RU2095119C1 - Method of dehydrating crude oil - Google Patents

Abstract

FIELD: crude oil treatment. SUBSTANCE: crude oil stream to be treated is divided into equal parts, each being affected by magnetic field and submitted to settling in small-size tubular settlers. EFFECT: reduced demulsifier and power consumption. 1 dwg

Description

 The invention relates to the oil industry and can be used in the collection, preparation of oil in the fields, as well as in the dehydration of oil in oil refineries.

 There is a method of oil dehydration, which consists in the fact that the oil-water emulsion is treated with a demulsifier and then fed into the sump with three separate streams of oil, emulsion and water, creating counter flows in the sump (see Aut. St. USSR N 763450, class C 10 G 33 / 06, 1980).

 There are also known methods of exposure to a emulsion with a weak pulsed magnetic field in order to accelerate the sludge process (see Auth. St. N 495040, class B 01 D 17/02, 1973). A disadvantage of the known methods of processing the emulsion in a magnetic field is that the desired effect is achieved only with small sections of pipelines.

There is also known a method of dehydration and desalting of oil, which consists in the fact that the emulsion is treated with a demulsifier and drainage water, produce heating, coalescence, sludge, separation and purification of drainage water by filtering through a layer of oil, which is continuously updated by circulating through it dehydrated or desalted oil [ 1]
A common disadvantage of the known methods is the high cost associated with the use of expensive demulsifiers and high energy costs when heating an oil emulsion.

 In addition, these methods are focused on the use of bulky expensive apparatus, tanks and equipment.

 The aim of the invention is to reduce the cost of oil production and preparation.

 This goal is achieved by the fact that in the known method of dehydration of oil, which includes processing the emulsion and sludge prepared emulsion, the fluid stream supplied to the processing is divided into equal parts, each part in the stream is exposed to a weak pulsed magnetic field and sedimented in a small tubular sump, in which the selection of oil and water is made from mutually remote points in height.

 The proposed method can significantly reduce the use of expensive demulsifiers, eliminate heating of the emulsion to accelerate the sludge of oil and water. The use of a flux divider into equal parts makes it possible to use the most efficiently weak magnetic field with minimal energy consumption and small-sized tubular settling apparatus.

 The proposed method can be implemented on the installation shown in the drawing.

 The installation includes the following apparatuses and equipment: a supply pipe 1, a liquid flow divider into equal parts 2, a pipeline section for magnetic treatment of the emulsion 3, a tub sump-separator 4, a water seal 5, a gas piping of the liquid flow divider and sumps 6, a water extraction pipe 7 , a pipeline for the removal of oil 8, a pipeline for the removal of gas 9.

 The drawing shows the installation with 4 parallel sedimentation tanks, there may be 2, 3, 4, etc. (as required).

 The method is implemented as follows.

 Well production in the form of a gas-liquid mixture enters the equalizer 2 into the liquid flow divider 1 through the supply pipe. Each part of the stream is fed into a tubular separator 4 through a separate pipe. In this case, the liquid flow in the pipeline section 3 is magnetically processed. To equalize the pressure in the gas spaces of the settling tanks 4, the liquid flow divider 2 and the water trap 5, they are tied with a gas line 6. The tubular separator traps are installed on one horizontal platform, i.e. at the same height, which allows the pipeline to take water, oil and gas through combine the sumps, respectively, for water selection 7, for oil selection 8 and for gas selection 9. A water trap 5 is installed on the common water withdrawal line 7 to maintain the oil-water interface in the tanks at a given level. The sufficient height of the tubular sump separators (3-4 m) allows you to far push the oil and water extraction points in height, widely vary the height of the oil-water interface and thereby affect the quality of the selected oil and water, as at a high level of the oil-water interface, higher water quality can be achieved by lowering the quality of the oil, and at a low level of the oil-water interface, it is possible to increase the oil quality by water content due to the deterioration of water quality. If it is necessary to improve the quality of oil and water with such a preparation scheme, it is possible to connect additional tubular sump separators in series, since they are relatively cheap, they can be made from standard large-diameter pipes on their own in any enterprise.

 Thus, the proposed method of oil dehydration in combination with the use of small tubular sump separators, a fluid flow divider and precise regulation of the level of the oil-water interface using a water seal allows you to achieve the desired result. As preliminary experiments show, treating the emulsion with magnetic fields reduces the settling time of oil and water by 2–3 times, the use of small-sized devices with this method reduces the metal consumption of the unit by at least 2 times.

Claims (1)

 The method of oil dehydration, including processing and sedimentation of the emulsion, characterized in that the emulsion flow before treatment is divided into equal parts, each part of the flow is subjected to a pulsed magnetic field and sludge in small tubular sumps, while oil and water are taken from mutually remote points along height.