SU1124118A1 - Method of fighting hydrate formation in gas-production equipment - Google Patents

Abstract

1. A METHOD FOR PREVENTING HYDRATE FORMATION IN A GAS-RELEASE PRODUCT, in order to increase the effectiveness of preventing hydrate formation while preventing the deposition of mineral salts in a gas well and body, in a gas well and body, in a gas well and body and in a well and in a well and body, and in the case of mineral deposits in the gas well and body, and in the case of mineral deposits in the gas well and body, and in the case of mineral deposits in the well and body, metal ammonium to a pH of at least 8, and then an inhibitor of salts in concentrations of 2.5-50.0 mg / l of produced water. 2. The method according to p. 1, that is, that methanol is injected with a salt common compound inhibitor K-1 | L-H Ng-Ro (he) g R :, and R can be - CH2-TH (OH) 2 where or R ;, -CH, -PO ((G) 2, and Rj can be 1-CH2-e -CI2 CH-CH2-S (OH) 2 CHj-POtOH) at X - (-CH-) OH p - can be 1-20; m 0,1,2.

Description

The invention relates to a gas industry that can be used to prevent hydrate formation in a gas well and downhole equipment. A known method of preventing hydrate / formation in a gas well, concludes with the search for the supply of electrolyte solutions (salts of carbon, nitric, phosphoric, sulfuric, hydrochloric acids) {11. However, the known method of combating rHjqjatothe formation does not provide the desired effect. The closest to the technologically unattainable and achieved result is a method of preventing hydrate formation in a gas well and well equipment by feeding methanol 2 into Well. However, this method does not have enough damage, because it does not eliminate deposits of mineral salts in the gas well. The purpose of the invention is to increase the effect of preventing hydrate formation while simultaneously preventing the deposition of mineral salts in a gas well and well equipment. The goal is achieved by those. According to the method for preventing hydrate formation, methanol in gas-field equipment is treated with alkali metal hydroxide or ammonium to pH not less than 8 before injection into the well, and then with salt inhibitor in concentrations of 2.5 - 50.0 mg / l produced water. In addition, a scale inhibitor of the general formula R, -N-CHj-PO (OH) 2 is introduced into methanol. where R and R. can be -CH, -U (OH) 2 2 or R. -CH, -PO (III); and R can be, - (- CH., - (- V) -CH ,,, - Yu (OH) 2 CH.-PO (OHL with X - (- CH-W p - can be 1-20, a m 0,1,2. The meta-pipeline used to deliver the scale inhibitor to the lift pipes of the gas well simplifies and cheapens the process {bending, since the day of the fight against the formation of methanol the system of delivery of methanol to the lift pipes of each well, and methanol is fed to the methane pipeline with a multi-plunger pump from one point. However, the use of the methanol duct system cannot be carried out according to the dosing scheme Deposits in methanol, since all known aminomethylene phosphonate mineral deposits inhibitors are not soluble in methanol at the necessary working concentrations to inhibit salt deposits. gas kondeisatiom field (OGKM) - 1.6 kg of methanol per 1000 m of natural gas; The working concentration of the scale inhibitor in m recoverable formation water is 2.5-50.0 g / m; average gas flow rate per well OGKM - 700,000 m of natural gas per day; The average water flow rate per well OGKM - 7m per day. Then for 1000 m of natural gas you need 1.6 kg of meta-; 700,000 m of natural gas — X kg of methanol, i.e. per day per well, requires: X - –120 kg of methanol. On 1 m of produced water, 2.5–50.0 g of scale inhibitor are needed, on 7 m of produced water - X g of scale inhibitor, X - 17.5–350 g of scale inhibitor. Thus, in 1120 kg of methanol, it is necessary to dissolve 17.5-350 g of a salt precipitating inhibitor, or 1000 kg of methanol 15, 0-312 g of a scale inhibitor. The following products produced by domestic industrial enterprises can be used as inhibitors of mineral H1H salts: nitrilotrimethylenephosphonic acid (NTF) of the general form: CH-PO (OH) N-CH2H-Yu (OH) CH2-GO (OH) and ethylethylene-polyamine-N-methylene phosphonic acid (PAF-1) of the general form: - () of the form: (HO), PO-rtl2-lfi; Hr jH-JH2-N t Hz-PO (OH) 2 CHi OH SNg „. , 0 (ОН1, lo (OH), in TABL. 1 the data on the stability of inhibitors of mineral deposits

ISO 150

one

1,150

+ It +

+ I- +

. $ 11 Ie, given in Table. 1, it can be seen that all the inhibitors of salt deposition considered by us are unstable in methanol at pH 6-7. and are completely stable at pH values of 8 and above. The type of alkaline agent used does not play a role in stabilizing a scale inhibitor in methanol. Since the introduction of a scale inhibitor to a gas well through a methanol pipeline system together with methanol is most acceptable, the effectiveness evaluation of the proposed method is illustrated as follows. For the experiments, water taken from well 333 on the OPSM and having the following M1sheral composition was used: Specific weight, 178 pH- 6.0, mg / l 79272.7 K-, mg / l1615 Ca, mg / l14749.4, MG / L2432 SG, mg / d155817.3 SOV, mg / l 767.4 FOG, mg / l Evaluation of the inhibiting ability is carried out by introducing the above composition, the calculated amount of methanol and the scale inhibitor into 750 ml of saline brine water sodium hydroxide, potassium or ammonium). In stainless steel glasses pour 200 ml of saline water containing methanol and salt inhibitor at the rate of 2.5; 5.0; 10.0; 50.0 mg / l produced water, after which part of the water is evaporated by heating. In the evaporation process, the remaining 550 ml of produced water treated with methanol, a scale inhibitor and an alkaline agent are continuously added, thereby maintaining the working volume in the glass constant. The effectiveness of the proposed method is judged by the amount of precipitate formed. The protective effect is determined by the formula: Where e is the protective effect from deposits of mineral salts,%; A - weight of sediment without the addition of a scale inhibitor, g; B - weight of sediment with the addition of a scale inhibitor, g. The data obtained are given in table. 2. Table 2

160

ol

2.5 160 5.0 160 10.0 160 50.0 160

one

2.5

160

5.0 160 160

10.0

50.0 160

160

2.5

DFT-1

NaOH NaOH

NaOH

79.6

76.1 87.4

84.2

89.6 93.1

100.0 100.0

NaOH

83.0

5.0 78.8

In tab. 3 shows the effectiveness of lowering the temperature of gas hydrate formation with methanol, methanol, pretreated with an alkaline agent, methanol, pretreated with an alkaline agent, and an inhibitor of deposits of 1 minerals.

Evaluation of the effectiveness of lowering the temperature of hydrate oxygen was performed in chambers with visual control of the onset of the process.

(Continuation of table. 2

hydrated using a microscope under static conditions. The pressure in the series of experiments reached 100 kgf / cm. The concentration of the hydrate formation inhibitor (methanol) is equal to 13.58% by weight of the mineralized formation water. The pH of methanol varied between 6 and 10. The density of the test gas is 0.555 (). The concentration of ingi & hydrophilic minor salt deposits with respect to methanol is in the range of 1.56-10 - 3.125; 10 weight%

Table 3

1124118

From the data given in table. 3 / it can be seen, 20 that the measurement of pH of metschol in the interval considered by us, as well as the introduction of the phosphorus-containing inhibitor of chroneal salts (DFT-1) into the pre-treated methanol with an alkaline agent, does not affect the negative tendency. 3

natural gas hydrate tours ..

In this way, the effect of preventing hydrate formation is increased, while at the same time preventing the deposition of mineral salts in the gas well and well equipment.

Claims (2)

1. METHOD FOR PREVENTING HYDRATE FORMATION IN GAS PRODUCING EQUIPMENT, comprising supplying methanol to a well, characterized in that, in order to increase the efficiency of preventing hydrate formation and simultaneously preventing the deposition of mineral salts in a gas well and downhole equipment, the methanol is pumped into the metal by hydraulic injection or ammonia up to pH not less than 8, and then a scale inhibitor at concentrations of 2.550.0 mg / l of produced water. 2. The method according to π. 1, because of the fact that a scale inhibitor of the general formula is introduced into methanol R, - ^ - eH ₂ -R0 (0H) _d GDS R, and k can be -CH ^ -PO (OH) or B -CHRO (OH) _2, a Rj may be a 1-CH ₂ - (X } -CH ₂ -vN-] _f ch ₂ -RO (OH) ₂ CH ₂ -P0 (0H) at X = - (- CH -) = OH η - can take values 1-20; m = 0,1,2. 1 1124118