959-09-22
Anticipated expiration: 1976-09-22

Description

Sept, 22, 1959 H. R. JuKEs WARNING DEVICE FOR OIL WELLS Filed Sept. 25. 1955 IN V EN TOR.

l/A/QQY Q. JUKES HAS A T TORNEY United States Patent *Ofiice Patented Sept. 22, 1959 WARNING DEVICE FOR OIL WELLS Harry R. Jukes, Cut Off, La., assignor to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware Application September 23, 1955', Serial No. 536,149

6 Claims. (Cl. 116-50) This invention relates to a warning device for oil wells, and more particularly to a device which automatically comes into operation when the pressure at a well head falls below a preselected degree and by means of which the well fluids are utilized to actuate an alarm and so call attention to the changing condition.

In the production of petroleum oil from wells, the pressure under which the oil flows into the well from the surrounding formation varies over a wide range. The oil may barely trickle into the well or it may enter under a pressure measured in thousands of pounds per square inch. The oil so produced may or may not be accompanied by salt water and gas or either of these two. This invention relates to the production of oil from wells in which the well fluids are under a suflicient pressure at the bottom of the well to carry the entire production to the well head and beyond so long as the various well fluids, oil, water, and gas, are in their initial proportions, but in which the pressure at the bottom of the well is less than the hydrostatic head of a well full of water.

In producing oil under present day limitations on the quantity produced, it is ordinarily necessary to restrict the output of each well by means of mechanical devices known as chokes. This restriction upon the output sometimes reduces the velocity of the stream rising in the well tubing to a point at which the salt water accompanying the oil partially separates out in the tubing and, if'not attended to, gradually builds up a column of salt water in the tubing which has a hydrostatic head equal to the formation pressure of the well fluids at the bottom of the hole. Sometimes the formation pressure is so slightly in excess of the hydrostatic head of the column of well fluids that a relatively minor degree of separation and consequent increase in the proportion of water in the tubing will overcome the formation pressure. When the hydrostatic head of the column of fluid in the tubing equals the formation pressure at the bottom of the well it of course shuts off all flow from the well and the well is said to die.

When a well is dying, the falling off of pressure at the well head continues over a period of hours and the condition can be corrected at this stage by temporarily increasing the rate at which the well is permitted to flow. This increased flow rate is maintained until the accumulated water in the well has been carried out and replaced by a column of the various well fluids in their normal proportion, whereupon the well is shut in again to its allowed producing rate.

Should the well die completely before it receives attention, it is then necessary to reestablish production by the use of gas under pressure or by swabbing, either of which are expensive operations. For this reason it becomes desirable to fit wells that are flowing under moderate pressure with some sort of a device to bring any such a falling pressure to the attention of an attendant. Except for the need of prompt attention when a well is losing head and in danger of dying, it is possible to assign one pumper to a very large number of wells, spread over a large area, in which case the pumper may not have opportunity to attend each individual well more often than once a day. To permit this efllcient use of scarce labor it is necessary to have some automatic device such as the signal device of my invention. This device will summon the pumper in emergencies to the place where his services are most immediately required.-

The signal device of my invention is shown in the accompanying drawings, which consist of Figures 1 and 2.

In the accompanying drawings Figure 1 shows a schematic arrangement of the invention, and Figure 2 is a sectional view of diaphragm-controlled valve 8.

Referring to Figure 1, numeral 1 indicates the tubing at the top of the well. Numeral 2 indicates a multipleoutlet head, commonly known as a manifold, positioned at the top of tubing 1 and constituting the upper terminal thereof, this head being fitted with valves and choke for controlling the discharge of well fluids therefrom. This device is sometimes referred to as a well head device. Control handles 20 are indicated on the manifold. The produced oil leaves manifold 2 through flow line 3, which latter is fitted with pressure indicating gauge 4. A conduit 5, fitted with pressure indicating gauge 19, leads from manifold 2 to the high pressure side of a conventional pressure-reducing valve 13. Conduit 6 leads from the low pressure side of pressure-reducing valve 13 to the base '7 of the diaphragm-controlled valve device, or structure, indicated over-all by numeral 8. The construction of diaphragm-controlled valve device 8 is shown in detail in Figure 2. The well fluids from line 6 do not pass through diaphragm-controlled valve device 8 but merely exert their inherent pressure on the diaphragm thereof and indirectly control passage of other fluid through the upper or controlled part 24 of valve device 8 as will subsequently be described. A gas cylinder 15 containing an expansible gas under high pressure is in communication through conduit 9' with the upper (controlled) section 24 of diaphragm-controlled valve device 8 and discharges therefrom through outlet 11 to whistle 12 or other pneumatically operated signaling device when the upper section 24 of diaphragm-controlled valve device 8 opens. These elements together constitute one continuous conduit, channel, or connecting passageway from gas container 15 to the pneumatically operated signaling device 12; A pressure gauge 14 is provided to indicate the pressure of the gas in cylinder 15. 4

Referring to Figure 2, this is a sectional view of dia phragm-controlled valve device 8, previously mentioned in connection with Figure 1. Valve device 8 comprises a lower body casing 21, an upper body casing 22, and cap 23. Upper body casing 22 is separated into an upper chamber 24 and a lower chamber 25 by means of partition 26. A flexible diaphragm 27 is held between lower body casing 21 and upper body casing 22, and these elements are fastened together by screws, bolts, or equivalent means 28. A valve stem 30, carrying valve closure element 29 on its upper extremity passes through partition 26 and the passageway is closed against leakage of fluid by packing held in place by gland 3 1. The lower end of valve stem 30 is fastened to a cup 32 positioned on the upper surface of flexible diaphragm 27. Surrounding valve stem 30 and extending upward from cup 32 to the underside of partition 26 is a coiled spring 33. An upstanding flange on cup 32 holds the spring in place at its lower extremity, and annular flange 34 maintains it in position at its upper extremity. Spring 33 is maintained under such a degree of compression as will permit flexible diaphragm 27 to force closure element 29 tight against its seat, thereby closing the valve, when the pressure on the underside of diaphragm 27 is in excess of some preselected degree, e.g. 250 pounds per square inch above atmospheric, and which will open the valve when the pressure on the underside of diaphragm 27 falls substantially below the preselected pressure.

Pressure reducing valves designed to receive a fluid under a high pressure and to discharge it under a uniform lower pressure, such as valve 13, are very common and simple mechanical devices and require no detailed description here.

The operation of my device is as follows:

Well fluids issuing from the well through tubing 1 are discharged therefrom through control means 2 such as the well-known Gray composite manifold shown in Figure 1. Before discharging from manifold 2 into flow line 3 the well fluids are passed through a choke, built integral with the manifold, to restrict the flow of oil from the well. In the apparatus of my invention, well fluid from tubing 1 flows through manifold 2 and conduit 5 to the high pressure side of conventional pressure-reducing valve 13. After having its pressure reduced by pressure-reducing valve 13, the well fluid flows from the low pressure side of that valve through conduit 6 to the base 7 of diaphragm-controlled valve device 8. The pressure of the well fluid from conduit 6 operates on the underside of diaphragm 27 of valve device 8, and when the pressure of that fluid is in excess of some preselected value, eg 250 pounds per square inch, the diaphragm is forced upward and the closure element 29 is forced against its seat in the upper section 24 of valve device 8. When the pressure in tubing 1 and conduit 6 falls below the aforementioned preselected pressure, closure element 29 is pulled away from its seat by spring 33, thereby opening the valve. The opening of the valve permits compressed gas from cylinder 15 to flow through conduit 9, enter valve device 8 through inlet connection 10 into the upper section 24 thereof and to pass out of valve device 8 through outlet connection 11 to a whistle 12 or to some other pneumatically operated signaling device. The pneumatically energized signaling device may be operated with the aid of a piston or a fluid operated motor or any equivalent means. Pressure-reducing valve 13 may be of any conventional type and is provided to protect the diaphragm of valve device 8 from any excessive pressure existing in tubing 1. A pressure of 250 pounds per square inch is a safe and effective pressure for energizing diaphragm-controlled valve device 8, and pressure-reducing valve 13 can advantageously be set to maintain this pressure.

In a specific embodiment of my invention the apparatus is constructed precisely as shown in Figures 1 and 2, including a whistle 12. The pressure at the well head, as indicated by gauge 19 was 525 pounds per square inch. The pressure-reducing valve 13 was set to reduce the pressure of the well fluids from 525 pounds to 250 pounds per square inch. The pressure of the expansible gas in gas cylinder was 1500 pounds per square inch.

Of course, if the pressure in conduit 9 is not too high for the safe operation of diaphragm valve device 8 it is altogether satisfactory to omit pressure-reducing valve 13 from the apparatus.

I claim:

1. In combination with an oil well, a signal device which comprises a well tubing adapted to convey well fluids from the well; a gas chamber adapted to hold an expansible gas under superatmospheric pressure; a sonic signaling device; a conduit extending from the said gas chamber to the said signaling device; a valve device interposed in the said conduit, and, as a part thereof, a closure element operating to open and close the said conduit in response to changes of fluid pressure of the well acting upon a pressure-sensitive flexible diaphragm element of the said valve device opening the said conduit when the said fluid pressure falls below a preselected degree and closing the said conduit when the said fluid pressure exceeds a preselected degree; and a second conduit providing communication from the well tubing to the said pressuresensitive flexible diaphragm element of the said valve device.

2. In combination with an oil well, a signal device which comprises a well tubing adapted to convey well fluids from the well; a gas chamber adapted to hold an expansible gas under superatmospheric pressure; a pneumatically operated signaling device; a conduit extending from the said gas chamber to the said signalling device; a valve device interposed in the said conduit and, as a part thereof, a closure element operating to open and close the said conduit in response to changes of fluid pressure of the well acting upon a pressure-sensitive flexible diaphragm element of the said valve device opening the said conduit when the said fluid pressure falls below a preselected degree and closing the said conduit when the said fluid pressure exceeds a preselected degree; and a second conduit providing communication from the well tubing to the said pressure-sensitive flexible diaphragm element of the said valve device.

3. In combination with an oil well, a signal device which comprises a well tubing adapted to convey well fluids from the well; a gas chamber adapted to hold an expansible gas under superatmospheric pressure; a pneumatically activated signaling device; a conduit extending from the said gas chamber to the said signalling device; a valve device interposed in the said conduit and, as a part thereof, a closure element operating to open and close the said conduit in response to changes of fluid pressure of the well acting upon a pressure-sensitive flexible diaphragm element of the said valve device opening the said conduit when the said fluid pressure falls below a preselected degree and closing the said conduit when the said fluid pressure exceeds a preselected degree; and a second conduit providing communication from the well tubing to the said pressure-sensitive flexible diaphragm element of the said valve device.

4. In combination with an oil well, a signal device which comprises a well tubing adapted to convey well fluids from the well; a gas chamber adapted to hold an expansible gas under superatmospheric pressure; a sonic signaling device; a conduit extending from the said gas chamber to the said signaling device; a valve device interposed in the said conduit, and, as a part thereof, a closure element operating to open and close the said conduit in response to changes of fluid pressure of the well acting upon a pressure-sensitive flexible diaphragm element of the said valve device opening the said conduit when the said fluid pressure falls below a preselected degree and closing the said conduit when the said fluid pressure exceeds a preselected degree; a second conduit providing communication from the well tubing to the said pressuresensitive flexible diaphragm element of the said valve device; and a pressure reducing valve interposed in said second conduit.

5. In combination with an oil well, a signal device which comprises a well tubing adapted to convey well fluids from the well; a gas chamber adapted to hold an expansible gas under superatmospheric pressure; a pneumatically activated signaling device; a conduit extending from the said gas chamber to the said signaling device; a valve device interposed in the said conduit and, as a part thereof, a closure element operating to open and close the said conduit in response to changes of fluid pressure of the well acting upon a pressure-sensitive flexible diaphragm element of the said valve device opening the said conduit when the said fluid pressure falls below a preselected degree and closing the said conduit when the said fluid pressure exceeds a preselected degree; a second conduit providing communication from the well tubing to the said pressure-sensitive flexible diaphragm element of the said valve device; and a second valve interposed in said second conduit to reduce the pressure of the fluid passing therethrough from well tubing pressure to a pressure intermediate the well tubing pressure and the pressure necessary to close the firstmentioned valve.

6. In combination with an oil well comprising a well tubing to conduct well fluids from lower portions of the well, and a multiple outlet well head device positioned at the top of the well tubing and constituting the upper terminal thereof, a flow line extending from one outlet of the said well head device to conduct well fluids therefrom; a gas chamber adapted to hold an expansible gas under superatmospheric pressure; a pressure actuated' valve device having a conduit therethrough, an inlet connection to the conduit, an outlet connection from the conduit, a closure element in the said conduit, a pressure chamber with pressure-responsive flexible diaphragm therein, and an inlet connection to said pressure chamber, the said pressure-responsive flexible diaphragm being operatively connected to the said closure element to close the said conduit when the pressure-responsive flexible diaphragm is subjected to a predetermined pressure and to open the said conduit when subjected to less than that pressure; a conduit in open communication with the said gas chamber and extending therefrom to the inlet connection of the valve device conduit; a sonic signaling device in open communication with the outlet connection of the said valve device conduit; and a second conduit, this extending from a second outlet of the said well head device to the inlet connection of the pressure chamber of the valve device to convey well fluid thereto for action on the pressureresponsive flexible diaphragm therein.

References Cited in the file of this patent UNITED STATES PATENTS