Oxidizing agent for harmless treatment of drilling waste solid water-based mud, and preparation method and application thereof

[0027] Example 1. Preparation of oxidant

[0028] The oxidant formula of the present invention: in parts by weight, 30-50 parts of active agent, 5-15 parts of dicalcium hydrogen phosphate, 5-15 parts of sodium pyrophosphite, 5-15 parts of methylene dithiocyanate, 20-40 parts of water.

[0029] In order to evaluate the performance of the oxidant of the present invention, the following oxidants 1-3 were prepared:

[0030] No. 1 oxidizer: in parts by weight, 30 parts of active agent, 15 parts of dicalcium hydrogen phosphate, 5 parts of sodium pyrophosphite, 15 parts of methylene dithiocyanate, and 20 parts of water.

[0031] No. 2 oxidizer: in parts by weight, 50 parts of active agent, 10 parts of dicalcium hydrogen phosphate, 10 parts of sodium pyrophosphite, 5 parts of methylene dithiocyanate, 25 parts of water.

[0032] No. 3 oxidant: in parts by weight, 40 parts of active agent, 5 parts of dicalcium hydrogen phosphate, 15 parts of sodium pyrophosphite, 10 parts of methylene dithiocyanate, 40 parts of water.

[0033] The preparation method of oxidant is as follows :

[0034] Step 1. Synthesis of active agent

[0035] The formulation of the active agent: in parts by weight, 5 parts urea, 15 parts glycolic acid, 15 parts nitrilotriacetic acid, 10 parts hydrogen peroxide (10%) and 5 parts water.

[0036] The synthetic steps of the active agent are:

[0037] (1) Dissolve 5 parts of urea in water to prepare an aqueous solution of urea with a mass fraction of 20% for use;

[0038] (2) Add 15 parts of glycolic acid, 15 parts of nitrilotriacetic acid, 10 parts of hydrogen peroxide (10%) and 5 parts of water into the reaction kettle, heating and stirring (stirring intensity 120-180 rpm), when the temperature rises Stir at a constant temperature at 120°C, stir and react for 2 hours, then slowly add the urea aqueous solution prepared in step (1), and continue to stir and react at 120°C for 1 hour. After the reaction is completed, the stirring is stopped, and the active agent is obtained after natural cooling.

[0039] Step 2. The compound of oxidant

[0040] Weigh each component according to the formula. Add dicalcium phosphate, sodium pyrophosphite, methylene dithiocyanate and water into the reaction kettle, stir at room temperature at a speed of 120 rpm, and add the active agent synthesized in step 1 after the dissolution is complete. Continue to stir at a speed of 120 revolutions per minute, and obtain a liquid product after evenly stirring. The liquid product can be further dried and crystallized at a temperature of 105°C to obtain the final product.

[0041] Example 2. Evaluation of water solubility of oxidant

[0042] The water solubility of the oxidant of the present invention is tested according to the following method: Take 3 glass beakers, each beaker is filled with 100ml of water, and respectively add the No.1-3 oxidant prepared in Example 1 into the 3 beakers. The dosage of the oxidant is 30 grams After shaking well, let it stand at room temperature for 5 minutes to observe the dissolution of oxidant. The results are shown in Table 1. The oxidizing agent Nos. 1-3 has good water solubility.

[0043] Table 1 Water solubility evaluation table of oxidant

[0044] Oxidant Solution appearance Dissolution rate (%) Oxidizer No. 1 Soluble 100 No. 2 oxidizer Soluble 100 No. 3 oxidizer Soluble 100

[0045] Example 3. Evaluation of the effect of oxidants

[0046] The No.1-3 oxidizer prepared in Example 1 was used to treat the waste solid water-based mud from drilling to evaluate the oxidation effect. The low-concentration solid water-based mud waste used in this experiment was taken from an oil field in Wuqia County, Xinjiang, and the high-concentration sulfonated water-based mud waste used was taken from the Xinjiang Tarim Oilfield.

[0047] The mud treatment method is: take a certain amount of waste solid water-based mud, weigh it and put it into a beaker, add 3%-10% of the total weight of the solid oxidant, stir evenly, make the oxidant and the mud fully mix, and keep the mud The moisture content of the beaker is above 30% (the method of maintaining the moisture content is sealing: after mixing the oxidant and water-based mud, wrap or sleeve the beaker with plastic wrap or a sealed bag the same size as the beaker, and then use rubber bands Tie it tightly), place it at room temperature for 3-5 days to fully react the oxidant and water-based mud, and finally take a sample to detect the organic content in the reaction product.