CA1143313A - Method of transporting viscous hydrocarbons - Google Patents

Abstract

Case 6212.1 METHOD OF TRANSPORTING VISCOUS HYDROCARBONS
Abstract of Disclosure An improvement in the method of transporting vis-cous hydrocarbons through pipes is disclosed. Briefly, the improvement comprises adding water containing an effective amount of certain polyethoxy amines to the hydrocarbon. The resulting oil-in-water emulsion has a much lower viscosity and is more easily transported.

Description

- ~9L33~3 Background of the Invention Field of the Invention The invention is in the general field of improved methods of pumping viscous hydrocarbons through a pipe, such as a well-bore or a pipeline.
General Background The movement of heavy crudes through pipes is diffi-cult because of their high viscosity and resulting low mobility. One method of improving the movement of these heavy crudes has included adding to the crude lighter hydro-carbons (e.g. kerosine distillate). This reduces the vis-cosity and thereby improves the mobility. This method has the disadvantage that it is expensive and the kerosine distillate is becoming difficult to obtain.
Another method of improving the movement of these heavy crudes ls by heating them. This requires the instal-lation of expensive heating equipment and thus is an expen-sive process.
The use of oil-in-water emulsions, which use surfac-tants to form the emulsion is known in the art.
U. S. Patent No.'3,425,429 teaches a method of trans-porting viscous hydrocarbons which comprises adding to the hydrocarbon an aqueous solution of the nonionic sur-factant. The nonionic surfactants include those having an amide linkage.
I have discovered a method of transporting viscous hydrocarbons which comprises adding water containing an effective amount of certain polyethoxy amines to the hydro-carbon. My method has the advantage that some of the amines can be readil~ recovered by acidifying the system.
This is not the case for nonionic surfactants that have an amide linkage.
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'' , ; .~ ~'' ', '~ . ' ' . ' '' ~ ' ' ' " ' , ' , ~3313 Brief Summary of the Invention Briefly stated, the present invention is directed to an improvement in the method of pumping a viscous hydro-carbon through a pipe wherein the improvement comprises forming an oil-in-water emulsion by adding to said hydro-carbon from about 10 to about 70 volume percent water containing an effective amount, in the range of about 250 to about 50,000 parts by weight, based on said hydrocarbon, of a surfactant which is a polyethoxy amine selected from the group consisting of (A) amines represented by the formula RNH(CH2CH2)nH

wherein R is a hydrocarbyl group containing from about 6 to about 2a carbon atoms and n is a number in the range of about 5 to about 15, (B) amines represented by the formula (CH2CH2O)yH
R'N ~
(CH2CH2O~zH
wherein R' is an alkyl group containing from about 8 to about 18 carbon atoms or a mixture of saturated and unsaturated straight-chain carboxylates contain-ing from 14 to 18 carbon atoms and is derived from tallow, and y and z are numbers in the range of about 1 to about 3Q, with the sum of y and z being in the range of about 8 to about 60, (C) amines represented hy ths formula (:CH2CH20~ aH
¦ ~ (CH2CH2O)bH
R" N----CH2CH2CH2N \
(CH2CH2O)CH
wherein R" is an alkyl group containing 10 to 18 `

-2a-carbon atoms or a mixture of saturated and unsaturated straight-chain carboxylates containing from 14 to 18 carbon atoms and is derived from tallow, and a, ~ and c are numbers in the range of 1 to 10 with the sum of a, ~ and c being in the range of about 8 to about 20.
Detailed Description Insofar as is known our method is suitable for use with any viscous crude oil. It is well known that crude oils often contain a minor amount of water.
The amount of water which is added to the hydro-carbon is suitably in the range of about 10 to about 70 volume percent based on the hydrocarbon. A preferred amount ^
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1~43313 of water is in the range of about 20 to 50 volume percent.
The water can be pure or can have a relatively high amount of dissolved solids. Any water normally found in the proxi-mity of a producing oil-well is suitable.
The preferred polyethoxy amine surfactants for use in my invention have the formula NH(C1~2CH2)nH

wherein R is a hydrocarbyl group, preferably alkyl, contain-ing from about 6 to about 20, preferably from about 10 -to about 16 and more preferably from about 12 to 14 carbon atoms. Materials can be used wherein the R groups are all the same or a mixture. Usually, a mixture of R groups is used. n is a number in the range of about 5 to about 15, preferably a~out 7.5 to about 15Ø
Polyethoxy amines having the preceding description are available from Rohm and Haas Company, Philadelphia, Pa., under the designation RW-series, e.g. RW-50, RW-75, RW-100, RW-125 and RW-150. The "n values" of these materials is as follows: RW-50 - 5; RW-75 - 7.5; RW-100 - 10; RW-125 - 12.5;
RW-150 - 15.
Suitable polyethoxy amines for use in my invention are represented by the formula ::
~CH2cH2o)yH
R'- N
~ (CH2CH2O)zH

wherein R' is an alkyl group containing from 8 to 18, more su1tably 12 to~l8 carbon atoms, y and z are numbers in the range of about 1 to 30, preferably 5~to 25, with the sum of y~and z being in the range of about 8 to about 60, prefer-abl~about 10~to about 50. R' can be derived from tallowand is a mixture of saturated and unsaturated s-traight-chain carboxylates containing 14 to 18 carbon atoms.
; Amines having the preceding description are avail-able from ~rmak Company under the trademark "ETHOMEEN". It ~;:: : : ~
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11~3313 should be noted that not all "ET}IOMEEN" polyethoxy amines are suitable for use in my invention. Only those meeting the preceding description have been found to be suitable.
Other suitable polyethoxy amines for use in my invention are represented by the formula (C 2c 20)~aH
~-- (CH2CH2) b~
R" - N-- Cll2CH2CH2N \
~CH2CH20) c~l wherein R" is an alkyl group containing 10 to 18 carbon atoms, preferably R" is derived from tallow and is a mix-ture of saturated and unsaturated straight-chain carboxylates containing 14 to 18 carbon atoms, a, b and c are numbers in the range of 1 to 10, preferably 2 to g, with the sum of a, b, and c being in the range of about 8 to about 20, prefer-ably about 10 to about 15.
Amines having the preceding description are avail-able from the Armak Company under the trademark "ETHODUOMEEN".
A suitable amount of polyethoxy amine surfactant is in the range of about 250 to about 50,000 parts per million (ppm) by weight, preferably about 1,000 to about 5,000 parts per~million by weight, based on the hydrocarbon.
A significant feature of my invention is that the p~referred polye~thoxy amine surfactant can be recovered and 25~ reu;sed.~ Acidification to a pH of 3 causes the emulsion to break forming an oil layer and a water layer containing the surf~actant. The aqueous ~olution containing the surfactant can~be used with additional hydrocarbon for purpose of re-ducing its viscosity. If desired, the aqueous layer can be 30;~ ad3usted to a~pH of 11. The surfactant will separate as an oily~layer~on the surface and can be recovered.
In~order to~illustrate the nature of the present invention still more clearly the following examples will be given. It is to be understood, however, that the invention 35 is not to be~limited~to the specific conditions or details . . ~

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1~3313 set forth in these examples except insofar as such limita-tions are specified in the appended claims.
The following materials were used in the tests described herein:
Crude Oil - Goodwin lease crude from Cat Canyon oil field, Santa Maria, California Water - Goodwin synthetic (Water prepared in lab-oratory to simulate water produced at the well. It contained 4720 ppm total solids.) The specific nature and concentration of the various polyethoxy amine surfactants tested are shown in the examples.
Viscosities were determined using a Brookfield viscometer, Model LVT with No~ 3 spindle. The procedure is described below.
Test Procedure .. .. .
Three hundred ml of crude oil, preheated in a large container to about 93C. in a laboratory oven, was transferred to a Waring blender and stirred at medium speed until homogeneous. Stirring was stopped, temperature re-corded, and the viscosity measured using the Brookfieldviscometer at RPM's (revolutions per minute) of 6, 12, 30 and 60. Viscosity was calculated by usiny a multiplication factor of 200, 100, 40 and 20 for the respective speeds tlmes the dial readlng on the viscometer.
~ It may be well to mention that the final result at~6 RPM is an indication of the stability of the solution being tested. ~
` ; The difference in viscosity values on the crude àlone in the e~amples is due to the varying amount of water 30~ naturally pres~ent in the crude. For this reason the surfac-tant;viscosity values was obtained on a crude corresponding ;to~that used;~for~the~crude alone value.
;rn~most o~ the examples only the data for the initial and final~6 RPM are shown since these values are 3S~ sufficient to lnd~icate the improvement in performance ob-tained by using~the surfactants of my invention.

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This example illustrates the improvement obtained using 50 volume percent water contalning varying amounts of different surfactants. The results are shown below.

Initial___ Final Conc. Crudë Crude Plus Crude Crude Plus Surfactant Only Surfactant, Only Surfactant, Surfactantppm cp cp cp cp . ~
RW-75 5,000 3120 80 2600 2640 3,000 5200 40 4600 1260

2,000 3200 40 3000 560 RW-150 5,000 4480 160 4400 1000 5,000 5100 20 4700 600 1,000 7080 60 `6960 460 This example illustrates the improvement obtained using 50 volume percent water containing varying amounts of different surfactants. This example differs from Example 1 in that first 10 percent water was added, a reading was taken, then an additional 20 percent water (total 30 percent) was added, a reading was taken, and then another additional 20 percent water (tot~al~50 percent)~was added and a reading was taken. The results are shown below for the 50 percent water 2~5~ tests.

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Conc. I-nCtlde -Pi s- Crud~e Crude Plus Surfactant Only Surfactant, Only Surfactant, Surfactant ppm cp_ ___cp _ cp cp_ _ RW-75 5,000 29,20180 2480260 5,000* 452010,600 51609200 5,000 286060 2860220 ~W-100 5,000 300p100 2600420 2,000* 51008400 46608800 RW-125 5,000 260040 2480420 2,000* 588012,600 534011,128 RW-150 5,000 324040 3000400 2,000 310060 2800860 1,000* 404010,000 360010,200 * Apparently, this is an anomalous result This example illustrates the improvement obtained using 30 volume percent water containing varying amounts of RW-75 surfactant. The results are shown below.

Initial Final Conc. Crude~Crude Plus Crude~Crude Plus Surfactant Only Surfactant, Only~ Surfactant, Surfactant ppm~ cp ~ cp cp ~c~
RW-75 ~ 5,000 6960 160 5800520 ~ ~ 4,000 3280 160 2680500

3~,000 6060 340 5100460 3,000* 3800 ;13,400 3860~11,600 3,0~00* 5100 6680 41005480 ;2,000* 4540 ~8100 37407400 30~ 1,000* 3360 12,000 280012,200 Apparent1y,;thls is an anomalous result Thl~s~exampl;e~ lustrates the improvement obtained using~30;~volume~percent~water containing varying amounts of 35~ di~fferent sur~factants. This e~ample differs from Example 3 in~that~f~lrst~}0~ Der~ent water was added, readings were taken ~: :: : :

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and then an additional 20 percent water was added (total 30 percent) and readings were taken. The results are shown below for the 30 percent water tests.
Initial_ Final Conc. Crude Crude Plus Crude Crude Plus Surfactant Only Surfactant, Only Surfactant, Surfactant ppm cp _ cp cp cp _ RW-75 5,000 292b 140 2480 260 5,000* 4520 6900 5160 5360 5`,000 2860 S0 2860 260 2,000* 5200 7120 4600 6700 2,000* 2940 7800 2680 7800 ~W-100 5,000 2000 100 2600 180 2,000* 5100 7600 4660 6800 RW-125 5,000 2600 60 2480 140 2,000* 5880 6000 5340 5200 RW-150 5,000 3240 100 3000 160 2,000 3100 140 2800 340 1,000* 4040 7340 3600 7000 * Apparently, this is an anomalous result This example illustrates the improvement obtained using RW-100 at a concentration of 5,000 ppm. Three runs ~; were made. The first at 10 percent water, the second at 30 percent water and the third at 50 percent water. The re-sults are shown below.
Crude Only(l) 10~(2) 30%(3) 50%(4) RPM _ cp _WaterWater Water 6 3000 2000 100 1~0 30~ ~ ~ 12 2850 1050 80 120 ~2740 580 76 88 O.S. 480 80 66 ~ ~2740 552 100 108 35~ 6~ 260~0 760 180 420 O.~S~. = Offscale Temperature 70C.
(2) Temperature 68-70C.
(3) Temperature 72-7~3~C.

(4) Temperature 74C.
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' g EXAMPLES_6~10 These examples are both ilLustrative and compara-tive. They show the viscosity values obtained on a series of ETHOMEEN polyethoxylated amines. The materials tested were the following:

Example Moles of No. ETHOMEEN Chemical Name Ethylene Oxide 6 T/12 bis(2-hydroxye-thyl) tallowamine 2 7 C/15 polyoxyethylene (5) cocoamine 5 8 18/20 polyoxyethylene (10) octadecylamine 10 9 T/25 polyoxyethylene (15) tallowamine 15 18/60 polyoxyethylene (50) -octadecylamine 50 The results are shown below.

Initial Flnal Crude Crude Plus Crude Crude Plus Example Only Surfactant, Only Surfactant~
No. c~ _ cp_ _ cp cp :
6 ~ ~ 2200~ 18,800 170019,400 7 ~ 3200 15,400 250015,200 ~ 8 3800 10Q 2700180 These~examples show clearly that materiaIs contain-in~2 and 5 moles~of ethylene oxide are not effective. By 3D~ ;contrast, materials containing 10 to 50 moles are effective.

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Tilese e~alllp:l.es are :i 1.1 usl-.r.~ ive arld show the i.m-rovemen-t in viscosity values ob-tai.ned usiny two "ETIIODUO~l~EN' polyetho~ylated amines. ~rhe ma-teri.a:ls tc~sted were the Eol-low.illcJ:

Example Moles of No.~THoDuoMrEN _ Chem_cal Nane_ _ _ E hylene Oxide 11 T/20 N,N',N' po].yoxyethylene (10)-N-tallow-1,3 diaminopropane 10 12 T/25 N,N',N' polyo.Yyethylene (15)-N-tallow-1,3 diaminopropane 15 The results are shown bel.ow.
Initial~ Final Crude Crude Plus Crude Crude Plus Example Only Surfactant, Only Surfactant, No. c~ ~ cp cp : Thus, having described the i.nvention in detail, it will be understood:~by~those skilled in the art that certain:variations and modifications may be made without departing from:the~spirit and scope:of the invention as 25:~:de~f~ined~here~in~and in the ~appended claims~

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Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In the method of pumping a viscous hydrocar-bon through a pipe the improvement which comprises forming an oil-in-water emulsion by adding to said hydrocarbon from about 10 to about 70 volume percent water containing an ef-fective amount, in the range of about 250 to about 50,000 parts by weight, based on said hydrocarbon, of a surfactant which is a polyethoxy amine selected from the group consist-ing of (A) amines represented by the formula RNH(OCH2CH2)nOH

wherein R is a hydrocarbyl group containing from about 6 to about 20 carbon atoms and n is a number in the range of about 5 to about 15, (B) amines represented by the formula wherein R' is an alkyl group containing from about 8 to about 18 carbon atoms or a mixture of saturated and unsaturated straight-chain carboxylates contain-ing from 14 to 18 carbon atoms and is derived from tallow, and y and z are numbers in the range of about 1 to about 30, with the sum of y and z being in the range of about 8 to about 60, (C) amines represented by the formula wherein R" is an alkyl group containing 10 to 18 carbon atoms or a mixture of saturated and unsatu-rated straight-chain carboxylates containing from 14 to 18 carbon atoms and is derived from tallow, and a, b and c are numbers in the range of 1 to 10 with the sum of a, b and c being in the range of about 8 to about 20.

2. The improved method of Claim 1 wherein, in the amine of group (A), R is an alkyl group containing from about 10 to about 16 carbon atoms and n is a number in the range of about 7.5 to about 15.

3. The improved method of Claim 1 wherein, in the amine of group (B), R' is an alkyl group containing from 12 to 18 carbon atoms and y and z are numbers in the range of 5 to 25, with the sum of y and z being in the range of about 10 to about 50.

4. The improved method of Claim 1 wherein, in the amine of group (B), R' is a mixture of saturated and un-saturated straight-chain carboxylates containing from 14 to 18 carbon atoms and is derived from tallow, and y and z are numbers in the range of 5 to 25, with the sum of y and z being in the range of about 10 to about 50.

5. The improved method of Claim 1 wherein, in the amine of group (C), R" is a mixture of straight-chain carboxylates containing from 14 to 18 carbon atoms and is derived from tallow and a, b and c are numbers in the range of 3 to 8, with the sum of a, b and c being in the range of about 10 to about 15.

6. The improved method of any one of claims 2, 4 and 5, wherein the amount of water added to said hydrocar-bon is in the range of about 20 to about 50 volume percent.

7. The improved method of any one of claims 2, 4 and 5, wherein the amount of water added to said hydrocarbon is in the range of about 20 to about 50 volume percent, and the amount of polyethoxy amine surfactant is in the range of about 1,000 to about 5,000 parts per million by weight based on said hydrocarbon.

8. The improved method of any one of claims 2, 4 and 5, wherein the hydrocarbon is a crude oil, the amount of water added to said hydrocarbon is in the range of about 20 to about 50 volume percent, and the amount of polyethoxy amine surfactant is in the range of about 1,000 to about 5,000 parts per million by weight based on said hydrocarbon.