Method for enhancing filtering performance of filter material

Abstract

The invention discloses a method for enhancing the filtering performance of a filter material. The method comprises the following steps: 1) discharging sewage in the filter material; (2) adding the hot fluid into the filter material to enable the water-soluble polymer or / and polymer residues in the filter material to be decomposed or / and crushed by heating so as to improve the backwashing effect of the filter material; and 3) carrying out backwashing on the filter material by using backwashing water so as to enhance the filtering performance of the filter material. The problem that the filtering speed and filtering performance of the filter material are seriously influenced by water-soluble polymers and emulsified oil can be effectively solved, and the problem that the backwashing and cleaning effects of the filter material are poor can be effectively solved; the method has the advantages of being easy to implement, safe, reliable, wide in application, easy to popularize and the like.

Description

technical field [0001] The invention relates to the field of oil and gas production and / or water treatment, in particular to a method for enhancing the filtration performance of a filter material. Background technique [0002] At present, a large amount of sewage generated in the process of crude oil exploration and production usually needs to be filtered by a filter device and then reinjected into the oil layer or formation. [0003] Such as figure 1 As shown, the filter device generally includes a housing 100 , a filter material 101 , a backwash water inlet valve 102 , a filtered water outlet valve 103 , a sewage inlet valve 104 , and a backwash water outlet valve 105 . The process principle can be summarized as follows: the sewage entering the housing 100 from the sewage inlet valve 104 passes through the filter material 101, and the suspended solids 106 contained in it are intercepted by the filter material 101, and then leave the housing through the filtered water outl...

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Problems solved by technology

[0010] However, at present, after the water-soluble polymer flooding method is applied to the oil wells under the jurisdiction of the joint station, the polymer content of the sewage after removal is about 20mg / L, and the suspended solid content is as high as 360mg / L or more; although the four filter tanks used in the station The material is still the mixed filter material of quartz sand + walnut shell, and the backwashing intensity (i.e. backwashing water flow rate) is increased by 1.5 times, and the backwashing frequency (or frequency) is increased by 1 times (i.e., after filtering the sewage for 4 hours, it can be used after filtration. However, the suspended solids content of the sewage filtered by the filter tank is still as high as 70mg / L, and the suspended solids content of the reinjected sewage is still as high as 60mg / L, which has exceeded the water injection in clastic rock reservoirs. The water quality index and analysis method SY / T5329-2012" and Shenyang Oilfield stipulated that the water injection index is more than 30 times, which has led to a substantial increase in the pressure of the water injection system; moreover, the pressure difference between the inlet and outlet of the filter tank is higher than that of the oil well using the water-soluble polymer flooding method The amount of filtered water (or filtration rate) is more than 60% lower than that before the water-soluble polymer flooding method was applied to the oil well, and the amount of backwash water increased by more than 150% compared to the oil well before the water-soluble polymer flooding method; As a result, the joint station is currently unable to use the existing 4 filter tanks to meet the task of sewage filtration

[0011] 2. The method of soaking and washing the filter material with detergent or / and acid and alkali is ineffective, and cannot effectively solve the problem of slow filtration rate of the filter material and substandard water after filtration

[0013] In order to solve the problems of slow filtration speed, increased pressure difference, poor backwash effect, greatly reduced filtered water volume and substandard filtered water of the existing 4 filter tanks, the joint station conducted a chemical cleaning production test of the filter tank filter material , the results show that: after adding detergent or / and acid and alkali into the filter tank to fully soak and wash the mixed filter material of quartz sand + walnut shell, the suspended solids content of the filtered sewage is still greater than 30mg / L, which is the same as that of the filter material There is no significant difference before washing with detergent or / and soaking in acid and alkali, and all of them do not meet the water injection indicators stipulated in "Water Quality Indicators and Analysis Methods for Clastic Reservoir Injection SY / T5329-2012" and Shenyang Oilfield; After the material is soaked and washed with detergent or / and acid and alkali, there is no significant change or improvement in the pressure difference of the filter tank, the filtration rate of the filter material, the amount of filtered water, the amount of backwash water and the frequency of backwash

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