WO2008000115A1 - A procss for removing polymer and zooglea from crude oil - Google Patents

Abstract

A process for removing polymer and zooglea from crude oil comprises oxidizing-demulsifying crude oil for 10-25 minutes by stirring at a rate of 75-150 r/min under a temperature of 45-75 and adding a demulsifier at a concentration of 100-300 ppm, followed by three phases separation to remove polymer and zooglea from crude oil. The crude oil obtained from this process is easy to be electrically dehydrated.

Description

 Method for removing polymer and bacterial micelles from crude oil

 The invention relates to a method for treating crude oil, in particular to a method for removing polymers and bacterial micelles in crude oil. Background technique

 Since primary oil recovery (depending on the natural pressure of the formation) and secondary oil recovery (water injection pressure) have not been able to provide sufficient oil reserves to meet the increasing demand for crude oil resources, efforts have been made to meet the demand for oil production in the national economy. Develop oil recovery and actively carry out tertiary oil recovery. One of the most important tools in tertiary oil recovery technology is polymer flooding technology. Polymer flooding is suitable for reservoirs with moderate temperature, medium viscosity of crude oil (5-100 mPa·s) and relatively heterogeneous heterogeneity.

 Polymer flooding technology began in the United States in the late 1950s. From the 1970s to 1985, the United States conducted a total of 183 polymer flooding field tests, with a maximum recovery rate of 8.6%. In addition, in the former Soviet Union's Orleans and Arlan fields, Canada's Horsefly Lake field and Courtenay test area, and Germany, Oman, etc., also carried out polymer flooding industrial tests, generally improve oil recovery 6-17% .

 Domestic polymer flooding technology developed rapidly in the 1990s. The polymer flooding technology was first successful in Daqing Oilfield. From 1987, the field trial of polymer flooding began. In 1997, the production of polymer crude oil increased by 1/10 of the crude oil production in that year, which became an important technical means for stable production. Following this, pilot fields such as Shengli, Dagang, Henan, and Liaohe have also conducted pilot tests and achieved success.

 With the widespread application of polymer flooding technology, the problems encountered have gradually increased. A large amount of polymer added during the production process is glued together with fungal gums, petroleum colloids, asphaltenes, etc. to form a water/oil type stable colloid, which leads to difficulty in dehydration, causing protective power-off of the electric dehydration system, and interference. The normal operation of the gathering system. Therefore, crude oil containing polymers and fungal micelles cannot enter the dewatering system and cannot be transported into waste. It has gradually become an important limiting factor restricting the safe and stable production of oil fields and environmental protection.

 At present, domestic and foreign treatment technologies for polymers and bacterial micelles in crude oil are mainly concentrated in:

 1. Take measures to reduce the amount of polymer used to mitigate the effects of polymers on the properties of crude oil. However, as far as the current oil recovery is concerned, with the rapid development of polymer flooding technology, the amount of polymer used will become larger and larger, so it is difficult to solve this problem fundamentally.

 2, demulsification dehydration method

 (1) Demulsification-gravity separation: A demulsifier is added to the crude oil to be treated for treatment, and then sent to a purified oil settling tank. After dehydration, it is sent to the crude oil receiving tank. The main advantage of this treatment process is that the technology is simple and the energy consumption is low. The disadvantage is that this method cannot remove the polymer, the micelles, the gums, the asphaltenes and the like, and the dewatering of the treated crude oil is still difficult and cannot meet the process requirements.

 (2) Demulsification-water washing-gravity separation: Compared with the above method, the method increases the water washing process, improves the removal rate of water-soluble compounds and ions, but does not remove the polymer and the micelles in the crude oil.

 (3) Demulsification-swirl separation: “When the crude oil to be treated is broken, the two-phase separation is carried out by using a swirling technique, and the purpose of dehydration can be achieved, but the polymer and the micelle in the crude oil cannot be removed.

 None of the above methods can remove the poly's and the micelles in the crude oil, so that the electric dehydration cannot be successfully completed.

 It can be seen that there is no report in the prior art that the polymer and the micelles in the crude oil can be removed, thereby completing the electrical dehydration smoothly.

 Summary of the invention

 SUMMARY OF THE INVENTION An object of the present invention is to provide a method for removing polymer and bacterial gum in crude oil to smoothly perform electric dehydration.

 In order to achieve the above object, the technical solution adopted by the present invention is:

Taking crude oil as a raw material, oxidizing and demulsification, and then performing three-phase separation to remove the polymer and the micelle in the crude oil; Wherein, the oxidative demulsification is to oxidize and demulsifie the crude oil by adding the demulsification agent at a concentration of 100-300 ppm under the condition of stirring speed of 75-150 r/min and heating temperature of 45-75 °C. The residence time is 10-25min;

 Wherein: the three-phase separation is a high-factor three-phase separation technique with a separation factor of 9000-14000 for oil, water, and solid three-phase separation of oxidized and demulsified crude oil, wherein more than 85% of the polymers cause electrical dehydration The fungal micelles are separated from the crude oil by the solid phase, and ions which are not conducive to electrical dehydration are separated from the crude oil by the aqueous phase. The demulsification agent is an amine and an epoxide block polyether.

 M

 Technical advantages of the present invention:

 1. The method of the present invention adds an oxidative demulsification agent to the crude oil to be treated, and fully oxidizes and demulsifies the crude oil to effectively separate the polymer and the micelles from the crude oil.

 2. The separation technology used in the method for removing polymer and bacterial gum in crude oil is high-factor three-phase separation, and the removal rate of polymer and bacterial micelle in the separated crude oil is as high as 85% or more, and the quality of crude oil is greatly improved. , can be smoothly dehydrated. The recovered crude oil recovery rate is in compliance with the output standard and the processing cost is low.

 DRAWINGS

 Figure Example 1 After treatment, the original dehydration curve o

 1 is the oil line o map.

 Fig. 2 is a graph showing the electric dehydration of crude oil after the treatment of Example 2.

 Figure 3 shows the polymer and fungal mass solids separated in a three-phase separator.

 Figure 4 shows the polymer and the micelle o solid phase separated in the three-phase separator.

 detailed description

 The present invention will be further described in detail below with reference to the embodiments.

 Example 1

 The raw materials are as follows: polymer containing polymer and fungal group 0. 15-0. 25%, water containing 10-30% crude oil (this example takes crude oil from Daqing Oilfield), the specific implementation method is as follows (see Table 1):

 (1) The crude oil to be treated is introduced into the reaction tank and heated to 60 ° C; at the same time, the mixture is stirred at a low speed, and the stirring speed is 90 r / min. (2) Under the conditions of constant temperature heating and constant-speed stirring, a demulsification agent having a concentration of 150 ρππι and 250 ppm, respectively: a fatty amine polyoxypropylene polyoxyethylene block polyether. The crude oil stays in the reaction tank for about 15 minutes, and fully acts with the demulsification agent.

 (3) Separating the demulsified crude oil in a three-phase separator with separation factors of 10,000 and 13,000, respectively. The crude oil is separated into oil, water and solid three-phase by high-efficiency separation method. The polymer and the micelles are separated from the crude oil by the solid phase (see Figure 3). Most of the ions are separated by the aqueous phase, and the separated crude oil is electrically dehydrated.

 Figure 1 shows the current-voltage curve at a concentration of 150 ppm and a separation factor of 10,000. It can be seen from the figure that the current of the electric off-system is within the normal range, which can ensure the normal operation of the electric dehydrator. After treatment, the crude oil has a water content of less than 1.8% and can be exported to the outside by electrohydration. ,

 Table 1 Polymeric bacteria micelle removal results in crude oil

60 Stirring speed (r/min) 90 Reaction residence time (rain) 15 Dosing concentration (KM) ■ 150 250 Separation factor 10000 13000

 Example 2

 The difference from the embodiment 1 is that the raw material is 0. 3-0. 5 %, the crude oil containing less than 10% water, and the demulsifier is: polyethene polyamine poly Oxyethylene polyoxypropylene ether. The polymer and the micelles are separated from the crude oil by solid phase (see Figure 4), and the separated crude oil is subjected to electrical dehydration.

 Figure 2 shows the current-voltage curve at a concentration of 300 ppm and a separation factor of 14,000. It can be seen from the figure that the current of the electric off-system is within the normal range, which can ensure the normal operation of the electric dehydrator. The water content of the crude oil after processing is less than 0.9%. , reach the standard directly outside the loss.

 Polymer and bacterial micelle removal results in crude oil

 Example 3

 The difference from the embodiment 1 is that the raw material is 0. 05-0. 1%, the water containing 30-40% of the crude oil, and the demulsifier is: phenolamine resin Polyoxyethylene polyoxypropylene ether. The polymer and the micelles are separated from the crude oil by the solid phase, and the separated crude oil is subjected to electrical dehydration. The current of the electric off system is within the normal range, which can ensure the normal operation of the electric dehydrator. After treatment, the crude oil has a water content of less than 2.7%, and can be exported to the outside by electrohydration.

 Polymer and bacterial micelle removal temperature in crude oil (c) 45 Stirring speed (r/min) 75 Reaction residence time (min) 10 Dosing concentration (P 1) 100 200 Separation factor 9000 12000 9000 12000 Polymer and gelatin Group removal rate

 85. 5 90. 1 88. 6 92. 4

 ( % )

Claims

Claim A method for removing polymer and bacterial micelles in crude oil, characterized in that: crude oil is used as a raw material, which is oxidized and demulsified, and then subjected to three-phase separation to remove polymer and bacterial gum in crude oil; The oxidative demulsification is carried out by adding a concentration of 100-300 ρρπι demulsification agent to the crude oil under the conditions of stirring speed of 75-150 r/min and heating temperature of 45-75 ° C, and the reaction residence time is 10-25niin.  2. The method for removing polymer and bacterial micelles in crude oil according to claim 1, wherein: said three-phase separation is performed by a high-factor three-phase separation technique with a separation factor of 9000-14000 for oxidative demulsification. The original sleeve is separated by oil, water and solid three-phase. Among them, more than 85% of the polymer and the micelles which are difficult to be electrically dehydrated are separated from the crude oil by the solid phase, and the ions which are not suitable for electric dehydration are separated from the crude oil by the aqueous phase.  A method of removing a polymer and a micelle in a crude oil according to claim 1, wherein the demulsification agent is an amine and an epoxide block polyether.