SPECIFICATION

Field of the In vention

The present invention relates to a separator unit for separating oil and water produced from oil wells.

Background of the Invention

In addition to oil, oil wells typically produce Unwanted fluids such as water. As fluid is produced to the surface by the well, it is desirable to separate water from the oil at the well site, before the oil is transported or sold,

In the prior art:, separator units and storage tanks are brought to the well site. This involves loading the separator unit onto a truck and trucking the unit to the well site. Likewise, storage tanks are loaded onto one or more additional trucks and the tallies are trucked to the well site, The separator unit and storage tanks are typically oversized. As a result, when trucked to the well site., special procedures are followed, such as using escorts warn, motorist of the wide load; All of these trucks and special procedures add to the cost of trail sporting; the equipment to and from the wel! site.

Once delivered to the well site, the separator ^■ unit Is located relative to the well and the storage tanks are located relative to the well and the separator unit Lines runnin from the well to the- separator unit are lumfaedL as are lines from the -separator unit to the storage tanks. ^" Hie setup and installation of the equipment is time consuming and laborious. Once installed, the well is produced into the separator unit and the wate Is stored in a storage tank. The oil is stored in a separate storage tank,.

Thus, it is expensive to provide a well site with a separator and separate storage tanks for oil and water. Included in the cost is not just the equipment, but the cost of installation and removal of the equipment. In some wells, the cost, of such equipment may be too expensive relative to the production of the wells. For example, in small stripper wells, small quantities of oil are produced. Such wells may produce large amounts of water relative to oil and thus be in need of a separator and storage. Yet, the cost of installing and. removing the equipment may be prohibitively high.

There is a need for a less expensive, less labor intensive,- and more ecological reflective designed portable test separator unit.

Summary of the Invention

A towable separator unit for oil wells, comprise a chassis, wheels rotatable mounted to the chassis so the chassis can be towed and a walled enclosure supported b the chassis. The enclosure ha top, bottom, exterior side and end wails, the walled enclosure having interior sid walls arranged so as to form, a first tank, a second tank: and a third tank, each of the first, second, and third tanks capable of holding a fluid without leaking. An inlet pipe is structured and arranged to connect to an oil well, the inlet pipe communicating with the first tank so as to deliver fluids from the oil well into the first tank. A first transfer pip has an inlet located in a bottom region of the first taftk, The first transfer pipe having an outlet located in one of the second or third tanks, the first transfer pipe located interiorly of the walled enclosure, A second transfer pipe has an inlet located in a top region of the first tank, the second transfer pipe having an outlet located in the other of the second or third tanks, the second transfer pipe sloped downwardly from its inlet to its outlet, Each of the second and third tanks having an outlet.

I accordance with one aspect, the first, second and third tanks are arranged longitudinally inside the waile enclosure, with the second tank between the first and third tanks.

in accordance with another aspect the top wall of the walled enclosure has a step down portion that is stepped down from the first tank to the third tank, the second transfer pipe is located exterior to the stepped down portion of the top wall, fisriher comprisin a valve i H e exteri r portion of the second transfer pipe.

In accordance with another aspect, the inlet pipe is connected to a flume located in the first tank, the flume extending vertically from the top wall toward the bottom wall, the flume having a lower portion with openings therein to allow th well fluid to enter the first tank, further comprising a perforated coa!escer above -the. flume openings.

In accordance wit anothe aspect, the first transfer pipe comprises a water leg.

In accordance w th another aspect, the third tank has plural outlets arranged vertically along the third tank, In accordance with another aspect, farther comprising a level se sor in at least one of the first, second or third tanks, the level seiisor providing liquid level information to a display o the exterior of the walled enclosure.

In accordance with another aspect, farther comprising a wireless transmitter connected to the level sensor to provide level information remotely from the well.

In accordances with another as ect the level senso measures the level of oil and also measures the level of water in the respective tank .

In accordance with anotlief aspect, wherein the inlet of the second transfer pipe comprises a stub removably connected to the second transfer pipe and having a length so as position the inlet of the second transfer pipe at a predetermined location above the bottom wall of the first tank,

I accordance with another aspect, the unit is road legal.

Bri ef Description of the Dra wings

Fig. 1 shows the separator writ at a well site, connected to -a well.

Fig, 2 is a side view of the separator unit, in accordance with a preferred eiiibodiro:ent.

Fig, 3 is a top view: of the separator unit

Fig. 4 is a rear end view of the separato unit.

Fig. 5 is a front end view of the separator unit

Fig. 6 i s a partial cross-sectional side view of the separator unit.

Fig, 7 is a side elevational view of the fliinie.

Fig, 8 is a side elevational view of the water leg. Fig, 9 is a detailed side .elevatioaal. view of the inlet to the oil transfer pipe.

Fig, 10 is a schematic view of a level sensor.

Fig. 1 1 is a block diagram of the sensor system.

Fig, 12 shows a liquid level sensor in accordance with another embodiment.

Description of the Preferred Embodiment

Fig. 1 shows an oil well site wit an oil well 1 1, The oil well is a stripper well that produces a small quantity of fluid on a daily basis. Much of the fluid produced is oil, but a quantity of water is also produced. In order to separat the oil and the water and store both types of separated fluids _. , a separator unit 15 is used,

The separator unit 15 is portable and fully self-contained. It is suitable for being towed on roads and simpl to install and make ready for operation. Once m operation, the separator unit 15 is reliable with no active components such as pumps. Much of the plumbing is internal where it is protected from freezing and being damaged when the unit is towed on the road. Because little work needs t be done to set up and remove the separator uni 15 from a well site, the unit is- safer to install and remove and is also sate to operate.

When no longer needed, the separator unit 15 can easily be disconnected and towed off of the well site and reused at atiother well site. The separator unit 1.5 (see Fig. 2) is a self-contained trailer, having a chassis frame 1,7, wheels 19 and a towing hitch 2.1. The trailer has a front end 23 near the hitch, and a rear end 25 near the wheels 1 .

In addition, the separator uni has three tanks or cottipartoents, namely an oil-water tank 27 (see Fig. 6), a water tank 2 and a oil tank 3 L Each tank has a floor 33, a top 35 and exterior side walls 37, The exterior side walls 37 are eoiTugated Each tank is provided wit an access hatch 38 i the respective side wall. There are also interior side walls 39, 4.1 between the tanks. The oil-water tank 27 shares a sid wall 3 with the water tank 29. The water tank 29 shares a side wall 41 with the oil tank 31 , The interior surfaces of the tanks are epoxy coated,

I the preferred embodiment, th oil-water tank 27 Is located at the rear end 25, the oil tank 31 at the front end 23 and the water tank _. 2 between the other two tanks. The oil-water -tank and oil tank are shout the same volume, while the water tank is smaller in volume, in the preferred embodiment. The relative sizes of the tanks can he changed to suit the particular needs of the well site. B wa of example only , the oil- wate tank can be 210 barrels, the oil tank 214 barrels and the water tank ISO barrels;

The to 35 of the unit is stepped dow from the rear end 25 to the front end 23. The top of the oil water tank 27 is highe than the tops of the other two tanks 29, 1... The top of the water tank 29 is stepped down 79 at a location between the interior side walls 39, 41 (see Fig. 6), Steps 43 or a ladder can be provided at the front end 23 (see Figs. 2 and 5) to allow personnel to access the top 35. The rear end 25 is equipped with lights 45 so that the trailer ca legally travel on roads (Fig. 4), An inlet pipe 47 is connected- to th oil-water tank 27. The inlet pipe 47 is connected to the well 11, _. either directly, or indirectly by way of equipment such as a. gas separator. The inlet pipe 47 extends along the exterior of the rear end 25 and along the top 35 of the oil-water tank 27 to a vertical pipe or flume 49, .Referring to Fig, 7, the flume 49 has an exterior, or upper, portion 51 and an interior, or lower, portion 53. The interior portion S3 is a pipe that extends - from the top 35 to the floor 33 of the oil- water tank 27, The top end of the pipe extends above the tank to 35 for a short distance, The pipe has cutouts or openings 54 in its lower end to allow the liquid in the pipe to escape into the tank 27. A spreader 55 _> or co escer _> is provided a distance above the floor 33, The spreader is located above the openings 54, The spreader 55 is attached to and extends out horizontally from the pipe. The spreader 55 is a perforated pkie or mesh arid could be made of expanded metah The spreader can be a flat plate. If so, then the plate is provided with a downwardly depending skirt 56 that extends around the circumference of th plate. Alternatively, the plate can be domed, with the outer edges lower than the center, Thus, the oil and water is retained under the spreade For a period of time to allow the oil to coalesce. The lower portion o the flume 49 is located in the cente of the lowest part of the tank 27

The upper portion, 51. stands up from the top 35 of the tank. The upper portion 51 is hinged 57 or otherwise movabl coupled to the lowe portion 53 top end. When the separator unit 15 is being transported, the upper portion 51 is laid down as shown- by dashed lines in Fig, 7 in order to reduce the overall height of the unit. As an alternative _. , the upper portion 51 can foe completel removed and stowed in a bracket o the side of the unti m order to lower the overall height of the unit. Handles can be provided o the upper portion to assist in moving the portion into place. On installation, th upper portion 51 is raised to a vertical position and is secured to the lower portion S3 with one or more clamps. A gasket between the upper and lower portions provides a seal. The e iinection is preferably a quick release e!amp with single bolt This is in contrast to a typically pip flanged connection with a number of bolts. The quick release clamp saves time in setu and take-down. The inlet pipe 47 is connected t the upper portion 51 , The inlet pipe 47 has a flexible portion 4 A that extends from the top wall to the flume top 51 to accommodate the flume top 51 movin about the hinge.

Water is transferred from the oil-water tank 27 to the water tank 29 by way of a water leg 59 (see Fig. 8), The water leg 59 has an upside down "U" shape and is located in the oil-water tank 27, Thus, there are two vertical pipes 61 joined together by a horizontal pipe 63 which is located some distance above the floor 33. One end of one of the verticai pipes 61 is open 65 to the oil-water tank 27 and is located close to the floor 33. The other vertical pipe 61 joins to a horizontal pipe 67 which passes through, the side wail 3 into the water tank 29 where it is open. A vertical riser 69 extends from one of the vertical pipes 61 above the top 35, A weather cover can be provided over the open riser 69.

Oil is transferred ^' from the oil-water tank 27 to the oil tank 31 by an. oil transfer pipe 71. The inlet 73 to the pipe 71 is located near the to 35 of the oil tank 27 (see Fig. 9), Th height of the inlet 73 above the floo 33 can b adjuste by adding or subtracting the lengths of vertical pipe stubs 75. For example, adding a pipe stab 75 on top of the pipe creates ah inlet 73 A that is higher relative to the floor 33 , The stubs 75 can be threaded into the pipe 71 , A access hatch 77 is provided on the top 35 in order to access the inlet 73 (see Fig, 3).

The oil transfer pipe 1 exits throug the side wall 39, extends along the upper portion, of the water tank 29 for a di stance and exits the water tank at the step down partition 79. The pipe 71 continues along the to exterior toward the front end 33 where it enters the oil tank 31 at the top, The pipe is sloped down from the oil- water tank to the oil tank, A valve 81 is provi ded _^ which valve is accessed from the top 35 of the unit.

An overflow and skim oil pipe 83 is provided between the water tank 29 and the oil tank 31 , The overflow pipe 83 (see Figs. 3 and 6) has an inlet near the to of the water tank 29 and extends out of the wate tank at th step down 79, The pipe 83 then enters the top of the oil tank 31. The pipe 83 is provided a valve 85, accessible from the top. Personnel can use the stairs 43 to climb on to and access the valves 81, 85 as well as access hatches.

On : or more tanks 27, 29, 1 are provided with level sensors 87 (see Fig, 10), The sensors are conventional and commercially available. A tube 89 extends vertically inside the respective tank ^■ through the top down to the bottom or floor, toroid float 91 can travel along the tube and tracks the liquid level 92. As the float 91 moves. Its position is detected by magnetic sensors inside the tube. In addition, the temperature of the fluid can be sensed by the unit. Electronic package 93 is located on top of the tube and sends the level and temperature information to a display 95 (Fig, 11), which is mounted at the front end 23 (Fig. 5). Referring to F g. .11 , the level sensors 87 report to a monitor 97 which electronically monitors the levels. If a level in a tank exceeds a predetermined level, the monitor 97 initiates an alarm. The alarm is provided on the display and is also sent offsite by a wireless communications link,: such as a satellite link (or cellular telephone link). A receiver 99 located offsite receives the alarm. The receiver can be a cellular telephone or smartphone. The system allows offsite personnel to monitor the status of the unit 15 to minimize overflow from the tanks . In addition to sending alarm information, the system ca also send status updates on the liquid levels and temperatures. These can be sent o a periodic basis. The system can include a GPS (global positioning system) unit 100, For example, the monitor and transmitter 97 can include a GPS unit 100, wherein the location of the separator unit 15 is transmitted to the receiver 99, The GPS unit 100 allows the separator unit 15 to be leased on. a per location basis. If the unit Is moved to another location outside of the terms of the lease (and without permission of the owner)? the owner will know that the lease has been violated.

Fig, 12 illustrates another embodiment of a liquid level sensor 109. A vertical tube 111 is provided from the top wall 35 to the bottom 33. The tube has a iongitundinal slot therein to allow liquid in the tank to enter the tube at various levels. Alternatively,. -the tube can be provided with a series of slots or openings along the length of the tube to admit liquid therein, Inside th tube are two floats that move along the length of the tube interior _* One float 113 is on top of the oil 115, while the othe float 117 is on to of the water 119, Also inside of the tub 111 are magnetic sensors 121 that sense the positions of the two floats 1 1,3, 117. The magnetic sensors are connected to the electronic package 93.

The sensor 109 is used in a tank having both oil and water. For example, one sensor 109 can be used in the oil-water tank 27 while another sensor 109 is used in the oil tank 3-L The water tank 2 ca be provided with the sensor 109, however typically the water tank contains little or no oil.

As the levels of liquid 115, 119 vary, the respective floats 113, 117 move along inside the tube, with the oil float 1 13 following the oil level 115 and the water float 117 following the water level 1 19, The positions of the floats are sensed by the sensors 121, which are read by the electronics package 93 and sent to the display 95 and the receiver 99.

The water and oil tanks 29, 31 have takeoff valves in the respective side walls 37, The water tank 29 takeoff valve 101 (see Fig. 6) is located near the floor or bottom of the tank. The valve 101 allows a hose t be connected thereto so that water m the tank can be loaded into, a truck for transport offsite.

The oil tank 31 lias a number of takeoff valves 103 (see Fig. 5) vertically staggered and located at the front end 23. Thus, the valves allow user to sample the liquid inside at: various vertical position or vertical levels inside the tank. The oil Inside the oil tank 31 is typically marketable, However, there ma be some water located at the bottom. Mien art operato arrives to offload oil, the operator can ope the various- valves 103 to determine where the bottom level of the marketable oil is. For example, the operator can open the bottom valve. If wate comes out or a combination of Water and oil comes out,, the operator knows that there is water at that

1.1 particular level. The operator can open the next highest valve. If oil comes out of the valve, then the operator knows that oil is located at that level and above. Therefore, th operator would connect the hose to that valve, open a valve to offload the liquid oil for transport offsite.

In operation, the unit 15 is towed to a well site. The unit is road legal, with lights and with a width and a height that allows It to be taken on public roads and beneat bridges and overpasses. An escort fo the towed vehicle need not be provided as the unit 15 is towed on public roads. This saves labor and expense. At th well site, the unit is positioned as desired, The unit is the lowered to the pound; the chassis 17 bears on the ground. The well is connected to the inlet pipe 47, The exterior portion 51 of the flume 49 is raised, to a vertical position and clamped in place, 111 addition, hand rails 105 can b installed on the landing, which hand rails have been taken off and stowed for transport. As an alternative, the stairway, landing can be lowered so as to lower th overall height of th hand rails 105, whic hand rails can the be permanently attached. Hand rails can be permanently attached along the steps up to the landing, The truck towing the trailer is. disconnected and can be used for other jobs, Gnee connected, the unit is ready for operatio and the well can be opened to produce into the unit. Oil and water flow tlirough the inlet pipe 47 and descend into the oil-water tank 27 via th flume 49. The liquid exits the flume through th openings 54 in the bottom. The water naturally stays at th bottom while the oil rises to th top, The spreade 55 slows the ascent of the oil and serves to eoalesce small globules of oil into larger globules, which makes separation more effective. The flume 4 thus slows the velocity of the incoming liquid, in order to assist in separation.

The overall fluid level in the oil-water tank 27 rises as liquid continues to enter. When the level is. high enough, water passes from the bottom of the oil- water tank 27, through the water leg 5 and into the wate tank 29. Likewise, oil enters the oil transfer pipe 71 near the top of the oil tank 27 and flows into th oil tank 31. Thus, separation is. accomplished automatically.

Overflow protection and skim oil capability is provided For example, in the preferred embodiment, the water tank 2 is smaller In volume than the oil tank 31. If an operator, when onsite,. and reading the display 95, notices th water level in the water tank is hig and close to overflowing, the operator can ope the valve 85 and allow water to exit the water tank 29 via the overflow pipe 83 into the oil tank 31. The operator is thus able to prevent a spill, which spill could hav environmental consequences. Alternatively, if the wate tank were larger than the oil tank, an overflow pipe could be provided which allows flow from the oil tank into the water tank.

Although Liquid level sensors can be provided in one or more of the tanks 27, 29, 31, sight glasses could be used as an alternative _* Such sight glasses however are subject to: breakage and, If filled with water, freezing.

The overflow pipe 83 can be used to transfer skim oil out of the water tank 29. The skim oil is at the to level of liquid in the water tank. An perator can. open the valve 85 to transfer the skim oil out of the water tank 29 into the oil tank 31. The separator unit is easy to install and set up, easy to remove from a well site and low in maintenance. It operates automatically, needing only occasional visits to offload the water and the oil, typically by truck. It is desired for cold, climate use, as the water lines are all ulterior and not subject to freezing.

The separator unit can be operated and liquid levels monitored by personnel on the ground. Personnel need not climb on top to gauge liquid levels, but can read the levels on the display 95. The offload valves 101, 103 are provided at ground level.

To remove the separator unit 15 from the well site, the well is disconnected by disconnecting the line 47. Preferably, the tanks 27, 29, 31 are emptied into other vessels to reduce the weight of the unit 15, Ail protruding objects such as the flume top and handrails are stowed. A towing vehicle is backed to the unit and connected to the trailer hitch 21. As the unit f ont end is lifted ont the towing vehicle, the chassis 17 is lifted off the ground and the wheels 1 bear the weight. The unit 15 can now be_towed on the wheels 19. Thus, the unit is both set up and removed simply and quickly, saving on labor and materials.

The unit 15 is road legal and is not an oversized load. As a result, one or more escorts for transporting the unit along a public road are not required. An example of a road legal load is a width not exceeding 102 inches and a height not exceeding 13 fee .6 inches, The unit 15 is within these dimensions.

Although, the unit 15 can be used as a seli^contamed separator, i some situations,, the unit can be used in conjunction with other equipment. For example, the unit can be used with a separate water tank, if the well produces too muc water for the wa er tank 29 and additional -water storage is needed. As another example, the unit 15 can be used with a separate oil tank, to provide additional oil storage on the well site _*

The foregoing disclosure and showings made i the drawings are merely iilustrative of the principles of this invention and are not to be interpreted i a limiting sense.