Abstract:
An improvement in the method of transporting viscous hydrocarbons through pipes is disclosed. Briefly, the improvement comprises adding water containing an effective amount of a combination of an ethoxylated alkyl phenol and a sodium or ammonium salt of an ethoxylated alcohol sulfate. The resulting emulsion has a lower viscosity and is more easily transported.

Description:
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 difficult 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 hydrocarbons (e.g. kerosine distillate). This reduces the viscosity 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 is by heating them. This requires the installation of expensive heating equipment and thus is an expensive process. 
     Still another method of moving heavy crudes through pipes uses oil-in-water emulsions which use surfactants to form the emulsions. 
     I have found that use of an aqueous solution containing a combination of an ethoxylated alkyl phenol and an ethoxylated alcohol sodium sulfate provides better viscosity reduction than use of either material alone. 
     BRIEF SUMMARY OF THE INVENTION 
     Briefly stated, the present invention is directed to an improvement in the method of pumping a viscous hydrocarbon through a pipe wherein the improvement comprises forming an oil-in-water emulsion by adding to said hydrocarbon from about 20 to about 80 volume percent water containing an effective amount of a combination of an ethoxylated alkyl phenol and a sodium or ammonium salt of an ethoxylated alcohol sulfate. 
     The specific nature of the ethoxylated alkyl phenol and the ethoxylated alcohol sodium sulfate are provided in the detailed description. 
     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 hydrocarbon is suitably in the range of about 20 to about 80 volume percent based on the hydrocarbon. A preferred amount of water is in the range of about 30 to 60 volume percent. The water can be pure of can have a relatively high amount of dissolved solids. Any water normally found in the proximity of a producing oil-well is suitable. 
     Suitable ethoxylated alkyl phenols are mono- or dialkyls, wherein each alkyl group contains from about 8 to 12 carbon atoms, and which contain from about 35 to about 100 ethoxy groups, preferably from about 40 to about 70 ethoxy groups. The preferred ethoxylated alkyl phenols are monooctyl phenol and monononyl phenol. 
     My invention uses certain specific ethoxylated alcohol sulfates which can be represented by the following structural formula 
     
         [CH.sub.3 (CH.sub.2).sub.x CH.sub.2 (OCH.sub.2 CH.sub.2).sub.n OSO.sub.3 ]M 
    
     wherein X is an integer in the range of about 8 to about 20, preferably from about 10 to about 16, n is a number in the range of about 1 to about 50, preferably about 2 to about 30, more preferably about 3 to about 12, and M is NH 4  or Na, but preferably is sodium. 
     The alcohol moiety of the ethoxylated alcohol sulfate can be an even or odd number or a mixture thereof. Preferably, the alcohol moiety is an even number. Also, preferably, the alcohol moiety contains 12 to 18 carbon atoms. 
     Suitable ethoxylated octyl phenols are available from Rohm and Haas Company, under the tradename &#34;TRITON&#34;, for example, TRITON X-405, containing 40 moles of ethylene oxide, and TRITON X-705, containing 70 moles of ethylene oxide. 
     Suitable and preferred amounts of the ethoxylated alkyl phenol and the ethoxylated alcohol sulfate, based on the hydrocarbon, are shown below. 
     
         ______________________________________             (parts per million)             Suitable Preferred______________________________________Ethoxylated alkyl phenol               50-10,000  100-1,000Ethoxylated alcohol sulfate               50-10,000  100-1,000______________________________________ 
    
     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 is not to be limited to the specific conditions or details set forth in these examples except insofar as such limitations 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, Calif. 
     Water--Goodwin synthetic (Water prepared in laboratory to simulate water produced at the well. In contained 4720 ppm total solids.) 
     The specific composition of the surfactant materials tested will be given 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 93° C. in a laboratory oven, was transferred to a Waring blender and stirred at medium speed until homogeneous. Stirring was stopped, temperature recorded, and the viscosity measured using the Brookfield viscometer at RPM&#39;s (revolutions per minute) of 6, 12, 30 and 60. Viscosity was calculated by using a multiplication factor of 200, 100, 40 and 20 for the respective speeds times the dial reading on the viscometer. 
     It may be well to mention that the fuel result at 6 RPM is an indication of the stability of the solution being tested. 
     The difference in viscosity values on the crude alone in the examples is due to the varying amount of water naturally present in the crude. For this reason the viscosity value of the crude alone was obtained in each example. The crude corresponded to that used in combination with the aqueous surfactant. 
    
    
     EXAMPLE 1 
     This example is comparative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude oil and 50 volume percent water which contained 500 ppm of an ethoxylated octyl phenol containing 70 moles of ethylene oxide. 
     The results are shown in Table I. 
     
                       TABLE I______________________________________            Crude Oil Plus 300 ml Goodwin            Synthetic Water ContainingCrude Oil Alone  500 ppm Of The Described(300 ML)         Ethoxylated Octyl PhenolDial       Viscosity Dial Reading                            Viscosity cpRPM   Reading  cp        No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    18       3,600     0.5   12    100   2,40012    38       3,800     1     18    100   1,80030    93       3,720     1     32     40   1,28060    Offscale --        3     56     60   1,12030    93       3,720     1.5   29     60   1,16012    37       3,700     1.5   13    150   1,300 6    18       3,600     1.75   8    350   1,600Test Temperature 91° C.            79° C.(1), 71°  C.(2)______________________________________ *After (2min) delay. Emulsion contained very little foam. 
    
     EXAMPLE 2 
     This example is comparative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude oil and 50 volume percent water which contained 600 ppm of the sodium salt of a sulfated ethoxylate derived from a C 12  -C 14  linear primary alcohol blend and containing 7 moles of ethylene oxide. 
     The results are shown in Table II. 
     
                       TABLE II______________________________________            Crude Oil Plus 300 ml Goodwin            Synthetic Water ContainingCrude Oil Alone  600 ppm Of The Described(300 ml)         Sulfated EthoxylateDial       Viscosity Dial Reading                            Viscosity cpRPM   Reading  cp        No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    20       4,000     0.6   11    120   2,20012    39.5     3,950     1.5   13    150   1,30030    95       3,800     2.7   21    108     84060    Offscale --        4     34     80     68030    89       3,560     4     23    160     92012    34.5     3,450     3.5   14    350   1,400 6    17       3,400     3.7   12    740   2,400Test Temperature 93° C.            71° C.(1), 66°  C.(2)______________________________________ *After (2min) delay. Blender jar full of foam. 
    
     EXAMPLE 3 
     This example is illustrative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude oil and 50 volume percent of water containing 250 ppm of the surfactant material of Example 1 and 250 ppm of the surfactant material of Example 2. 
     The results are shown in Table III. 
     
                       TABLE III______________________________________            Crude Oil Plus 300 ml Goodwin            Synthetic Water ContainingCrude Oil Alone  500 ppm Of The Described(300 ml)         CombinationDial       Viscosity Dial Reading                            Viscosity cpRPM   Reading  cp        No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    14.4     2,880     0.2   0.2   40    4012    24.7     2,470     0.3   0.3   30    3030    61.7     2,456     0.6   0.6   24    2460    Offscale --        0.8   1.1   16    2230    57.4     2,296     0.7   0.6   28    2412    21.5     2,150     0.3   0.2   30    20 6    11       2,200     0.2   0.1   40    20Test Temperature 100° C.            82° C. (1), 77° C. (2)______________________________________ *After (2min) delay. Little or no foam. 
    
     EXAMPLE 4 
     This example is comparative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude oil and 50 volume percent of water containing 125 ppm of the surfactant of Example 2 and 125 ppm of an ethoxylated octyl phenol containing 30 moles of ethylene oxide. 
     The results are shown in Table IV. 
     
                       TABLE IV______________________________________            Crude Oil Plus 300 ml Good-            win Synthetic Water Con-Crude Oil Alone  taining 250 ppm Of The(300 ml)         Described Combination Dial     Viscosity Dial      ViscosityRPM   Reading  cp        Reading   cp______________________________________ 6    31.2     6,240     14        2,80012    59.4     5,940     29.5      2,95030    Offscale --        46        1,84060    Offscale --        76        1,52030    Offscale --        40.7      1,62812    62.8     6,280     17.6      1,760 6    31.3     6,260     9.4       1,880Test Temperature 78° C.            Test Temperature 71° C.______________________________________ 
    
     EXAMPLE 8 
     This example is comparative and shows the viscosity values obtained on a combination of 50 volume percent crude oil and 50 volume percent of water containing 250 ppm of an ethoxylated octyl phenol containing 40 moles of ethylene oxide. 
     The results are shown in Table V. 
     
                       TABLE V______________________________________  Crude Oil Plus 300 ml Goodwin Synthetic Water  Containing 250 ppm Of The Described  Ethoxylated Octyl PhenolRPM      Dial Reading    Viscosity cp______________________________________ 6       4               80012       7.3             73030       6.4             25660       6.6             13230       5               20012       7.5             750 6       10              2,000  Test Temperature 79° C.______________________________________ 
    
     EXAMPLE 6 
     This example is illustrative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude oil and 50 volume percent of water containing 125 ppm of the surfactant of Example 2 and 125 ppm of the ethoxylated octyl phenol containing 40 moles of ethylene oxide of Example 5. 
     The results are shown in Table VI. 
     
                       TABLE VI______________________________________            Crude Oil Plus 300 ml Good-            Win Synthetic Water Con-Crude Oil Alone  taining 250 ppm Of The(300 ml)         Described Combination Dial     Viscosity Dial        ViscosityRPM   Reading  cp        Reading     cp______________________________________ 6    39.7     7,940     0.3         6012    76.7     7,670     3           30030    Offscale --        1.5         6060    Offscale --        2.8         5630    Offscale --        2           8012    67.8     6,780     0.6         60 6    33       6,600     0.3         60Test Temperature 86° C.            Test Temperature 72° C.______________________________________ 
    
     EXAMPLE 7 
     This example is illustrative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude oil and 50 volume percent water containing 125 ppm of the surfactant of Example 2 and 125 ppm of an ethoxylated monononyl phenol containing 50 moles of ethylene oxide. 
     The results are shown in Table VII. 
     
                       TABLE VII______________________________________            Crude Oil Plus 300 ml Good-            win Synthetic Water Con-Crude Oil Alone  taining 250 ppm Of The(300 ML)         Described Combination Dial     Viscosity Dial        ViscosityRPM   Reading  cp        Reading     cp______________________________________ 6    56.8     11,360    0.3         6012    Offscale --        0.3         3030    Offscale --        1.5         6060    Offscale --        2           4030    Offscale --        3           12012    Offscale --        0.5         50 6    61.5     12,300    0.3         60Test Temperature 70° C.            Test Temperature 66° C.______________________________________ 
    
     Thus, having described the invention 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 defined herein and in the appended claims.