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 an ethoxylated polypropylene glycol. 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. 
     Still further, it is known to reduce the viscosity of viscous crudes by the use of an aqueous solution containing an ethoxylated alkyl phenol or this material in combination with a copolymer of ethylene and a polar organic compound (e.g. as acetate). 
     I have found that use of an aqueous solution containing a combination of an ethoxylated alkyl phenol and an ethoxylated polypropylene glycol provides better viscosity reduction than use of either material alone. Furthermore, certain combinations of ethoxylated alkyl phenol and ethoxylated polypropylene glycol provide even better results. 
     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 an ethoxylated polypropylene glycol. 
     The specific nature of the ethoxylated alkyl phenol and ethoxylated polypropylene glycol 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 or 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 20 to about 100 ethoxy grouups, preferably from about 30 to about 70 ethoxy groups. The preferred ethoxylated alkyl phenol is a monoalkylphenol containing 8 to 10 carbon atoms in the alkyl group. 
     Suitable ethoxylated polypropylene glycols are those containing from about 10 to about 60 weight percent ethylene oxide and having a molecular weight in the range of about 1300 to about 2900. The preferred ethoxylated polypropylene glycols are those containing from about 20 to about 50 weight percent ethylene oxide and having a molecular weight in the range of about 1500 to about 2500. 
     While any ethoxylated alkyl phenol meeting the foregoing description is suitable commercial materials are available from Thompson-Hayward Chemical Company under the tradenames T-DET N-20, T-DET DD-30, T-DET N-407 and T-DET N-507. 
     While any ethoxylated polypropylene glycol meeting the foregoing description is suitable, commercial materials are available from Wyandotte Chemicals Corp., a division of BASF, under the tradename &#34;Pluronic&#34; (e.g. Pluronic L-44). 
     Suitable and preferred amounts of the ethoxylated alkyl phenols and ethoxylated polypropylene glycols, based on the hydrocarbon, are shown below. 
     
         ______________________________________            Suitable Preferred            (parts per million)______________________________________Ethoxylated alkyl phenol              50-10,000  100-1,000Ethoxylated polypropyleneglycol             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, California 
     Water--Goodwin synthetic (Water prepared in laboratory to simulate water produced at the well. It 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 final 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 and 50 volume percent water which contained 500 ppm of an ethoxylated nonyl phenol containing 40 moles of ethylene oxide per mole of nonyl phenol (T-DET N-407). 
     The results are shown in Table 1. 
     
                       TABLE 1______________________________________        Goodwin Crude Oil Plus        300 ml Goodwin SyntheticGoodwin Crude        Water Containing 500 ppmOil Alone    T-DET N-407(300 ml)             Dial Reading                            Viscosity cpRPM   Viscosity cp            RPM     No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    4,400       6      1     13    200   2,60012    4,450      12      1.75  15    175   1,50030    4,000      30      2     13     80   52060    Off Scale  60      4     12     80   24030    3,800      30      2.5   11.5  100   46012    3,750      12      1.75  7     175   700 6    3,700       6      1.5   4.8   300   960Test Temperature        Test Temperature °F. 165.sup.(1) 155.sup.(2)°F. 195______________________________________ *Stopped stirrer, then waited two minutes before starting viscosity measurements. .sup.(1) temperature  first test .sup.(2) temperature  second (delayed) test 
    
     EXAMPLE 2 
     This example is comparative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude and 50 volume percent water which contained 500 ppm of an ethoxylated nonyl phenol containing 50 moles of ethylene oxide per mole of nonyl phenol (T-DET N-507). 
     The results are shown in Table 2. 
     
                       TABLE 2______________________________________        Goodwin Crude Oil Plus        300 ml Goodwin SyntheticGoodwin Crude        Water Containing 500 ppmOil Alone    T-DET N-507(300 ml)             Dial Reading                            Viscosity cpRPM   Viscosity cp            RPM     No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    5,100       6      1.5   4     200   80012    4,500      12      1.5   4.5   150   45030    3,800      30      2.5   6     100   24060    Off Scale  60      4     10     80   20030    3,920      30      2     6      80   24012    4,450      12      1.4   4     140   400 6    4,400       6      1.2   3.5   240   700Test Temperature        Test Temperature °F. 160.sup.(1) 145.sup.(2)°F. 190______________________________________ *Stopped stirrer, then waited two minutes before starting viscosity measurements. 
    
     EXAMPLE 3 
     This example is comparative and shows the viscosity values obtained on the crude alone and a combination of 50 volume percent crude and 50 volume percent water which contained 500 ppm of an ethoxylated polypropylene glycol containing 40 percent ethylene oxide and having a molecular weight of 2,000 (Pluronic L-44). 
     The results are shown in Table 3. 
     
                       TABLE 3______________________________________        Goodwin Crude Oil Plus        300 ml Goodwin SyntheticGoodwin Crude        Water Containing 500 ppmOil Alone    Pluronic L-44(300 ml)             Dial Reading                            Viscosity cpRPM   Viscosity cp            RPM     No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    3,500       6      1     OFF   200   Off                          Scale       Scale12    3,300      12      1.2   Off   120   0ff                          Scale       Scale30    3,480      30      3     Off   120   Off                          Scale       Scale60    Off Scale  60      6     Off   120   Off                          Scale       Scale30    3,520      30      1     Off    40   Off                          Scale       Scale12    3,608      12      2     Off   200   Off                          Scale Scale 6    3,100       6      2.5   Off   500   Off                          Scale       ScaleTest Temperature         Test Temperature °F. 160.sup.(1) 150.sup.(2)°F. 200______________________________________ *Stopped stirrer, then waited two minutes before starting viscosity measurements. 
    
     EXAMPLE 4 
     This example is illustrative and shows viscosity values obtained on the crude alone and a combination of 50 volume percent crude and 50 volume percent water which contained 400 ppm of the ethoxylated nonyl phenol of Example 2 (T-DET N-507) and 100 ppm of the ethoxylated polypropylene glycol of Example 3 (Pluronic L-44). 
     The results are shown in Table 4. 
     
                       TABLE 4______________________________________        Goodwin Crude Oil Plus 300 ml        Goodwin Synthetic Water Con-Goodwin Crude        taining 400 ppm T-DET N-507Oil Alone    and 100 ppm Pluronic L-44(300 ml)             Dial Reading                            Viscosity cpRPM   Viscosity cp            RPM     No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    3,900       6      0.6   0.6   120   12012    4,400      12      0.8   0.8    80   8030    Off Scale  30      1.5   1.0    60   4060    Off Scale  60      5.0   4.5   100   9030    Off Scale  30      2.5   1.5   100   6012    4,700      12      2.5   1.5   250   150 6    4,400       6      1.5   1.5   440   300Test Temperature         Test Temperature °F. 170.sup.(1) 155.sup.(2)°F. 200______________________________________ *Stopped stirrer, then waited two minutes before starting viscosity measurements. 
    
     EXAMPLE 5 
     This example is illustrative and shows viscosity values obtained on the crude alone and a combination of 50 volume percent crude and 50 volume percent water which contained 400 ppm of the ethoxylated nonyl phenol of Example 1 (T-DET N-407) and 100 ppm of the ethoxylated polypropylene glycol of Example 3 (Pluronic L-44). 
     The results are shown in Table 5. 
     
                       TABLE 5______________________________________        Goodwin Crude Oil Plus 300 ml        Goodwin Synthetic Water Con-Goodwin Crude        taining 400 ppm T-DET N-407Oil Aloneand 100 ppm Pluronic L-44(300 ml)             Dial Reading                            Viscosity cpRPM   Viscosity cp            RPM     No. 1 No. 2*                                No. 1 No. 2______________________________________ 6    2,200       6      0.5   6     100   1,20012    2,200      12      1.5   3.5   150   35030    1,760      30      3     3.5   120   14060    Off Scale  60      5     6     100   12030    2,040      30      3     3     120   12012    2,000      12      2     2.5   200   250 6    1,900       6      1.75  2.0   350   400Test Temperature         Test Temperature °F. 170.sup.(1) 160.sup.(2)°F. 200______________________________________ Stopped stirrer, then waited two minutes before starting viscosity measurements. 
    
     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.