Hydrocarbon production system and method of use

Abstract

The method of the present invention provides a means to intake hydrocarbon fluid from a subsurface hydrocarbon reservoir, including any accompanying ground water or earthen contaminants, into the subsurface lower end of a tubing system. Compressed gas is then used to purge the hydrocarbon fluid and earthen contaminants from within the tubing system to a hydrocarbon production fluid storage tank or other handling facility at surface.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The purpose of the method of the present invention is to provide an improved method and an improved apparatus to displace light, medium, heavy or viscose hydrocarbon fluid that may contain earthen contaminants from subterranean hydrocarbon reservoirs, to a hydrocarbon production fluid storage tank or other handling facilities on ground surface, by means of oil well production, wherein all currently used subsurface production pump systems are mechanically incapable of sustained or economic production.

The method of the present invention provides a means to intake hydrocarbon fluid from a subsurface hydrocarbon reservoir, including any accompanying ground water or earthen contaminants, into the subsurface lower end of a tubing system. Compressed gas is then used to purge the hydrocarbon fluid and contaminants from within the tubing system to a hydrocarbon production fluid storage tank or other handling facility at surface. Other than hydrocarbon fluid and compressed air or gas movement, the ball of a subsurface intake valve is the production system's only moving subsurface component. A titanium subsurface intake valve is commonly available and has a much extended service life even when displacing hydrocarbons containing very high volumes of earthen materials including pyrite balls, rock and coal fragments, ground water, fine or course water sand or oil sand. The method is also useful in displacing hydrocarbon fluid to surface from well-bores that deviate off the vertical due to drilling problems or intentional deviations caused in drilling slant, whipstocked or horizontal oil wells.

2. Description of Prior Art

Within some oil wells, subterranean hydrocarbon reservoir characteristics, hydrocarbon fluid characteristics, drilling problems or the well-bore design may present problems wherein continuous or more economical hydrocarbon production is difficult or not possible while employing current production systems including subsurface sucker rod driven plunger pumps, progressive cavity pumps or other types of subsurface production pumps.

Sucker rod activated tubing liner or insert type subsurface production pumps are the mainstay of most oil fields around the world, and are very well suited to the production of light and medium hydrocarbons and will often operate trouble free for numerous years. When used for the production of more viscose hydrocarbons, heavy oil or bitumen, the sucker rods will often float on the downstroke and must be slowed down to prevent pump jack and sucker rod damage. If the hydrocarbon fluid contains considerable amounts of earthen particulates, the earthen particulates may accumulate and cause blockages within the subsurface production tubing and surface flow line. When the accumulation of earthen particulates becomes too great, the sucker rods simply will not fall at an acceptable fall rate, through the column of hydrocarbon and earthen materials. Production thereby fails, and well servicing is required. The earthen particulates may also cause extreme abrasion of the sucker rods and production tubing and premature failure of each, which requires replacement of each. Sucker rod and production tubing abrasion, mechanical wear and stress is greatly increased in oil wells that have deviations off the vertical line due to drilling problems, or in slant, whipstocked or horizontal well-bores.

Progressing cavity subsurface production pumps driven by sucker rods are more successful in the production of the more viscose hydrocarbons and are, to a degree, somewhat better able to cope with the presence of earthen particulates. These pumps inherit all the problems associated with sucker rod use, are quickly destroyed when the well-bore fluid is pumped off or the rotors and stators are often badly damaged when pumping rock fragments or pyrite balls or sand slugs. They have a much shortened life when pumping considerable amounts of earthen particulates, especially water sand. Within many oilsands production wells, seizure of the sucker rods by accumulations of earthen particulates packed within the subsurface production tubing string is a never ending problem that may occur daily. The rubber stator component of the progressing cavity subsurface production pump is easily damaged by sand slugs, rock or coal fragments, pebbles, pyrite balls or the high pumping pressure encountered when accumulations of earthen particulates begin to block the flow of hydrocarbon production within the subsurface production tubing or surface flow line.

A great number of oil wells producing heavy oil or bitumen from earthen particulate laden subterranean hydrocarbon reservoirs would be rendered technically or economically inoperable without the very expensive and frequent backup services of auxiliary equipment including pressure trucks, flush-by rigs, well servicing rigs or coiled tubing rigs to remove accumulated earthen particle build-up and/or blockages from the oil well's well-bore, subsurface production pump, subsurface production tubing, and surface flow line. Frequent replacement of subsurface components due to excessive metal to metal wear and/or metal wear due to the presence of abrasive produced earthen particulates within slant, horizontal, vertical or deviated well-bores presents considerable replacement cost in addition to the loss of sales revenue due to oil well down time.

Within a horizontal well-bore it would be advantageous to land a sucker rod activated subsurface production pump below the dog-leg. This is not usually practical due to the sharp production tubing curve, or dog-leg, wherein the sucker rods must rotate or reciprocate, causing excessive wear, fatigue and very rapid failure of sucker rods and/or subsurface production tubing. Horizontal oil wells having subsurface production pumps placed within or above the well-bore's dog-leg often have a problem with earthen particulates precipitating from the hydrocarbon fluid being drawn to the subsurface production pump and accumulating within the horizontal section of the well-bore and within the dog-legged section of the well-bore. Such precipitated accumulations continue to increase in volume until the flow of hydrocarbon fluid from the subterranean hydrocarbon reservoir is blocked from the intake of the subsurface production pump, and hydrocarbon production cannot be restarted until the earthen particulates are removed from the well-bore.

Commonly, very considerable amounts of earthen particulates precipitate from the hydrocarbon fluid after being drawn into the subsurface production pump and accumulate within the subsurface production tubing string and/or surface flow line. Eventually, precipitated earthen solids accumulations may cause production failure wherein production cannot be restarted until the earthen solids are removed from the subsurface production tubing. The problem of earthen solids precipitation within tubulars is greatly increased when greater water production volumes accompany the hydrocarbon fluid. New subsurface progressing cavity pump service life or operating time within such oil wells can often be as short as a day or two. If such oil wells do not clean up after spending substantial amounts of time, money, and fruitless effort, such oil wells are sooner or later considered to be mechanically or economically not viable, and are usually sold or abandoned.

SUMMARY OF THE INVENTION

More particularly, in accordance with one aspect of this invention, there is provided a compressed gas conveyance tubing system extending from a source of compressed gas at surface, down into and returning up out of an oil well having a subterranean hydrocarbon reservoir, oil well casing and casing perforations that provide hydrocarbon fluid inflow from the subsurface hydrocarbon reservoir into the well-bore, the improvement comprising a compressed gas conveyance tubing system including;

a source of compressed gas; a wellhead; conduit means to connect the source of compressed gas to the wellhead; a subsurface compressed gas feed tubing string extending from a connection at the wellhead to the approximate subsurface hydrocarbon reservoir depth of the well-bore; a subsurface production tubing string extending from the approximate subsurface hydrocarbon reservoir depth, through the wellhead to a surface flow line connection; a surface flow line with a connection at one end to the subsurface production tubing string, and a connection at the other end to a hydrocarbon production fluid storage tank or other fluid handling facility; a hydrocarbon production fluid storage tank or other fluid handling facility at ground surface; means to vent gas from the hydrocarbon production fluid storage tank or other fluid handling facility; a subsurface intake valve connected to the lower subsurface end of the compressed gas conveyance tubing system; means for fluid communication through the subsurface intake valve into the subsurface production tubing string and the subsurface compressed gas feed tubing string; means for fluid and gas communication through the subsurface compressed gas feed tubing string into the subsurface production tubing string; optional valve means to vent excessive gas pressure from the subsurface production tubing string; optional valve means to vent excessive gas pressure from the subsurface compressed gas feed tubing string;

In another aspect of the present invention, there is provided an improvement in a method of displacing various grades of hydrocarbon fluid from subterranean hydrocarbon reservoirs to surface storage by means of oil well production, which method includes the steps of;

Flooding hydrocarbon fluid from the subterranean hydrocarbon reservoir into the well-bore; means to evacuate or vent excessive gas pressure from within the subsurface section of the compressed gas conveyance tubing system; flooding hydrocarbon fluid from the well-bore through a subsurface intake valve and into the lower subsurface end of the compressed gas conveyance tubing system; closing the subsurface intake valve to contain the hydrocarbon fluid within the lower subsurface end of the compressed gas conveyance tubing system;

purging hydrocarbon fluid contained within the lower subsurface end of the compressed gas conveyance tubing system into a hydrocarbon production fluid storage tank or other fluid handling facility at ground surface by means of feeding compressed gas from a source at surface, through the compressed gas conveyance tubing system and into the hydrocarbon production fluid storage tank or other handling facility on ground surface; repeating the cycle; providing a means, when necessary, to separate hydrocarbon fluid and gas at ground surface; providing means to recover hydrocarbon fluid from the hydrocarbon production fluid storage tank or other handling facility at ground surface.

In the present system and method, in order to repetitively cycle the hydrocarbon production system through it's operating modes and cycles, employ optional operating modes, and apply the use of optional devices, it is recommended that a preferably programable or other suitable gas valve controller be employed to activate the production system's valves as required.

The subsurface compressed gas feed tubing string and the subsurface production tubing string are vented of excessive gas pressure when necessary, allowing well-bore fluid head pressure and/or optional vacuum created within the subsurface compressed gas conveyance tubing system by an optional vacuum pump at surface, to more easily and more quickly flood hydrocarbon fluid from the well-bore, into and through the subsurface intake valve and into the lower subsurface end of the compressed gas conveyance tubing system. The subsurface intake valve is then closed by gravity or other means, to trap the hydrocarbon fluid therein. The hydrocarbon fluid trapped within the subsurface compressed gas feed tubing string and subsurface production tubing string is purged, by means of compressed gas displacement, up the subsurface production tubing string, through the optional surface check valve, into and through the surface flow line, and into the hydrocarbon production fluid storage tank or other handling facilities at ground surface. Other optional modes and devices, as will be described later, may be incorporated into the present system.

As gas is compressed by the gas compressor in order to purge hydrocarbon fluid from the subsurface compressed gas conveyance tubing system to surface storage, much of the heat therein generated is carried by the compressed gas, into and through the subsurface compressed gas conveyance tubing system and may be used optionally to heat the hydrocarbon fluid contained therein, by means of close contact, conduction, or radiation between the heated subsurface compressed gas tubing string and the subsurface production tubing string. The heat transfer process may be readily understood by studying FIG. 2, and is very useful in making viscose hydrocarbon fluid less viscose, and subsequently reduces the required horsepower output of the gas compressor's prime mover and the gas compression required to purge the hydrocarbon fluid contained within the subsurface compressed gas conveyance tubing system to surface storage. The heat transfer method further serves to provide a saving in the amount of energy required to heat the hydrocarbon fluid within the surface hydrocarbon production fluid storage tank or other fluid handling facility.

In the present system and method, use is made of the fact that a compressed gas feed of sufficient volume and pressure can be employed to purge fluid volumes at considerable velocities through horizontal, vertical or inclined conduits. The increased fluid velocity additionally provides increased viscose hydrocarbon fluid shear properties and decreased fluid flow friction factors within the conduits. The fluid velocity, during the purge part of a normal production cycle, also provides a hydrocarbon fluid carrier stream to entrain and carry precipitated earthen particulate matter and rock fragments from the subterranean reservoir depth of the oil well, up the subsurface production tubing string, through the surface flow line and into a hydrocarbon production fluid storage tank or other handling facilities at surface.

It may be realized that the production apparatus of the present invention does not have sucker rods, or any moving subsurface components other than the ball of a subsurface intake valve, therefore extreme or mild sucker rod tensile stress and wear and abrasion between the none-existing sucker rods and the production tubing string is eliminated. Because there are no sucker rods, the method of the present invention is useful within oil wells that have any type of deviation from the vertical, such as well-bores that are vertical, vertical with drilling deviations, slant, whipstocked or horizontal. The method enables insertion of the subsurface lower end of the compressed gas conveyance tubing system into and through the dog-legged section of a horizontal well-bore in order to achieve hydrocarbon fluid extraction directly from the horizontal section of the well-bore. This advantage eliminates the precipitation and accumulation of earthen particulates that would otherwise accumulate and solidly plug the dog-legged section and entry section of the horizontal well-bore. By means of the compressed gas fed through the compressed gas conveyance tubing system during each production cycle, the bore of the subsurface production tubing string remains clear of all earthen particulate accumulations, rock fragments, pyrite balls and coal fragments as practically all hydrocarbon, earthen matter and water are purged through the subsurface production tubing and surface flow line, at a sufficient fluid velocity to entrain and carry earthen matter within the hydrocarbon fluid to surface storage. As the method does not employ a subsurface production pump, subsurface production pump wear and damage caused by pumping high fluid pressures due to blockages or considerable accumulations of earthen particulates, rock and coal fragments, pyrite balls, or high water cuts is eliminated.

In practice, the method of the present invention provides a hydrocarbon production method and apparatus that can displace hydrocarbon fluid from difficult oil wells without the problems of mild or extreme friction or premature subsurface component wear, earthen accumulations, particulate blockages or equipment flexibility limitations within deviated well-bores. Within oil wells that tend to pump dry frequently or unexpectedly, the method and apparatus of the present invention can operate impervious to equipment damage over any length of time without liquid inflow from the subterranean reservoir or other fluid source.

In carrying out the present invention, hydrocarbon fluid is fed from an oil well's subterranean hydrocarbon reservoir, by means of hydrocarbon reservoir pressure, through the casing perforations and into the lower well-bore. Hydrocarbon fluid from the well-bore is flooded into and through a subsurface intake valve, and into the lower subsurface end of the compressed gas conveyance tubing system by means of vacuum created within the subsurface section of the compressed gas conveyance tubing system, or forced through the subsurface intake valve into the lower end of the subsurface section of the compressed gas conveyance tubing system by means of the hydrocarbon fluid head pressure within the well-bore, or by a combination of vacuum and fluid head pressure, or by subterranean hydrocarbon reservoir pressure. The subsurface intake valve is then closed and the hydrocarbon fluid is trapped and contained within the lower subsurface section of the compressed gas conveyance tubing system.

A desired gas, or any practical gas of convenience such as natural gas, air, carbon dioxide or steam may be compressed and fed through the oil well's compressed gas conveyance tubing system, with sufficient volume and pressure as is required to purge the hydrocarbon fluid and it's earthen particulates and larger solids up through the subsurface production tubing string, through the wellhead, through a surface flow line and into a hydrocarbon fluid storage tank or other handling facility at surface. If desired, after the main volume of hydrocarbon fluid and it's contaminants are displaced to surface storage facilities, the compressed gas feed may be continued for a short time to entrain and carry residual produced hydrocarbon, earthen material and water from the compressed gas conveyance tubing system and surface flow line to the surface hydrocarbon production fluid storage tank or other handling facilities at surface.

Any number of optional modes or accessories may be added to the production system to provide solutions for problems within individual oil wells, including automation to operate the compressed gas feed valve, the gas vent valves, and optional equipment. Automation may be used to direct the production system to run idle or shut down for a decided period of time, or an automated well-bore fluid level sensor may be employed to slow down, shut down, or speed up the production system, enabling said production system to respond automatically to the hydrocarbon fluid level within the well-bore.

In some cases a vacuum assisted hydrocarbon fluid intake mode is used to draw hydrocarbon fluid into the lower end of the subsurface compressed gas conveyance tubing system as illustrated in FIG. 3. The subsurface production tubing string and\or the subsurface compressed gas feed tubing string or both tubing strings may be evacuated of gas by vacuum pump means, to intake hydrocarbon fluid into the subsurface tubing string(s), the choice being dependant upon equipment or design preference, special conditions or system setup. A dedicated gas compressor and a dedicated vacuum pump may be used within the hydrocarbon production system installation, or a single gas compressor may serve as a gas compressor and as a vacuum pump in the same hydrocarbon production installation. Gas scrubbers and gas filters may be installed into the hydrocarbon production system as desired to protect gas compressors, vacuum pumps and other devices from in-taking earthen particulates, water droplets, hydrocarbon globules or vapours.

The spent compressed gas may be vented from the hydrocarbon fluid storage tank after the fluid purge phase by installing a gas separation conduit inside the hydrocarbon production fluid storage tank. The gas separation conduit preferably should have an inside diameter of sufficient size to conduct the hydrocarbon fluid, by gravity means, to a lower level of the hydrocarbon production fluid storage tank without having excessive spillage of hydrocarbon fluid out the top of the gas separation conduit. In selecting the inside diameter of the gas separation conduit, consideration should be given to the hydrocarbon fluid's expected input volume and viscosity.

The subsurface compressed gas feed tubing string and the subsurface production tubing string may be suspended from or through the wellhead parallel to each other within the well-bore, or one of the subsurface tubing strings may be more conveniently placed inside the other and one tubing string can exit the wellhead through a stuffing box or other suitable pack-off to simplify installation.

The method of the present invention requires the evacuation of excessive gases from one or more of the hydrocarbon production system's components in order for the hydrocarbon production system to function correctly, not explode, and displace hydrocarbon fluid to surface storage efficiently. FIGS. 2 and 4 illustrate gas venting, but FIG. 3 illustrates altered gas venting due to a different equipment setup. A person skilled in the art will appreciate the system's design flexibility and adaptability to direct venting of some or all gases from different outlet positions to various optional gas destinations for further use, or to other gas collecting facilities, or to a vapour recovery system, or to implement design changes to comply with government energy board regulations, environmental, Boiler Branch, safety, or other issues.

When displacing viscose, earthen solids laden or other hydrocarbon fluid from a horizontal well-bore, the lower end of the compressed gas conveyance tubing system may be constructed of an oil field grade of coiled tubing to more easily pass through the dog-legged section of the well-bore and into the horizontal section of the well-bore, as illustrated in FIG. 4. The horizontal section of the subsurface compressed gas conveyance tubing system may be equipped with one or numerous subsurface intake valves to more evenly flood hydrocarbon fluid from a greater span of the subsurface hydrocarbon reservoir, into and through a greater span of casing perforations, sand screens or liner slots that feed hydrocarbon fluid from the subterranean hydrocarbon reservoir into the horizontal well-bore. Due to the horizontal placement of the horizontal section of the subsurface compressed gas conveyance tubing system, reed type intake valves having sufficiently sized ports that close by slight spring pressure or another desired valve may serve as the subsurface intake valves. In some cases, one subsurface intake valve may be considered sufficient.

Within oil fields operating under a water-flood scheme, or wherein the subterranean hydrocarbon reservoir contains and releases hydrocarbon fluid including large volumes of ground water, there is a need to rapidly displace such hydrocarbon fluid from the subterranean reservoir of an oil well to a hydrocarbon production fluid storage tank or other handling facilities at ground surface. By sufficiently increasing the volume and pressure of compressed gas feed, or by reducing the inside diameter of the subsurface production tubing string, the hydrocarbon and water may be purged to surface storage facilities more efficiently, eliminating the problem of compressed gas bubbling to surface through the mostly water column.

In some cases, a build-up of earthen particulates, rock and coal fragments or pyrite balls may accumulate within the lower well-bore and obstruct the flow of hydrocarbon fluid from entering the subsurface lower end of the compressed gas conveyance tubing system. By closing the well-bore's casing gas vent valve, casing gas pressure will build and stop the flow of hydrocarbon fluid from the subterranean hydrocarbon reservoir into the well-bore. By purging all fluid from the compressed gas conveyance tubing system, and then feeding a sufficient volume and pressure of compressed gas from surface, into and through the casing gas vent, through the well-bore, through the subsurface intake valve, and through the subsurface tubing string and surface flow line and into the hydrocarbon fluid storage tank, earthen accumulations within the well-bore may be entrained and carried to surface storage by the resulting compressed gas carrier stream.

A wellhead output gas valve may be added to close off the compressed gas and hydrocarbon fluid flow between the wellhead output and the surface flow line's input end, in order to build sufficient compressed gas pressure within the subsurface compressed gas feed tubing string, and upon opening the wellhead output gas valve, a hydrocarbon fluid column may be rapidly purged, at a considerable velocity, from and through the subsurface production tubing string, through the wellhead, surface flow line, and into the hydrocarbon storage tank. The method is advantageous when there is compressed gas loss due to bubble loss through the production tubing fluid column, or when difficult earthen particulates or rock fragments are to be entrained and carried to surface storage, or when improving heat transfer from compressed gas to hydrocarbon fluid, or when improving the fluid flow shear effect. A rapid fluid column rise to surface and a very gentle “top of fluid column” entry into and through the wellhead, and a gentle “bottom of fluid column” exiting out of the wellhead, may be achieved by calculating and providing the math governing the compression and decompression of gases, subsurface tubing volumes and lengths, fluid column weight and viscosity.

Fluid purge pressures may be minimized by providing more frequent purges and\or the provision of a subsurface production tubing string with a larger inside diameter.

In cases where compressed air is used to purge hydrocarbon fluid from the compressed gas conveyance tubing system to surface storage, the compressor's safety relief valve or other safety means should be set to discharge compressor output to atmosphere or terminate compressed air feed at a pressure below that required to cause a mixture of hydrocarbon fluid, natural gas and air to ignite and combust within the subsurface compressed gas feed tubing string. To further reduce the possibility of combustion, evacuation of natural gas by vacuum pump means may be used to provide an insufficient mix of fuel gas within the subsurface compressed gas feed tubing string when compressed air is fed therein.

In cases where two or more oil wells are closely positioned, as on a pad with multiple oil wells, one gas compressor of sufficient capacity may be very efficiently used to supply the compressed gas for the multiple oil wells. A programmable valve controller may be used to operate as many valves as is required to repetitively cycle each of the oil wells through it's production cycles. As one or more oil wells are in the purge part of their production cycle, one or more other oil wells may be in the fluid intake part of their production cycle, while other oil wells may be waiting idle.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments in which;

FIG. 1 is a schematic illustration of a typical prior art system to displace hydrocarbon fluid from a subterranean hydrocarbon reservoir to surface storage or handling facilities; and

FIG. 2 is a schematic illustration outlining the method of the present invention to displace hydrocarbon fluid from a subterranean hydrocarbon reservoir to surface storage or handling facilities.

The schematic of FIG. 2 additionally illustrates a method to displace a build-up of earthen particulates, rock or coal fragments or pyrite balls from within the lower well-bore to a hydrocarbon production fluid storage tank or other handling facility at surface.

FIG. 3 is a schematic illustration outlining the method of the present invention including the use of an optional vacuum assisted hydrocarbon fluid intake.

FIG. 4 is a schematic illustration outlining the method of the present invention displacing hydrocarbon fluid from a horizontal well-bore.

FIG. 5 illustrates a method to separate spent compressed gas from hydrocarbon fluid as the hydrocarbon fluid is purged from the flow line into the hydrocarbon production fluid storage tank.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to FIG. 1, a typical conventional oil well system includes a production casing indicated by reference numeral 8 which is placed into the earth. Within the casing 8 there is provided a subsurface production tubing string 12 which is basically a length or lengths of conduit coupled together from wellhead 6 to subsurface production pump 15. The system may also include what is commonly known as sucker rods 10. In use, hydrocarbon fluid 13 is fed by means of subterranean hydrocarbon reservoir 16 pressure into well-bore 9 through casing perforations 14 and pumped from well-bore 9 by subsurface production pump 15, into and through production tubing 12, into and through wellhead 6, into and through surface flow line 21, into and through optional surface check valve 20 and into hydrocarbon production fluid storage tank 22. Valve 7 is provided to vent casing gas. Optional surface check valve 20 is provided to prevent stored hydrocarbon fluid 13 from back-flowing from hydrocarbon production fluid storage tank 22 into subsurface production tubing string 12. Vent 23 is provided to vent gas from storage tank 22. The sucker rod drive at surface is not shown.

According to the present invention, as illustrated in FIG. 2, the conventional oil well production system is modified to displace hydrocarbon fluid from an oil well's subterranean hydrocarbon reservoir to a hydrocarbon production fluid storage tank or other handling facility at surface by following the steps of;

providing a compressed gas conveyance tubing system extending from a source of compressed gas at ground surface, through the wellhead and down the well-bore to the approximate subterranean hydrocarbon reservoir depth and returning up out of the well-bore, through the wellhead and into the hydrocarbon production fluid storage tank at surface, with said compressed gas conveyance tubing system including;

a source of compressed gas 1; valve 1a; conduit 2; conduit 3; valve 4; wellhead 6; casing gas vent 7; casing 8; well-bore 9; subsurface compressed gas feed tubing string 11; subsurface production tubing string 12; hydrocarbon fluid 13; casing perforations 14; subterranean hydrocarbon reservoir 16; subsurface intake valve 17; fluid communication port 18; conduit 19; optional surface check valve 20; surface flow line 21; hydrocarbon production fluid storage tank 22; storage tank gas vent 23; optional gas separation conduit 24; gap 25;

flooding hydrocarbon fluid 13 from subterranean hydrocarbon reservoir 16 through casing perforations 14 into well-bore 9, by means of subterranean hydrocarbon reservoir 16 pressure; closing valve 1a; venting excessive gas 1 from subsurface gas feed tubing string 11 through wellhead 6, into and through conduit 2, into and through conduit 3, into and through valve 4 to atmosphere or other gas handling facility; venting excessive gas 1 from subsurface production tubing string 12, into and through conduit 19, into and through optional surface check valve 20, into and through surface flow line 21 and into hydrocarbon production fluid storage tank 22; venting gas 1 from hydrocarbon production fluid storage tank 22 through tank gas vent 23 to atmosphere or other gas handling facility;

flooding hydrocarbon fluid 13 from well-bore 9, by means of hydrocarbon fluid 13 head pressure, into and through subsurface intake valve 17 and into the lower ends of subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12; containing hydrocarbon fluid 13 within subsurface gas feed tubing string 11 and subsurface production tubing string 12 by means of closing subsurface intake valve 17 by gravity or other means; closing valve 4; opening valve 1a;

purging the flood of hydrocarbon fluid 13 contained within the lower ends of subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12, into hydrocarbon production fluid storage tank 22, by means of feeding a sufficient volume and pressure of compressed gas 1 from a source on surface, into and through valve 1a, into and through conduit 2, into and through wellhead 6, into and through subsurface gas feed tubing string 11, into and through fluid communication port 18, into and through subsurface production tubing string 12, into and through conduit 19, into and through optional surface check valve 20, into and through flow line 21, and into hydrocarbon production fluid storage tank 22; optionally separating the mixture of compressed gas 1 and hydrocarbon fluid 13 by feeding hydrocarbon fluid 13 from the output end of conduit 21, through gap 25, into the open top end of and through optional gas separation conduit 24;

venting gas 1 from hydrocarbon production fluid storage tank 22 through storage tank gas vent 23 to atmosphere or other gas handling facility; optionally preventing stored hydrocarbon fluid 13 and gas 1 from back-flowing from hydrocarbon production fluid storage tank 22 into subsurface production tubing string 12 by means of optional surface check valve 20; repeating the hydrocarbon production system cycle for an indefinite period of time; recovering hydrocarbon fluid 13 from hydrocarbon production fluid storage tank 22.

The schematic of FIG. 2 additionally illustrates a means to displace a build-up of earthen particulates, rock and/or coal fragments and/or pyrite balls from within the lower well-bore, to a hydrocarbon production fluid storage tank or other handling facility at surface, comprising the steps of;

stopping the inflow of hydrocarbon fluid 13 into well-bore 9 from subterranean hydrocarbon reservoir 16 by means of feeding compressed gas from a source, into well-bore 9, through casing gas vent 7; closing valve 4; opening valve 1a; purging hydrocarbon fluid from the compressed gas conveyance tubing system to surface storage; closing valve 1a; feeding a sufficient volume and pressure of compressed gas through valve 7 to create a gas carrier stream of sufficient velocity to entrain and carry earthen contaminants and hydrocarbon fluid from well-bore 9, through subsurface intake valve 17, into and through communication port 18, into and through subsurface production tubing string 12, through wellhead 6, into and through conduit 19, optional check valve 20, flow line 21, and into hydrocarbon production fluid storage tank 22 or other handling facility at surface; venting spent compressed gas through storage tank vent 23; continuing the feed of compressed gas until a satisfactory amount of earthen contaminants are displaced from well-bore 9.

The schematic of FIG. 3 illustrates the method of the present invention to displace hydrocarbon fluid from an oil well's subterranean hydrocarbon reservoir to a hydrocarbon production fluid storage tank or other handling facilities at surface, while employing a vacuum assisted hydrocarbon fluid intake to assist the flooding of hydrocarbon fluid from the well-bore into the lower ends of the subsurface gas feed tubing string and subsurface production tubing string, comprising the steps of;

providing a compressed gas conveyance tubing system extending from a source of compressed gas 1 at ground surface, through wellhead 6 and down well-bore 9 to the approximate subterranean hydrocarbon reservoir 16 depth and returning up out of well-bore 9, through wellhead 6 and into hydrocarbon production fluid storage tank 22 at surface, with said compressed gas conveyance tubing system including;

a source of compressed gas 1; valve 1a; conduit 2; conduit 3; valve 4; valve 5; vacuum pump 5a; wellhead 6; casing gas vent 7; casing 8; well-bore 9; subsurface compressed gas feed tubing string 11; subsurface production tubing string 12; hydrocarbon fluid 13; casing perforations 14; subterranean hydrocarbon reservoir 16; subsurface intake valve 17; fluid communication port 18; conduit 19; surface check valve 20; surface flow line 21; hydrocarbon production fluid storage tank 22; storage tank gas vent 23; optional gas separation conduit 24; gap 25;

flooding hydrocarbon fluid 13 from subterranean hydrocarbon reservoir 16 through casing perforations 14 into well-bore 9, by means of subterranean hydrocarbon reservoir 16 pressure;

closing valve 1a; opening valve 4 and valve 5; closing valve 20; evacuating gas 1 from and creating a vacuum within subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12 by means of vacuum pump 5a; venting gas from vacuum pump 5a; drawing and feeding hydrocarbon fluid 13 from well-bore 9 through subsurface intake valve 17 by vacuum means and by hydrocarbon fluid 13 head pressure means, into the lower ends of subsurface gas feed tubing string 11 and subsurface production tubing string 12; closing subsurface intake valve 17 by gravity or other means to contain hydrocarbon fluid 13 within the lower ends of subsurface gas feed tubing string 11 and subsurface production tubing string 12;

closing valve 4 and valve 5; opening valve 1a; purging the flood of hydrocarbon fluid 13 contained within subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12, into hydrocarbon production fluid storage tank 22, by means of feeding compressed gas 1 from a source on surface into and through valve 1a, into and through conduit 2, into and through wellhead 6, into and through compressed gas feed tubing string 11, into and through fluid communication port 18, into and through production tubing string 12, into and through conduit 19, into and through surface check valve 20, into and through surface flow line 21 and into hydrocarbon production fluid storage tank 22; optionally separating the mixture of compressed gas 1 and hydrocarbon fluid 13 by feeding hydrocarbon fluid 13 from the output end of conduit 21, through gap 25, into the open top open end and through optional gas separation conduit 24; preventing stored hydrocarbon fluid 13 and gas 1 from back-flowing from hydrocarbon production fluid storage tank 22 into subsurface production tubing string 12, subsurface gas feed tubing string 11, or vacuum pump 5a, by means of surface check valve 20; venting compressed gas 1 from the upper level of hydrocarbon production fluid storage tank 22 and out of storage tank gas vent 23 to atmosphere or other gas 1 handling facility;

repeating the hydrocarbon production system cycle for an indefinite period of time; recovering hydrocarbon fluid 13 from hydrocarbon production fluid storage tank 22.

According to the present invention, as illustrated in FIG. 4, the conventional oil well production system is modified to displace hydrocarbon fluid from the horizontal well-bore section of an oil well's subterranean hydrocarbon reservoir, to a hydrocarbon production fluid storage tank or other handling facility at ground surface by following the steps of;

providing a compressed gas conveyance tubing system extending from a source of compressed gas at surface, through the wellhead and down the well-bore, beyond the dogleg, to the desired landing point within the horizontal section of the subterranean hydrocarbon reservoir and returning up out of the well-bore, through the wellhead and into the hydrocarbon production fluid storage tank or other handling facilities at surface, with said compressed gas conveyance tubing system including;

a source of compressed gas 1; valve 1a; conduit 2; conduit 3; valve 4; wellhead 6; casing gas vent 7; casing 8; well-bore 9; subsurface compressed gas feed tubing string 11; subsurface production tubing string 12; hydrocarbon fluid 13; casing perforations 14; subterranean hydrocarbon reservoir 16; one or more than one subsurface intake valve(s) 17; fluid communication port 18; conduit 19; optional surface check valve 20; surface flow line 21; hydrocarbon production fluid storage tank 22; storage tank gas vent 23; optional gas separation conduit 24; gap 25;

closing valve 1a; flooding hydrocarbon fluid 13 from subterranean hydrocarbon reservoir 16 through casing perforations 14 into well-bore 9, by means of subterranean hydrocarbon reservoir 16 pressure; venting excessive gas 1 from subsurface gas feed tubing string 11 through wellhead 6, into and through conduit 2, into and through conduit 3, into and through valve 4 to atmosphere or other gas handling facility; venting excessive gas 1 from subsurface production tubing string 12, into and through conduit 19, into and through optional surface check valve 20, into and through surface flow line 21 and into hydrocarbon production fluid storage tank 22; venting gas 1 from hydrocarbon production fluid storage tank 22 through tank gas vent 23 to atmosphere or other gas handling facility;

flooding hydrocarbon fluid 13 from well-bore 9, by means of well-bore hydrocarbon fluid 13 head pressure, into and through one or more than one subsurface intake valve(s) 17 and into the lower ends of subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12; containing hydrocarbon fluid 13 within subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12 by means of closing subsurface intake valve 17 by gravity, spring pressure or other means; closing valve 4;

opening valve 1a; purging the flood of hydrocarbon fluid 13 contained within the lower ends of subsurface compressed gas feed tubing string 11 and subsurface production tubing string 12, into hydrocarbon production fluid storage tank 22, by means of feeding compressed gas 1 from a source on surface, into and through valve 1a, into and through conduit 2, into and through wellhead 6, into and through subsurface gas feed tubing string 11, into and through fluid communication port 18, into and through subsurface production tubing string 12, into and through conduit 19, into and through optional surface check valve 20, into and through surface flow line 21, and into hydrocarbon production fluid storage tank 22;

optionally separating the mixture of compressed gas 1 and hydrocarbon fluid 13 by feeding hydrocarbon fluid 13 from the output end of conduit 21, through gap 25, into the top open end and through optional gas separation conduit 24; venting gas 1 from hydrocarbon production fluid storage tank 22 through storage tank gas vent 23 to atmosphere or other gas handling facility; optionally preventing stored hydrocarbon fluid 13 and gas 1 from back-flowing from hydrocarbon production fluid storage tank 22 into subsurface production tubing string 12 by means of optional surface check valve 20; repeating the hydrocarbon production system cycle for an indefinite period of time;

recovering hydrocarbon fluid 13 from hydrocarbon production fluid storage tank 22.

According to the present invention, as illustrated in FIG. 5, gas is optionally separated from hydrocarbon fluid by following the steps of;

providing optional gas separation conduit 24; placing optional gas separation conduit 24 vertically within hydrocarbon production fluid storage tank 22; feeding hydrocarbon fluid from the output end of conduit 21, downward into the open upper end and through conduit 24, into the lower level of hydrocarbon production fluid storage tank 22; permitting the flow of gas exiting conduit 21 to escape by means of open gap 25 between conduit 21 and conduit 24, into the upper level of the hydrocarbon production fluid storage tank 22; venting gas from the upper level of hydrocarbon production fluid storage tank 22 into and through storage tank vent 23 to atmosphere or other gas collecting or handling facility; providing conduit 24 with an inside diameter of sufficient size to conduct the hydrocarbon fluid, by gravity means, to a lower level of the hydrocarbon production fluid storage tank without having excessive spillage of hydrocarbon fluid out the top of conduit 24.

Claims

1. A method of displacing hydrocarbon fluid which may contain earthen contaminants, from the subterranean hydrocarbon reservoir of an oil well to a hydrocarbon production fluid storage tank or other handling facilities at ground surface, by means of a compressed gas conveyance tubing system, comprising the steps of;

constructing a compressed gas conveyance tubing system extending from a source of compressed gas at surface, through the wellhead and down the well-bore to the approximate subterranean hydrocarbon reservoir depth of the well-bore and returning up out of the well-bore, through the wellhead and into a hydrocarbon production fluid storage tank or other handling facilities at ground surface;

flooding hydrocarbon fluid from the subterranean hydrocarbon reservoir by means of subterranean hydrocarbon reservoir pressure, through the casing perforations and into the well-bore; venting excessive gas pressure from the subsurface section of the compressed gas conveyance tubing system;

flooding hydrocarbon fluid from the well-bore by means of well-bore hydrocarbon fluid head pressure, into the lower subsurface end of the compressed gas conveyance tubing system; closing the compressed gas conveyance tubing system's subsurface intake valve to contain the hydrocarbon fluid within the subsurface section of the compressed gas conveyance tubing system;

purging the contained hydrocarbon fluid from within the subsurface section of the compressed gas conveyance tubing system, into the hydrocarbon production fluid storage tank at ground surface, by means of feeding a sufficient volume and pressure of compressed gas into and through the compressed gas conveyance tubing system, and into the hydrocarbon production fluid storage tank or other handling facilities at surface; venting gas from the hydrocarbon production fluid storage tank or other handling facilities at surface; repeating the hydrocarbon production system's production cycle; recovering hydrocarbon fluid from the hydrocarbon production fluid storage tank or other facilities at ground surface;

lower subsurface end of the compressed gas conveyance tubing system; closing the subsurface intake valve to contain the hydrocarbon fluid within the subsurface section of the compressed gas conveyance tubing system;

purging contained hydrocarbon fluid from within the subsurface section of the compressed gas conveyance tubing system, into the hydrocarbon production fluid storage tank at ground surface, by means of feeding a sufficient volume and pressure of compressed gas into and through the compressed gas conveyance tubing system, and into the hydrocarbon production fluid storage tank or other handling facilities at surface; venting gas from the hydrocarbon production fluid storage tank or other facilities at ground surface; repeating the hydrocarbon production system's production cycle; recovering hydrocarbon fluid from the hydrocarbon production fluid storage tank or other facilities at ground surface;

3. A method of displacing hydrocarbon fluid which may contain earthen contaminants and water from an oil well's well-bore into the lower subsurface section of a compressed gas conveyance tubing system and containing the hydrocarbon fluid therein, comprising the steps of;

providing the apparatus of claim 1; evacuating excessive gas pressure from within the lower subsurface end of the compressed gas conveyance tubing system; flooding hydrocarbon fluid from the well-bore by means of well-bore fluid head pressure, into and through the subsurface intake valve and into the lower subsurface end of the compressed gas conveyance tubing system; closing the subsurface intake valve to contain the hydrocarbon fluid within the lower subsurface end of the compressed gas conveyance tubing system.

4. A vacuum assisted method of displacing hydrocarbon fluid which may contain earthen contaminants and water from an oil well's well-bore into the lower subsurface end of the compressed gas conveyance tubing system, and containing the hydrocarbon fluid therein, comprising the steps of;

providing the apparatus of claim 2; evacuating gas from within the subsurface end of the compressed gas conveyance tubing system by means of a vacuum pump; drawing hydrocarbon fluid from the well-bore, by means of vacuum, into and through the subsurface intake valve and into the lower subsurface end of the compressed gas conveyance tubing system;

closing the subsurface intake valve to contain the hydrocarbon fluid within the subsurface section of the compressed gas conveyance tubing system.

5. A method of displacing hydrocarbon fluid which may contain earthen contaminants and water from the subsurface section of an oil well's compressed gas conveyance tubing system to a hydrocarbon production fluid storage tank or other handling facilities at ground surface, comprising the steps of;

providing the method of claim 1 or claim 2 or claim 6;

purging hydrocarbon fluid and earthen contaminants from within the compressed gas conveyance tubing system into a hydrocarbon production fluid storage tank or other handling facilities at ground surface, by means of feeding a sufficient volume and pressure of compressed gas from a source at surface, through the compressed gas conveyance tubing system and into a storage tank or other handling facilities at surface.

6. A method of displacing hydrocarbon fluid which may contain earthen contaminants from a horizontal well-bore section placed within the subterranean hydrocarbon reservoir of an oil well, to a hydrocarbon production fluid storage tank or other handling facilities on ground surface, comprising the steps of;

providing the method of claim 1 or claim 2; extending the compressed gas conveyance tubing system through the dog-legged section of the well-bore and into the lower subsurface horizontal section of the well-bore; providing the length of the subsurface horizontal section of the compressed gas conveyance tubing system with one or more subsurface intake valves fastened to an external surface of the horizontal section of the compressed gas conveyance tubing system.

7. A method to displace accumulations of earthen particulates or rock or coal fragments or pyrite balls or paraffin from an oil well's well-bore into a hydrocarbon production fluid storage tank or other handling and storage facility at surface, comprising the steps of;

providing the apparatus of claim 1 or claim 2 or claim 6; pressurizing the well-bore; purging hydrocarbon fluid from the compressed gas conveyance tubing system to surface storage, as often as is necessary, to clear a satisfactory amount of hydrocarbon fluid and earthen contaminants from the compressed gas conveyance tubing system; feeding a sufficient volume and pressure of compressed gas from a source at surface, through the casing vent valve and into the well-bore, to create a gas carrier stream of sufficient velocity to entrain and carry earthen well-bore contaminants and hydrocarbon fluid from the lower well-bore, into and through the gas conveyance tubing system, and into the hydrocarbon production fluid storage tank or other handling and storage facility at surface. Continuing the feed of compressed gas until a satisfactory amount of earthen contaminants are displaced from the well-bore.

8. A method to heat hydrocarbon fluid and reduce the viscosity and fluid flow friction factor of hydrocarbon fluid within the subsurface tubulars of an oil well, comprising the steps of;

providing the method of claim 1 or claim 2 or claim 6; heating the hydrocarbon fluid within the subsurface hydrocarbon production tubing string wherein the subsurface hydrocarbon production tubing string is placed concentrically within the subsurface compressed gas feed tubing string and wherein the heated compressed gas fed through the subsurface compressed gas feed tubing string is in contact with the subsurface hydrocarbon production tubing string; permitting heat from the compressed gas to conduct through the wall of the subsurface hydrocarbon production tubing string and into the hydrocarbon fluid, or;

wherein the subsurface compressed gas feed tubing string is placed concentrically within the subsurface hydrocarbon production tubing string, permitting the heat from the compressed gas to conduct through the subsurface compressed gas feed tubing string wall and into the hydrocarbon fluid that is contained within or flowing through the subsurface hydrocarbon production tubing string, or;

wherein the subsurface compressed gas feed tubing string is placed parallel to the subsurface hydrocarbon production tubing string, permitting the heat from the compressed gas to conduct through the subsurface compressed gas feed tubing string's wall; permitting the heat from the compressed gas feed tubing string's wall to radiate heat through the well-bore gas; collecting and conducting the radiated heat into and through the hydrocarbon production tubing string's wall and into the hydrocarbon fluid.