Patent GB-651721-A (GB)
Title: Methods of and apparatus for treating emulsified oil well streams to reduce the tendency of the oil to foam and break down the emulsions
IPC: C10G33/06
Filed: 1947-08-05
Abstract: <PICT:0651721/III/1> Crude oil, in the form of an oilwell stream containing dissolved gas and emulsified water, is purified by passing it through a first body of heated water, to release sufficient gas to reduce the tendency of the oil to foam during subsequent treatment, and then through a second body of heated water to break the oil-water emulsion.  In Fig. 1, the two bodies of heated water are maintained in a tank 10 which is divided into two compartments by means of a dished partition 16.  The oilwell stream first enters a heat exchanger C through inlet 21 and passes from the heat exchanger to tank 10 through pipe 22.  Upon entering tank 10, the stream rises through the body of heated water which is maintained above partition 16, passing first through perforated plate spreader 26 and then through filter D, composed of excelsior, hay or fibrous material. Filter D, which is optional, aids in the breaking up of oil globules to release gas.  After passing through the body of heated water, the stream overflows down a series of baffles 32 into pipe 46, which carries the stream, via lateral pipe 55 and spreader 56, into the second body of heated water maintained in the lower compartment of tank 10.  The stream rises through this second body of heated water, past baffles 59 and through filter 60, <PICT:0651721/III/2> <PICT:0651721/III/3> <PICT:0651721/III/4> similar to filter D, and finally overflows through line 23 into heat exchanger C.  The purified oil is discharged from heat exchanger C through pipe 24 and may be drawn off through pipe 74. The first body of water is heated by means of a circulating heating system, water leaving tank 10 through pipe 40, and after passage through heater H returning to tank 10 through pipe 42. The second body of water is heated by means of return flue heater 57.  Water may be siphoned off from the first and second bodies of heated water by means of pipes 34 and 62 respectively and discharged through pipe 63.  Pressure-equalizing or gas transfer pipes 25, 33, 37 and 65 are provided.  Some condensation of vapours may occur in the gas space G, the condensate remingling with the oil, but the main bulk of gas is discharged through pipe 44 and may be drawn off through pipe 66.  If it is desired to redissolve the released gas in the purified oil to lower the specific gravity thereof, the gas, after passing through pipe 44, is led through pipe 71 into absorber K provided with bubble trays 83.  Purified oil enters absorber K through pipe 72, while oil containing dissolved gas leaves through pipe 81.  Fig. 4 shows a modification of the apparatus of Fig. 1, wherein, if desired the oilwell stream may be treated to release some gas before it enters the first body of heated water. The oilwell stream, which has come either from pipe 92 or heat exchanger C, is fed into a gas separator J by means of diverter 48, which directs the flow circumferentially around the inner surface of the separator, thereby causing release of gas.  The stream falls down flume 51 into the first body of heated water, while the released gas passes through openings 50 into gas scrubbing shell 49 where any liquid drops down drain 52 and gas passes out through pipe 68.  In Fig. 5, the two bodies of heated water are maintained in tank 100, the first body being in a central flume 101, while the second body surrounds the flume 101.  The oilwell stream enters the first body of heated water through pipe 105 and rises till it overflows down pipe 112 into the second body of heated water.  Purified oil is discharged through pipe 114.  Fig. 6 shows a modification of the apparatus of Fig. 5 wherein the oilwell stream is treated to release some gas before it enters the first body of heated water. The oil well stream enters gas separator S, similar to gas separator J of Fig. 4 and falls down pipe 124 into the first body of heated water maintained in flume 101.  After rising through the first body of water, the oilwell stream overflows down pipe 127 into the second body of heated water. Then it rises through perforations 1091 and purified oil is finally discharged through pipe 114.  U.S.A.  Specifications 2,181,685, 2,181,688 and 2,297,297 are referred to.