US1462288A - Process and apparatus for extracting hydrocarbons from oil wells and oil-bearing strata - Google Patents

Description

July 17, 1923 1,462,288

W. J. KNOX PRocEss AND APPARATUS Fon EXTRACTING HYDRocARBoNs FROM on. wELLs v AND on. BEARING sTRA'rA Filed April 10. 1919 VENTOR.

ATTORNEY;v

Patented July 17, 1923.

UNITED STATES 1,462,288 PATENT oFFlcE.

WILLIAM JoHN xNox, or NEW Yoan, N. Y., assIeNoa, BY IIEsNE AssIeNuENrs, 'ro I sAID xNox AND ARTHUR aoBINs sPEEa, or BaoNxvILLE, Naw You.

PROCESS AND APPARATUS FOB EXTBACTING BYDBOCABBOS FROM OIL WELLS m OIL-BEARING'A STBATA.

Application led April 10, 1919. Serial'lo. 288,928.

To all wlwmz'tmaiyco em:

Be it known that I, ILLIAM JOHN KNox,

a citizen of the United States, residing at New York city, in the county and State of New York, have invented certain new and useful Improvements in Processes and Aparatus for ExtractingHydrocarbons from il Wells and Oil-Bearing Strata, of which the following is a specification.

My invention relates broadly and generally to new and useful improvements in proc esses and apparatus .whereby the oil and other -hydrocarbons existing in subterranean strata and sands can be more fully and l5 economically recovered than by otherexisting methods, and whereby the rate of flow of the oil and other hydrocarbons can be greatly augmented, and furthermore, wherebyv that portion of 'the oil which is ordinarily non-recoverable, is by the use of my invention rendered available and is thereby recovered.

. In order to convey a clear understanding of the subject, I will describe the initial '.25 conditions existing before a well is drilled and the changes in these conditions which occur during the life of the well. The oil is contained in solid rock strata or densely compacted sand, and would not flow freely unless subjected to the expelling force of as or other pressure. In some cases the oil 1s subjected to a hydrostatic pressure, but in all cases the .main pressure is caused by condensed vapors and absorbed gases. At

the beginning this pressure may be several lhundreds of pounds and this locked-in pressure in the dense sand indicates a condensation to the liquid state .of all the lighter 'hydrocarbon vapors and a very high per- 40 centage of absorption of the hydrocarbon gases in the oil, in acordance with the well known laws of physics. The pressure is not so much on the oil as, in reality, within the oil. n

When the hole is drilled through the rock capping and into the oil-sand, the oil begins to liberate 'the ases with which it is char ed and the lique' ed volatile hydrocarbons gbein to volatilize with great force and the U0 oil is driven forward by the movement of the gas, the expelling action beginning near the .hole and gradually extending further away into the rock. As the light vapors and oils escape, the oil becomesthicker an more viscous .and is forced through the fine interstices of the rock with greater diiiiculty. Eventually the oil'becomes so viscous, t e gas pressure so weak and the capillary yresistance so' great that the well. ceases almost entirely to yield oil, as the force of gravity is not sufficient to cause it to flow in its thickened condition. It is due to this altered conditionof the oil in the sand that oilfwell engineers and geologists have reason to believe that much less than fifty per cent of the oil actually in thestrata is ever recovered. vIt is the intent of my process, not only to augment -the usual flow of the oil, but to recover the larger portion of this residue oil, and to extend the area of strata from which oil is recoverable to agreater distance from the well.

One of the important objects of my invention is to greatly increase the Aflow of oil over long periods of time` and from greater distances from the well, and is intended to be used continuously or at frequent intervals, preferably not as a separate operation from 'the oilpumping, but co-incident therewith, and in integral combination. I have described above the viscous and sluggish condition of the oil in the strata after the excessive vapor and gas pressure have been diminished. i It is a well known fact that a small rise in temperature will greatly decrease the viscosity of lan oil and render it extremely fluid; parain wax, itself, which is one of the residues left in the rock, and is known to cause a retardation of flow, melts at 125 F. or thereabouts.. Now the4 temperature at the bottom of an oil well in the strata is not as a rule over 60 to 70 and this is not suflicient to render the heavy parailin compounds Huid, but an increase in temperature y my process to 125 or to 150 in the strata causes the oil to How readily, no matter how thickened it has become. By my method the rock or sand at the bottom of the well, and for extended distances around it, will be heated to the above temperatures in an economical manner, and the oil caused to How freely and abundantly, even in the case of ,wells that have practically ceased to produce oil, and in addition, large out my invention, conduct In carrying1 d heat to the o1 -bearing strata at the bottom 105, amounts of gases and vapors are roduced.

of the Well by pumpingthe fluid contents of the well by means of the oil-well pump up to and through a heating device preferably external to the Well, then I return this heated or heat-carrying fluid, which is ordinarily crude oil from the well, back into the Well by conducting it preferably by suitable pipe connections to the oil-Well casin head, whence it falls by gravity again to t e bottom of the Well. rl`his operation may be a continuous one, the oil-well pump, the heat generating device and the oil well being cyclically connected. To the extent that the heat is absorbed by the sand or well, the oil or heat carrying fluid Will return to the heating device at a diminished temperature,

but as the well and strata become warm the oil will return at a continuously higher temperature, so that less heat energy will be required to maintain a predetermined maximum temperature in the well. The rock or sand in the oil bearing strata are very slow conductors of heat, and it is not economical to supply heat faster than it can be abs 'sorbed To control this heat supply a thermostatic regulator is preferably made a part of the heat generating device, which can be adjusted so as to heat the oil to a predetermined maximum temperature and which automatically cuts ott the supply of fuel to the burners of the heat generating device, as the oil returning from the Well becomes gradually hotter, thus using only such an amount of fuel as necessary to raise the oil from its returning temperature to the predetermined maximum temperature. When the oil approaches the predetermined maximum temperature when returned from the well, because the well and strata have become too hot to absorb more heat, then the thermostatic regulator Aautomatically turns off all the fuel supply to the burners, with the exception of a small pilot flame. The heat in the well will continue to penetrate into the strata for a considerable period of time, but the amount of heat required to maintain the well at the predetermined balanced temperature is very small. Because the oil-bearing strata is overlaid with several hundred feet. of insulating material, when heat has been once absorbed into the rock strata it remains there indefinitely or for a considerable period of time, as the leakage or depletion of heat from the well vand strata is represented directly by the amount of heat carried in the oil piped off for storage and sale. This amount of heat leakage is extremel small. The specific heat of petroleum oil is less than 0.5 of a British thermal unit per degree Fahrenheit for one pound of oil, and the heat lost may be taken as the difference between the groundtemperature, say and the outgoing oil temperature'of 125 or 60. Calling the weight of a barrel of oil 300 pounds.

this represents 9,000 heat units or the equivalent of only nine feet of the lowest quality of natural gas. rlhis illustration is given to show the low cost of -maintaining the well in a balanced heat condition and of heating the outgoing oil.

Another advantage and object of the invention is not only to increase the How and yield of the well, but to render, as indicated above, thick viscous oils thinner, 'so that they will iow freely through the delivery pipes to the crude oil storage tanks, and this feature is especially valuable in cold climates.

Another valuable product of an oil well is the casing-head or hydrocarbon gas carrying .large amounts of volatile vapors which are, utilized in compression and absorption plants for the making of gasoline. The amount of casing-head gas is greatly increased by this process as well as its content of gasoline making hydrocarbons. This object and result is claimed as a valuable feature of my invention. Incidentally, the total cost of installation and maintenance of the apparatus and process is paid for by the increased gas production` without regard to the increased amount of casing-head gasoline produced. 4

In the accompanying drawing to be taken as a part of this specification, Ihave shown an apparatus which l have invented for elticiently carrying out the said process constituting my invention, in which drawing, said apparatus is shown in side elevation and partly in longitudinal section` some parts being indicated diagrammatically.

Referring to the drawings by characters of reference, 1 designates a Well casing which may be of any of the Well known constructions without departing from my invention.

2 designates the earth stratum, or socalled oil-sand, into which the casing is driven or lowered.I

The well casing may be provided with thel usual easing-head 2 supporting a pump tubing 3, in which is arranged a. pump rod l :for operating a pump piston 5, all of which may be of any well known or suitable construction. The pump rod 4 projects above the casing and is connected to a suitable lever mechanism 6 by means of which the pump is operated or reciprocated to elevate the oil from the well. The pump tubing 3 is connected by an outlet pipe 7 to a receiving chamber 8 into which the oil is pumped by means of the pump mechanism heretofore described. The receiving chamber 8 opens at its upper portion into an outlet pipe 9 through which the oil Hows into a heating coil l0 arranged within the casing of a heater 11 provided with a. suitable burner 12. The receptacle or chamber 8 is provided ...preferably with a central flue 13 leading to a an outlet pipe to the interior of the Well casing 1, the said pipe 15 being projected through the casing-head 2a into the interior of the casing, as at 16, for the purpose stated.

Theoil elevated by the pump piston passes through the pipe 7, is heated` by the heat- I ing element comprising preferably thechain- 4transmitted to anysuitable `collector', or "means for treating `said gas, for example,

ber 8,and coil 10, Whereuponfsaid oil in its vheated condition is flowed into the casing to impart and maintain the desired temperature in the Welland in the oil-bearingstratum.-

Connected to the casing-head 2a'is a pipe section 17 which opens into `a pipe 18 by means `of ,which casing-head gas may be an apparatus for recovering hydrocarbon constituents from said gas. This pipe 18 i'iiay4 be connectedv by- 4a branch pipe 119 to the burner 12, said ypip'e 19- being con'- trolled preferably by a'therinostatic valve 20 cnnec ed by a conductor 21 to -a themo. Acouple or other jthermostatic device 22 s ubjected to the temperature of the oil flowing from the coil 10, the arrangement being such that -said valve 20- is controlled to regulate the amount offfuell gas fed to the burner 12, in order to maintain the oil passingfrom the heating device at a constant predetermined.

maximum temperature irrespective of the amount of oililovving through the heating device. rlhe upper portion of the heating chamber 8 may be connected by a vapor pipe 23 to the said pipe v18 so that the vapors given oflithe oil in said chamber n'iayfbedelivered to the said pipe 18, and a portion burned in the burner 12, or passed )Vith the casing-head gasto suitable storage or treatment. The pipe 7 is connected to a pipe 24 discharging into a collector or storage ltanlr 25. The pipe 7 is provided with a controlling valve 26 between the heater and said pipe 24, and the pipe 24C is provided with a Ivalve 27. By positioning 'the valves 26 and 27, the entire body of oil may be' caused to pass through the heating device and be heated therein, in order to carry heated oil back to thewell casing,4ora portion of the oil pumped from vthe Well may be diverted through the pipe 24;- into the storage tank -or collector 25, or the entire body of oil 1` pumped from the vwell maybe delivered to the storagejor collector 25.

By means of the thermostatic regulator, the temperature of: the oil passing from the l heating device to the Well may be maintained at a constant predetermined maximum temperature, irrespective of the amount of heretofore described.

oil 'which Hows through the heater.A As the process continues, the-heat ofthe .oil in the `well will' be increased,and the thermostatic regulator in responseto these v.increases of heating-ill regulate the supply ofduel to the burnersy 'so asto diminish the supply as the heat requirement is lessened. i

The oil heater may be provided with a v releasevalve 28 in order to permit the escape of vapors generated 'therein through'the pipe connection 2 3 to the casing-head gas delivery pipe 18 from the Well casing, in order that the gas collected inthe oil chamber 8 may pass to the casing-head and thereby be conserved.

l preferably provide a drain valve 29 at the bottom of' the vchamber 8, in order that Water and sludge Which'collects in the bot.-

dscharging into the chamber 8 at an opening above the bottom thereof, and arranging the outlet t0 the pipe 9 abovefsaidinlet from the pipe 7 and toward the top of' the heater 8, 'the said heater 1'will serve vas 'a separator of Water and sediment carried .by the eil from the well, which water and sediment may be drawn oil` through the said drain 29,

ln operation, the process lemllaodying my invention is performed by the above. described apparatus as follows:` The oil pumped from the vvell is elevatedthrough delivery pipe,

tomof said chamber may be drawn off. vBy -having the inlet pipe iomthe oilyvvell pump1 the pump tubing 3 and delivered through v the pipe 7 to the lchamber' 8 Where it is preferably initially heated, and Water and sludge separated therefrom, said oil passing from said chamber into the pipe 9, whence it flows into the heating coil 10, and is further heated and flows fromsaid coil into the pipe 15, whence it is delivered into the Well casing from the outlet pipe 16. By this op-f eration, the-,oil elevated from the Well isl heated, and operating asaY heat carrier dovv's back into the Well, thereby lserving to 'transmit theheat to the hydrocarbon oils in the AWell and the oil-bearing strata, for purposes hereinbefore set forth.

ln the preferred embodiment of the process,l l preferably employ the' hydrocarbon' fluid contents o the vvell being treated as the heat transmitting medium, but l desire it understood that l do not liniitrnyselfto the use of the hydrocarbons originating in the `Well being treated, but may, under certain circumstances, employ huid hydrocarbon from another source-in order-'to ini'- tiate a proper circulation and transmission of heat to the oil in the Well, and the oil bearing strata. This may be advisable in cases where the hydrocarbon contents of the be advisable Where the hydrocarbon contents of the Well havesolidified to the extent that vvell are not suiicient in .amount to serve efficient-ly as the heat carrier. lt may also theycannotfbe satisfactorily pumped 'until from any'suitable source, for example, the container 8 designed to -contain sulicient o1l for the purpose', or the?l oil maybe taken.

from another Well, and pumped to the Well casing from which it may be circulated in the manner heretofore described.

What I claimA and desire to secure by Letters Patent ot-the United States is 'A l. The method of increasing the production of an oil Well consisting in maintaining the oil bearing stratum adjacent the Well at a temperature above normal and suiiiciently high to reduce the viscosity of the oil therein and facilitate its How toward the. well by discharging heated liquid into the Well in a sumcientlyA continuous supply vto maintain the desired temperature in said stratum and removing the same in 'the usual pumping operation. Y f' 2. The method of increasing the production of an oil Well consisting in maintaining the oil bearing stratum adjacent the .vell at a temperature above normal and suiiiciently high to reduce the viscosity ot the oil therein' and facilitate its iiqiv toi'vard the Well by heating crude oil, discharging'such heated oil into the-Well in a suiiiciently continuousI Vsupply to maintain the said stratum-at the desired temperature and removing said oil together. with the new oil produced in the Wellin the usual pumping operation. l3. Themethodof increasing the production of an oil Well consisting in maintaining the olbearing stratum adjacent the well at a temperature Aaboife'normal and sufficiently high to reducethe viscosity of the oil therein and facilitate its How toward the Well by heating more or less of the crude oil obtained from the Well, delivering the heatedoil into the Well in a sufficiently continuous Lacasse Supply to maintain said stratum at the desired temperature and removing the oil in -the usuail-pumping operation.

high toreduce the viscosity of the oil therein andfac-ilitate its How toward the Well by heating more or less of the crude oil obtainedlfrom' the well-to a predetermined temperature, delivering the heated oil into` the Well in a sufficiently continuous supply to maintain said stratum. at the desired temperature and removing the oil in the usual pumping operation.

5. In an appara-tus for increasing the production of an oilvvell, the combination with the Well and the oil pump therein oi' an oil heater outside the weli, means for conveying oil from the pump to the oil heater, and means-for conveying oil from the heater and delivering it into the Well, for the purpose set forth. (iin-an apparatus for increasing the production ofan oil Well, the combination with the Well and the oilv pump therein of an oil heater outside thee well, means for conveying oil from the pump to the oil heater, means for regulating said heater whereby the temperature of the oil discharged there- .'From will be substantially uniform, and means for conveying oil from the heater and delivering it into the ivell, for the purpose set forth.

In testimony Where-of l have hereunto signed my name in the presence of the subscribing Witnesses.

WILLiAM AJonN KNOX.

Witnesses:

ADELE S. EBERHARDT, CQG. HEYLMUN.

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